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DESIGN WITH KNOWLEDGE New research in sustainable building Edited by Signe Kongebro Published by Henning Larsen Architects With contributions by Michael Jørgensen, MSc, PhD student Martin Vraa Nielsen, MSc, PhD, Sustainability Engineer Jakob Strømann-Andersen, MSc, PhD, Sustainability Engineer Translated by Cecilie Qvistgaard

Contents

Foreword 5 By Danish Minister for Climate, Energy and Building Martin Lidegaard

1.0 Introduction 7 By Signe Kongebro 2.0 What is sustainability? 11 By Signe Kongebro and Jakob Strømann-Andersen 3.0 Theory meets practice 14 4.0 4.1

      Geometry 21 Case : Novo Nordisk Corporate Centre Case : Viborg City Hall      Geometry in the city Case : Nørrebro City District Case : Klaksvík City Centre

5.0 5.1

      Comfort 43 Case : Kolding Campus – University of Southern Denmark Case : Klostermarksskolen      Comfort in the city Case : Västra Dockan Case : King Abdullah Financial District

6.0 6.1

      Functional layout 65 Case : Energinet.dk Office Building Case : Siemens Headquarters      Functional layout in the city Case : Thomas B. Thrigesgade Case : Carlsberg City District

7.0 7.1

      Daylight 87 Case : Umeå School of Architecture Case : Campus Roskilde      Daylight in the city Case : Nørrebro City District Case : Thomas B. Thrigesgade

8.0 8.1

      Materials 109 Case : Spiegel Headquarters Case : Novo Nordisk Corporate Centre      Materials in the city Case : Nørrebro City District Case : King Abdullah Financial District

9.0

      New roles, new collaborations 127 A+E :3D Energimål.dk What about Daylight? Multi-functional concrete The Adaptable House

10.0 Energy renovation and complete renovation By Signe Kongebro

138

Research articles 142 List of publications 143 Integrated Energy Design in Master Planning Summary of PhD thesis by Jakob Strømann-Andersen

145

The Urban Canyon and Building Energy Use : 146 Urban Density versus Daylight and Passive Solar Gains By Jakob Strømann-Andersen and Peter Andreas Sattrup Integrated Energy Design of Large-Scale Buildings Summary of PhD thesis by Michael Jørgensen

157

Investigation of Architectural Strategies in Relation to Daylight and Integrated Design By Michael Jørgensen, Anne Iversen and Lotte Bjerregaard Jensen

158

Integrated Energy Design of the Building Envelope Summary of PhD thesis by Martin Vraa Nielsen

173

Quantifying the Potential of Automated Dynamic Solar Shading in Office Buildings through Integrated Simulations of Energy and Daylight By Martin Vraa Nielsen, Svend Svendsen and Lotte Bjerregaard Jensen

174

Project overview 186 Glossary 190

4 | DESIGN WITH KNOWLEDGE

Foreword In 2020, Denmark’s emission of greenhouse gases must be reduced by 40 %. The building stock accounts for a substantial part of the total energy consumption in Denmark. In order to meet the ambitious goal, it is thus necessary to have particular focus on buildings : new and old commercial and residential buildings ; office buildings and single-family houses ; public and private buildings. We must incorporate all types of buildings. New buildings must be more energy-efficient, and we must look at the existing building stock which has a large potential for energy renovation. The regulation of the entire Danish building stock and energy/ climate policies are closely connected. With this holistic approach, we have taken an important step towards a greener future. Several investments in energy-efficiency and an overall strategy for energy renovation of buildings are on their way – a strategy that will pave the way for how we actually meet the objective of reducing energy consumption and future-proofing the entire building stock. This is an extensive task, and it is important that as many people as possible contribute with their experience and positions. It is possible to develop a building where aesthetics, energy- efficiency and architectural design form a synthesis. There are numerous Danish and international examples of this, and there is a connection. Sustainability adds another quality to buildings – incorporating sustainability demonstrates that

you assume responsibility for reducing energy consumption and improving the environment. Public-private partnerships have shown to have a beneficial effect as the road from politics to practice becomes shorter. The political visions for a future where society handles natural resources with more care and respect stand much stronger when supported by the business community and private initiatives. When policies and knowledge are transformed into practice, it benefits green growth in Denmark. Investments in energy renovation and energyefficiency can make a significant difference for our economy and create jobs as they support our possibilities in a continuously growing global market for knowledge on green solutions. This book on ’design with knowledge’ is based on a research collaboration between a private company, Henning Larsen Architects, and a research institution, the Technical University of Denmark (DTU). The collaboration has not only resulted in new knowledge but also in a number of specific examples that show that it is possible to reach the climate goals if we think before we act and work together across professional fields. The book is built on a public-private collaboration and bridges the gap between aesthetics and utility value.

Minister for Climate, Energy and Building Martin Lidegaard, June 2012

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Low-energy building is far too often considered a solely technological discipline. However, genuine low-energy is achieved through broad, crossdisciplinary collaboration between engineers and architects and is incorporated into the building from the very beginning. 6 | DESIGN WITH KNOWLEDGE

Introduction The environmental impact of the existing building stock and new buildings must be reduced. Incorporating scientific knowledge on climate and energy into the design process adds a new quality to the architectural design. In Denmark, we have a long tradition for environmentally conscious building. However, the building sector still accounts for a substantial part of total energy consumption. Architecture can save energy in itself if developed with a knowledge-based design approach. That is genuine low-energy. This book presents the tools and methods that have been developed as a result of a unique, crossdisciplinary research collaboration between engineers and architects. We have been used to solve building-related problems by means of expensive, technical solutions. The research of this book reveals that between 40 and 50 percent of the energy consumption of a building is determined by the design. Therefore, architecture must assume responsibility and qualify the design already in the preliminary design phase so the completed building does not consume more energy than necessary. In terms of resources, this is the most efficient way to minimise energy consumption.

 etween 40 and 50 percent of the B energy consumption of a building is determined by the design. In Denmark, eco-friendly and energy-efficient solutions have featured high on the agenda since the 1970’s. During the most recent decade, and in the years prior to the climate summit in Copenhagen

in 2009, the agenda got a new lease of life and weight. Although the climate crisis was considered a controversial assertion only ten years ago – more politically than scientifically documented – most sceptics today agree that the climate crisis is real. Addressing the climate crisis involves everyone. We must handle nature’s resources with care and carefully consider how our consumption impacts the environment and the life conditions of future generations. Therefore, a sustainable mindset has become relevant in many connections. And even though sustainability is most often considered a holistic discipline – where environmental, social and economic aspects form a synthesis – investments have often been based on far too short time perspectives. The approach has been that investments should be profitable and that costs should be recouped within a few years. When at the same time, the most popular investments in sustainable building have been made in expensive engineering services and costly technological solutions ; the holistic approach has been out of balance. Economy is part of reality and both public and private investments should be based on responsible prioritisation. This research presented by this book looks into alternative strategies for sustainable building than those that have been trend-setting in the industry for decades. Many paradigms are challenged in the following chapters, and our hope is that the challenge will result in a paradigm shift in the building DESIGN WITH KNOWLEDGE |

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1.0 Introduction

by Signe Kongebro

industry – where architects allow more knowledge to be incorporated into the creative processes  ; where engineers learn to contribute in the early design stages ; where we realise that low-energy is not just a matter of more technology, where sustainability is about more than energy and environment and also creates a social change ; where economic calculations are based on longer perspectives because it pays off.

tect’s everyday work and have made it possible to reduce the distance between knowledge and its application in the building sector. The collaborations have dealt with both existing knowledge and new research – with the primary objective of promoting a holistic appreciation of the environmental and energy-related aspects of building. An important step has been taken in terms of bringing together professions that usually work separately.

Henning Larsen founded his own studio in 1959 as a result of his great commitment to architecture. This has been a common thread during the more than 50-year-long history of the studio, and still is. Knowledge of and access to state-of-the-art knowledge and developments are decisive to create works of architecture that relate to current challenges faced by society. Architecture always creates a change and therefore it must also provide responses that reach beyond the functional and aesthetical questions raised by the individual projects.

Henning Larsen Architects is a creative workplace where the atmosphere is bustling with ideas and projects that are at the peak of their creation process. A thesis from the Technical University of Denmark (DTU) – where two civil engineering students worked on one of Henning Larsen Architects’ projects in the early design stage – revealed that up to 80 % of the energy consumption is determined by the design. This demonstration of how the design in itself puts a sharp limit to how much energy that can be saved in a building resulted in a research project that looked into this issue.

 he key to aesthetic, comfortable T and energy-efficient buildings is found in the interaction between architecture and technology. In 2008, Henning Larsen Architects established a number of cross-disciplinary collaborations. Some have since been completed. Others have been established. Research and innovation in dialogue with other professions have become part of the archi8 | DESIGN WITH KNOWLEDGE

Even though the tightening of Danish building regulations means that today only 40-50 percent of the energy consumption is determined by the design, it remains clear that the energy consumption of the design must be simulated and adjusted before the creative process is completed. The architect must assume part of the responsibility, and the design must contribute to saving energy. In the research collaboration established between DTU and Henning Larsen Architects under the industrial

1.0 Introduction

PhD scheme, the students have conducted ‘live’ research on the projects. The research has been based on three parallel PhD projects which together provide a holistic insight into the parameters influencing the energy consumption of a building.

defined by the adjacent buildings. Jakob StrømannAndersen's research also shows that there is a great potential in focusing more on daylight in the planning of cities and considering daylight as an important common resource.

The tools and methods described in this book are the result of the research conducted on a variety of building projects – for the majority not hypothetical or theoretical projects. With a few exemptions, the projects have either been completed or are under construction. It is unique to deal with research projects that have already had such direct influence before publication of the final PhD articles. The three PhD research projects have had each their own focus area : master plan, facade and building spatiality.

Michael Jørgensen has examined the connection between the different building parameters that influence energy consumption. His research has looked into the design of new buildings and the dynamic potential found in the interaction between geometry, building physics, components and system solutions. The research illustrates that the right dimensioning of spatialities, volumes and an optimised organisation of building functions minimise the need for technical installations – ventilation, cooling and heating – and that they constitute a complex landscape of variables that must be counterbalanced in order to energy-optimise a building.

Research and innovation in dialogue other professions have become part of the architect's everyday work. Jakob Strømann-Andersen's research shows that urban development plans and master plans have far larger influence on the energy consumption of cities and buildings than known until now. The design of master plans has a very direct influence on the buildings within the master plan and has a significant impact on the energy consumption of the individual buildings. The building volumes and their orientation influence each other : daylight, microclimate, wind and noise conditions are partly

Martin Vraa Nielsen's research on facade design and its influence on the energy consumption of buildings represents an area where architects and engineers have to define a ‘modus operandi’ with room for the competencies of both professions. The facade form an important element of the architectural expression of a building and at the same time serves to regulate the inflow of daylight and sun and thus the indoor air quality. The facade openings, the design and size of windows interact with the technical installations : solar protection, climate control, insulation and the connection to other system solutions in the building. The research shows DESIGN WITH KNOWLEDGE |

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that the facade design can activate significant energy and comfort-related potentials.

buildings is found in the interaction between architecture and technology.

The research projects have dealt with complex issues, which this book presents by means of short texts about the most important aspects in building design and urban planning. The researchers have worked on real projects and have thus had direct influence on the building design in a number of cases. In order to make the conclusions of the research projects accessible to a broad audience, the projects are presented in a simple, graphic way that briefly sums up the analyses and solutions brought into play on the projects. The method is the same for all projects – but the individual parameters vary depending on the objectives and context of the projects.

The research-based approach to the projects presented in this book has made it possible to present a wide range of specific, sustainable building solutions. The book can be read as a simple report on the results or as a catalogue of specific – and in most cases realised – solutions as an inspiration to others, professionals or laymen, interested in architecture. It can be read by everyone. In the back of the book, you find lists of the PhD students’ published articles and three research articles in full length.

We need a broader understanding of low-energy building. Far too often, it is considered a purely technological discipline. However, genuine lowenergy is incorporated into the building from the beginning – it does not become obsolete and cannot be saved. And it is possible to integrate all functions and values into one functional and aesthetic unit. For instance, correct use of daylight results in reduced energy-consumption and happy users. Low-energy is about much more than technology. Daylight is the strongest means of creating an architectural experience of space. At the same time, it can be used to achieve a good indoor air quality and optimal daylight conditions in a building. The key to aesthetic, comfortable and energy-efficient 10 | DESIGN WITH KNOWLEDGE

The research collaboration between the Technical University of Denmark and Henning Larsen Architects is financed by the industrial PhD scheme under the Danish Ministry for Science, Innovation and Higher Education. At DTU, particularly Associate Professor Lotte Bjerregaard and Professor Svend Svendsen have been engaged in the project and have supervised the students. The research project could not have been realised without support from the Realdania Foundation and the goodwill and great interest of the clients whose projects are included in the book as cases. Thanks to Jakob Strømann-Andersen, Martin Vraa Nielsen, Michael Jørgensen, Peter Andreas Sattrup and all colleagues who have contributed to the cases of the book. Happy reading.

What is sustainability ? The term of sustainability is not new. However, it did not become a central concept in society until the recent decade. Today, you talk about sustainable investments, sustainable policies, sustainable production – and of course sustainable building. Sustainability has become a necessary concept to address for companies and organisations that wish to demonstrate responsibility as regards climate and energy. However, the widespread use of the concept of sustainability has entailed that it now seems to cover all and nothing. But sustainability is more than just a term – and working with sustainability and integrating it as part of your business strategy require a more profound appreciation of the concept.

Sustainability is a precondition for both our presence and our future. Sustainability is a complex term, and if you wish to work with sustainability as a design parameter to reduce, optimise and produce energy, you have to start by limiting the concept and thus reduce its complexity. Even though many researchers, philosophers and practicians have done it, there is still a need for a general consensus of what sustainability covers. To start somewhere, Henning Larsen Architects has chosen to work with sustainable design that reduces the energy consumption of buildings in operation. The work with sustainability has a long political history, rooted in the alternative political movements after the Second World War, particularly in the 1960’s. The UN’s first global climate summit took place in Stockholm in 1972. This led to the establishment of the UN World Commission

on Environment and Development in 1983 – also known as the Brundtland Commission. In 1987, the Commission published the Brundtland report, which provided the foundation for a broader and more innovative understanding of sustainability. The report resulted in a global UN Conference on Environment and Development in 1992 in Rio de Janeiro. The outcome of this conference was the Rio Declaration, which comprises a range of principles for sustainable development and which really put our handling of nature’s resources and its consequences at the top of the agenda. Not only individuals, companies and organisations but entire industries recognise that they have a social responsibility and must consider how to promote a sustainable development. Green is the new black, as put by a wide range of media. The Danish building industry quickly supported and got involved in the work to promote a greener development, accepting that sustainability is a precondition for both our presence and our future. It is a challenge for all players dealing with sustainability : The effects of sustainable initiatives are often so wide-ranging that it sometimes results in lack of overview and blind navigation. Many people become paralysed by the large responsibility that follows with the ambition of sustainability because it requires a ‘both/and’ rather than an ‘either/or’. The work of a number of people who have defined and thoroughly examined narrow fields of sustainability has resulted in a range of more or less DESIGN WITH KNOWLEDGE |

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2.0 Definition

by Signe Kongebro and Jakob Strømann-Andersen

explored strategies that can be incorporated into present work in the field of sustainability. Instead of solely focusing on environmental certifications – that all have a raison d’être – the basis of this book has been a holistic approach, drawing on certifications to the extent necessary. Today, the predominant understanding of sustainability has three sides : society, economy and environment. They are all related. They represent a large mechanism, consisting of many gear wheels that turn around and move the other wheels. Every little gear on the wheel can be considered an agent that influences its whole. Every movement results in a wide range of derived effects. For instance, the effects of reduced CO2 emissions are so complex that they cannot be considered as a whole. Where should you set the limit then? You can talk about short and long chains of derived effects. The process from cause to effect can consist of few or many decisions on which agents to use in order to reach your objective. Every single decision is a step that makes it more difficult to intuitively understand the connection between cause and effect. The more agents, the harder it is to comprehend. Thus, there is a great risk of being paralysed if you do not limit your focus. This complexity cannot be changed. Instead, the individual player must formulate strategies and take ownership of the ambition to transform sustainability from vision to result. The agents must 12 | DESIGN WITH KNOWLEDGE

produce measurable results. It is a delicate balance to simplify the complexity. Nuances are lost but the simplicity in return provides an operational foundation where a focused, motivated search can identify the possibilities. Thus, not all aspects of the holistic approach to sustainability are treated but the partial results become more and more qualified because we learn from our decisions during the process.

Energy reduction is a concrete, operational strategy that puts the complex field of sustainability into words and practice. At Henning Larsen Architects, we have made the concept of sustainability tangible by focusing on energy reduction as the primary strategy. We have done this with a belief that focus on energy can create quality all the way round. The specific gear wheels, agents, have been developed with the objective of creating value for all three aspects of sustainability, that is, economically, socially and environmentally. The results of this strategy are a combination of energy benefits and non-energy benefits. These constitute two completely different sets of values – but what is common to them is that they both add specific value to the built environment. You can compare this balanced approach to a sound mixer with many knobs to adjust – and where the unique sound from recording to recording is generated by the specific settings.

2.0 Definition

Energy reduction is a concrete, operational strategy that puts the complex field of sustainability into words and practice. It is a tool to understand the direct connection between the derived effects of sustainability and an effective means of quantifying and qualifying sustainability in the built environment.

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3.0 Methodology

Theory meets practice A large part of the energy consumption of a building is determined by the design. This makes it necessary to incorporate knowledge at an early stage of the creative process and abandon ingrained habits and divisions of roles in the building industry. Sustainability is a complex concept. It cannot be reduced to a question of energy alone. However, in the research collaboration between the Technical University of Denmark and Henning Larsen Architects, which forms the foundation of this book, this has been a natural way to limit the concept of sustainability. Reduction of the energy consumption of buildings in use is an operational strategy. In cases where the scientific method has had a well-established theoretical foundation, the close collaboration between researchers and architects has been based on a more flexible work method, adaptable to the specific conditions of the project.

Reduction of the energy consumption of buildings in use is an operational strategy. While making the first sketches, energy reduction must be at the top of the agenda – as this is the phase where the framework and preconditions for the energy consumption after completion are established. This requires knowledge of how architecture and aesthetics impact the energy consumption – as regards height, width, orientation and a number of other elements. The potential for energy savings is reduced if the various possibilities have not been considered and analysed from the beginning. With a creation process that acknowledges the connection between design and energy consumption, 14 | DESIGN WITH KNOWLEDGE

you avoid having to incorporate costly technical solutions into the project at a late stage in order to compensate for poor choices made in the preliminary design phase. A building based on a clear sustainable strategy from the very beginning provides optimal possibilities for making use of the passive properties in relation to indoor air quality and optimised heating, cooling, ventilation, daylight etc. The design becomes energy-efficient in itself as the need for energy is minimised. That is genuine low-energy. A building can always be optimised at a later stage with state-of-the-art technology – but if it is optimised from the beginning, the basis for energy savings is improved compared to buildings where the energy aspect has not been incorporated at an early stage. In other words, it is a basic quality and value of the design – and building – that the creative process is guided and shaped by knowledge. And experience shows that it does not have a limiting effect on the creative, intuitive process. Rather, it is an opportunity to rethink the role of architecture, based on new knowledge and new goals. Where the traditional role of engineers is to quantify architecture, it is the role of architects to qualify it. However, the two are not mutually exclusive. Aesthetics is quantified through energy reduction, and energy reduction is qualified through aesthetics. Combining the theoretical knowledge of the engineer with the practical approach of the architect results in better architecture.

Experience

New knowledge

Development projects

Energy design

For instance Multi-functional concrete (cf page 135)

Materials

For instance The Adaptable House

Urban planning

New projects

For instance What about daylight?

The research is based on actual projects at Henning Larsen Architects. The produced knowledge has been tested in development projects and has found its way to new projects.

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PRODUCER

OPTIMER

REDUCER

In the future, building projects must be approved according to Danish building regulations and the EU’s new requirements for energy consumption and indoor air quality, Energy Performance Building Directive (EPBD). There are already talks that Danish requirements for the energy consumption of buildings will be increased by approx. 25 % in 2015 and an additional 25 % in 2020.

The objective of the method is to eliminate the need for energy." With a combination of stricter requirements and current technology, there is no way about it. Climate control in buildings cannot be solved with technology alone. It would require so much energy to meet the requirements with a traditional, mechanical system that the increased energy requirements would not be met. Energy design is a necessary part of the creative process. The best foundation for a successful project and a good place to start is to formulate a common objective for sustainability. This ensures that all collaboration partners have the same goal in the process and work constructively to achieve this. It is essential to provide the framework for an operational and integrated design process based on measurable criteria. This gives a smooth, open process where it is possible to work more systematically with the most central criteria and agents. The key to achieve synergy effects is to put research 16 | DESIGN WITH KNOWLEDGE

The practical work with sustainability can be described by means of a pyramid structure where the different agents are divided into reducing, optimising and producing measures.

and measurable criteria on the agenda in the creative process. Even though Integrated Energy Design was defined as the framework for the research collaboration described in this book, the method showed to be less effective in the everyday work than expected – and therefore, a modified, simpler version has become our applied work method. Integrated Energy Design considers energy consumption as an active co-player in the early design process. Measurable agents validate the different project stages, and the design is adjusted in accordance with parameter variations and impact assessments. The measurable agents do not only serve to continuously validate the project ; for every single simulation of a provisional design, a design alternative is provided. Thus, the aesthetic design is developed on the basis of actual measurements – which provides a quality control of the building. The process consists of many small steps where the agents are continuously adjusted. Every single adjustment adds new knowledge and clarity to the project and the project team. The final design is not to be reached in the first sketch ; instead, the design is developed and informed during the process. The simplified Integrated Energy Design method applies a wide range of specific agents. The practical approach to sustainability is illustrated by a three-level pyramid where each level represents a way to achieve energy reduction.

f

 is necessary to take decisions in the right It order during the process. Registration/analysis of functions, climate and context is an important start.

1. REDUCE by means of good design 2. OPTIMISE by means of technical solutions 3. PRODUCE by means of integrated, renewable energy The most significant energy reductions are achieved by means of passive strategies that only require thorough preparation and an intelligent use of resources. Passive properties are effective in the entire life span of the building as they are the building. Therefore, a reduction of the energy need is the first logical step and the foundation of the pyramid. The light, space and design of the building influence its performance.

It is essential to provide the framework for an operational and integrated design process based on measurable criteria. Energy-optimisation by means of technical installations costs extra. This typically means that expenses for e.g. a better ventilation system are higher. However, costs are recouped within a relatively short period in the form of lower operating costs and reduced CO2 emissions. The last step, the top of the pyramid, represents the integration of renewable energy – an agent that has a positive effect on the energy balance, but also a costly one and the one with the shortest life span at the moment. Agents of this kind only create energy-

related value and not for instance improved utility value. The objective of the Integrated Energy Design method is to eliminate the need for energy by means of an iterative process where technical specialist knowledge brings about the creative process, while aesthetics and space are the means of achieving significant energy reductions. In this way, aesthetic and rational parameters are qualified in one grasp. The research draws on experience from previous projects, which have been classified and thematised. The conclusions are brought into play in development projects until the new knowledge can be activated in new projects (cf diagramme page 15). It is when design architects and project groups work with specific agents in specific cases that the produced knowledge is unfolded, activated and further developed. This methodical strategy creates a dialogue between many different types of projects – where communication of knowledge is inseparably bound up with collection and adjustment of this knowledge. It is a slow process where learning how to implement existing knowledge as well as the constant generation of more knowledge is a point in itself. The incorporation of knowledge must become an inherent part of the creation process and thus an intuitive practice.

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Reduction of energy consumption must be high on the agenda in the early sketch phase. This is when the framework and preconditions for the energy consumption of the building are determined.

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What we do Henning Larsen Architects’ Sustainability Department conducts research on daylight, eco-friendly materials, facades, energy and sustainable urban development. A cross-disciplinary team forms the backbone of the department. Incorporating all aspects of environmental, social and economic sustainability is a natural part of all projects. It is an essential quality of the projects that they address these issues. Where we do it Sustainability can be implemented at all levels – in terms of materials, buildings and cities. Urban planning The master plan establishes the vision for a large urban area. The vision unites the many wishes and dreams into a story that is easy to communicate and can form the basis of the following process and dialogue. Buildings Buildings should meet many different – and often conflicting – requirements, and it seems that these requirements are increasing. The building geometry is difficult to change. It must be durable and last for many years whereas the technical installations can continually be improved. Materials The selection of materials is one of the most visible green building strategies. Materials can be evaluated on the basis of two criteria : 1. How do the reclamation, production, application and disposal of the material impact the environment? 2. How do the selected materials affect user health and comfort? A well-defined strategy for materials results in a healthy indoor air quality.

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The discipline of architecture is to design buildings. However, a building design not only constitutes an aesthetic expression. The geometry, position and orientation of the building largely influence the total energy consumption of the completed building. 20 | DESIGN WITH KNOWLEDGE

4.0 Geometry

Geometry One of the most important elements of architecture is geometry. The architectural experience is decided in the design process. The outer geometry and inner spaces determine the functionality of the building and give the building character. The basic geometries – the building volume and atriums, the spatial proportions and facade design, for instance the dimensions and depths of windows – form the configuration of the building and are the most difficult elements to change. Technical installations can be replaced as improved technology become available and the user behaviour can be changed. Geometry forms an important part of the passive properties of the design – which do not consume any energy in the operating stage. The building’s orientation in relation to the sun and the adjacent buildings, its compactness, room heights and room depths have a substantial influence on the energy consumption – and thus the need for artificial lighting, heating and cooling.

Geometry forms an important part of the passive properties of the design – which do not consume any energy in the operating stage. The various parameters should be evaluated as a whole. By varying the parameters and simulating the consequences for the buildings, it is possible to optimise the design according to the formulated objectives for energy-efficiency. The connections between the various parameters are complex and influence each other both positively and negatively. The building’s orientation on the site depends on its use, as the light changes during the day and year.

In addition, the surrounding city or landscape has an influence on the building orientation. There is a difference between whether the building is situated in shadow cast by a large adjacent building or in an open landscape. It is a widespread view that energy-efficient buildings must be compact. Round buildings are thus considered more energy-efficient than square buildings as they have a smaller surface area and are thus less exposed to the climatic and urban context. PhD Michael Jørgensen’s research shows that compactness is a less important factor than often estimated. This owes to the fact that elements such as the amount of daylight and insulation thickness can increase or decrease the facade’s influence on the energy consumption. Today, many buildings are very well insulated and the energy loss thus small. Research shows that the balance between facade openings, room heights and depths – which distribute the daylight inside the building – is far more important. In modern building, this has a significant influence on the total energy savings. Geometry also supports the social interaction of the building. In an atrium, for instance, the daylight inside the building is distributed from within. This is a good example of how a design parameter influences several sustainable qualities in a building, both social and energy-related qualities. By optimising and qualifying the balance between these parameters, their quality is further strengthened. DESIGN WITH KNOWLEDGE |

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Novo Nordisk Corporate Centre in BagsvÌrd, Denmark, is inspired by Danish architect Arne Jacobsen’s old master plan for the area. The window bands are designed with a view to create optimal light conditions in the offices. The horizontal panels reflect the sunlight and heat away from the work spaces. 22 | DESIGN WITH KNOWLEDGE

Case : Novo Nordisk Corporate Centre The new Novo Nordisk Corporate Centre will house the company’s top management and 1,100 administrative employees. The functional, sustainable design offers the users optimal work conditions. The building is situated in a green, attractive park, inspired by the Danish forest landscape. The park landscape creates inseparable contact between the buildings and the green surroundings – and visually supports the green profile of the building and Novo Nordisk. Together, the new, relatively low building volumes and the existing, polygon buildings accentuate the new unifying centre of force, the circular main building. The design aims to create a dynamic setting for people to meet and new synergies to appear. The largest cylindrical office building covers six floors. The round building shape and spiralling, inner staircase in the atrium are inspired by the complex structures of the insulin molecule. The circular shape increases the amount of daylight by

17 % and very much contributes to achieving a low energy consumption. In combination with the building physics and energy-efficient installations, the geometry is used to reduce the total energy consumption. The compact building design minimises the need for artificial lighting, without impairing the level of daylight. Three cuts in the facade provide even the central core of the building with ample daylight. Other sustainable features in the building include green roofs and re-use of rainwater for watering the garden.

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4.0 Geometry

Bagsværd, Denmark 50,200 m2 Under construction

REFERENCE :

95 kWh/m2/year The project is based on the standards for traditional building as provided for in Danish building regulations BR08. This corresponds to an energy consumption of 95 kWh/m2/year. The objective for the project is to meet the 2015 energy requirements of Danish building regulations, corresponding to approx. 42 kWh/m2/year.

REDUCE :

95 kWh/m2/year

71 kWh/m2/year

Context The building is situated in a green park, to the joy of both employees and guests. The park creates a ‘cool island’ effect where the humidity and cold temperature of the ground contribute to reducing the difference between outside and inside temperatures. This minimises the energy consumption for cooling.

Orientation and position The building will form part of the existing Novo Nordisk complex in Bagsværd. It is situated in the south-east corner of the site and will function as a unifying element in the overall structure. The round building has no front or back side; it is oriented towards the sun and features three cuts in the facade that provide the far corners of the building with ample light.

Geometry The small surface area of the round building contributes to reducing heat loss. In addition, the room depths are optimised according to the need for daylight in the individual work spaces, which means that the inflow of daylight through the facade is increased by 17 %. In this way, the employees are offered more and better daylight.

24 | DESIGN WITH KNOWLEDGE | GEOMETRY | BUILDNIG

Daylight The round volume is perforated by three cuts, which together with the central atrium bring the daylight and the surrounding scenery into the very core of the building. The three cuts are oriented towards the primary access routes from the surrounding buildings.

Facade design The facade consists of classic window bands featuring horizontal, closed panels that reflect the sunlight and heat away from the building. The architectural expression is inspired by Arne Jacobsen who developed the master plan for the Novo Nordisk site in 1961. The embrasures are white and matt and bring reflected, diffused light far into the building.

Zoning The building is divided into two different indoor air quality zones, featuring individual control systems. The indoor air quality of the atrium varies according to the changing seasons and the atrium is typically colder or warmer compared to the rest of the building – depending on the season. The work areas, on the other hand, have a constant indoor air quality and are divided into local, individually controllable climate zones.

Green roof Adjacent to the cafeteria and lecture hall, two sloping volumes with green roofs connect the building to the surrounding park. The green roof surfaces delay the percolation of rainwater and additionally contribute to the ‘cool island’ effect as described under ‘Context’.

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OPTIMISE :

71 kWh/m2/year

41.8 kWh/m2/year

Glass type The ground floor and the first floor feature treble glazing, consisting of glass that is poor in iron. Sunlight more easily penetrates glass with a low iron content – thus, the use of daylight is optimised.

Lighting State-of-the art LED motion sensors have been applied in the atrium. In addition, the lighting concept offers a variety of different light levels and only applies ‘downlight’ LED spots.

Dry cooling The cooling system is optimised by installation of dry coolers.

PRODUCE :

41.8 kWh/m2/year

No producing measures The ambition of the project has been to meet the 2015 energy requirements of Danish building regulations, that is, approx. 42 kWh/m2/year. This objective has been met solely by means of energy-reducing and optimising solutions.

26 | DESIGN WITH KNOWLEDGE | GEOMETRY | BUILDING

The atrium is the unifying element for all functions and spaces. The six-storey high space is defined by organically shaped balconies that open upwards to bring as much daylight as possible down into the building. The atrium ceiling features a fine-meshed skylight. DESIGN WITH KNOWLEDGE |

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Sustainability and distinctive architecture go hand in hand in Viborg City Hall. The green roofs of the base delay the natural percolation of rainwater, while at the same time accentuating the geometry of the floating building. In this way, the city hall is deeply rooted in the landscape. 28 | DESIGN MED VIDEN | GEOMETRI | BYGNING

Case : Viborg City Hall Viborg City Hall is Denmark’s first sustainable city hall. A compact building geometry and a holistic daylight strategy result in a total energy consumption that meets the 2015 energy requirements of Danish building regulations. Viborg was the first municipality that decided to build a new city hall after the Danish structural reform in 2007. The completed building is Denmark’s first example of a sustainable city hall. The new city hall is situated in a previous military area on the outskirts of Viborg. It is shaped as a sculptural volume, floating above a base of lower buildings that carefully adapt to the landscape. The building opens up to the city hall square and the new green park to the south and invites employees and citizens into the interior space characterised by brightness, openness and flexibility. Viborg City Hall has a total energy consumption that meets the 2015 energy requirements of Danish building regulations. This is partly achieved by means of passive, energy-reducing solutions integrated into the building design and partly through

energy-producing elements such as solar cells, groundwater cooling and heating. In addition, the building offers both staff and citizens a comfortable indoor air quality – based on a social, sustainable mindset. Thus, strong focus has been on exploiting the daylight as much as possible, both in the facade design and in the selection of materials and colours inside the building. In addition, the graphic expression of the facade provides the city hall with a distinguished identity and accentuates its significance for the city. According to the municipality’s own calculations, the sustainable building will reach break-even in just eight years.

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4.0 Geometry

Viborg, Denmark 19,400 m2 Completed 2011

REFERENCE :

95 kWh/m2/year The project is based on the standards for traditional building as provided for in Danish building regulations BR08. This corresponds to an energy consumption of 95 kWh/m2/year. The objective for the project is to meet the 2015 energy requirements of Danish building regulations, corresponding to approx. 42 kWh/m2/year.

REDUCE :

95 kWh/m2/year

71.2 kWh/m2/year

Context The building is located in a desolate military area along the inner ring road of Viborg. Situated in the corner between an industrial area to the north-west and an area of single-family homes to the south, the city hall rises in height towards the hard industry, while its green ‘arms’ towards the family homes and their gardens serve to down-scale and soften the building expression.

Orientation and position The city hall forms part of a whole, consisting of the building itself, the square and the park. The building is situated parallel to the north-west corner of the site, constituting the demarcation of the site towards the ring road. The park is situated south of the building between two green ‘arms’. The city hall square is located to the east, which is also where staff and citizens arrive to the building.

Geometry The sculptural building shape resembles a moulded cube that rises from three ‘arms’, thus creating a smooth transition between building and landscape. The slightly sloping roof of the building provides it with a dynamic outer expression and an interior characterised by unique spatial qualities.

30 | DESIGN WITH KNOWLEDGE | GEOMETRY | BUILDING

Daylight The three skylights of the large atrium allow the daylight to penetrate into the far corners of the building. The light flowing across the white balconies of the displaced floors changes the character of the interior space during the course of the day. The largest skylight is divided in two by a roof terrace, situated in connection with the staff cafeteria.

Facade design The patterned facade features deep treble glazing, serving both aesthetic and functional purposes. The deep relief serves as sun protection, while at the same time bringing the daylight far into the building by means of its silky matt surface. Not least, the facade design contributes to giving the building a dynamic, vibrant expression.

Zoning Viborg City Hall is a democratic building, which is also reflected in its organisation. Thus, the main space of the building – the atrium – is open to the public. Everyone has a right to experience and use this space, which also serves as arrivals area. The further into and up the building you go, the more private the functions become.

Green roof The green roof reflects the sun rays away from the building and transforms CO2 into oxygen. In addition, it helps to reduce the need for cooling, which has a positive influence on the total energy consumption of the building. Likewise, the green roof delays the percolation of rainwater on the site.

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OPTIMISE :

71.2 kWh/m2/year

61 kWh/m2/year

Natural ventilation The entire city hall offers natural ventilation, with the exemption of a few large meeting and conference rooms. The ventilation intakes are situated above ceiling level.

Lighting The lighting is regulated in accordance with the daylight. Motion sensors and energy-reducing light sources further reduce the energy consumption.

Thermo-active constructions Heating/cooling tubes are embedded in the concrete slabs. The slabs are exposed where possible to fully exploit the thermal properties of concrete. This reduces large fluctuations in room temperatures and improves the indoor air quality.

PRODUCE :

61 kWh/m2/year

41 kWh/m2/year

Groundwater cooling and heating Groundwater is collected from 90 metres below ground level and used for heating and cooling. Three different systems ensure use of the most efficient method available at the time. 760 m2 solar cells are installed on the building roof. The solar cells produce 76,000 kWh on an annual basis.

32 | DESIGN WITH KNOWLEDGE | GEOMETRY | BUILDING

The graphic expression of the facade provides Viborg City Hall with a distinctive identity. The special structure is based on analyses and simulations of the daylight flow through the building. Work spaces are placed in a way that prevents them from being negatively affected by direct sunlight. DESIGN WITH KNOWLEDGE |

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The simulations of Nørrebro city district in Copenhagen (cf page 36) have worked with adding and removing building storeys in order to examine the ability of daylight to reach street level and courtyards. By harnessing from the sun’s radiation when we renovate, we achieve more daylight in our cities and homes – in addition to lower heating bills and 34reduced | DESIGNenergy MED VIDEN | GEOMETRI | BYGNING consumption.

4.1 Geometry

Geometry in the city There is a large difference between whether you build in a historic city district in Scandinavian or in a new city district in the Middle-East. Building traditions and climate conditions make a difference. The density of the city and the design of the individual buildings also play a role. Contemporary cities are developed according to detailed plans providing detailed guidelines for a number of city-related aspects – from selection of materials to facades and infrastructure. These development plans provide the framework for the individual buildings and their energy consumption. The basic principles for energy-optimised buildings are defined by the immediate context. Buildings influence the microclimate and daylight conditions in other buildings. It makes a difference whether a building casts shadow on the adjacent building or reflects daylight into it. The master plan establishes the vision for a large area. The vision sums up the objectives and wishes for a number of aspects and is often the structural idea that links the buildings of the area. The master plan must have a robust structure that allows for variations and adjustments of the design over time. This flexibility makes the master plan future-proof for many years to come.

Daylight should be considered a common resource in urban planning. The contextual preconditions of the master plan form the basis of the building design. Therefore, it is decisive to look at the city structure and buildings in an energy-related context. Taking this holistic approach provides a better foundation for designing energy and comfort-optimised cities and

buildings. The interaction between city density and outer building geometries constitutes an essential parameter when dealing with energy-optimisation. PhD Jakob Strømann-Andersen’s research incorporates daylight as a key parameter – and the results draw a dynamic picture of the relationship between design and energy consumption. The impact of the city structure on the energy consumption of buildings is far more extensive than previously assumed. The research results indicate that there is a limit to city density of 200-300 % if you wish to base a master plan on an energy-optimising strategy. Daylight is one of the most important factors in building design – both in terms of the experience of the building and in relation to energy. Daylight should be considered a common resource in urban planning – and master plans should incorporate this aspect and acknowledge the possible energyrelated synergies between the different elements and typologies of the city. Buildings can create better conditions for each other in relation to sun, shadow and wind. Optimising the city structure is thus an important prerequisite for reducing the energy consumption of the individual buildings.

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4.1 Geometry

Copenhagen, Denmark 150,000 m2 Development project completed 2012

Case : Nørrebro City District In an existing city district, the building geometry can be adjusted by tearing down or adding new buildings and by reshaping the existing building stock. The objective is to achieve optimised daylight between the buildings and in the individual dwellings. Changing the structure of a city district is not something you ‘just do’. Many players are involved ; the time perspective is long and the consequences are complex. Therefore, the translation of knowledge from theoretical sun and shadow studies into practice relates to a more abstract level, that is : what we dream of. The city we dream of living in is open and green – but also so dense that the population size allows for public functions such as schools, supermarkets, retail and workplaces. The development project ‘What about daylight?’ examines daylight in a carefully selected ‘city lab’ in Nørrebro city district, Copenhagen. The daylight studies are based on a number of parameters, including geometry. The spaces and structure of the city largely influence the passability of daylight – both in the urban space and in the buildings. Geometry has a direct, 36 | DESIGN WITH KNOWLEDGE | GEOMETRY | CITY

measurable impact on the quality of our cities and dwellings. When working with the geometry of the city, the following agents can be applied : addition, demolition and planning of new roads and paths. Adding new building volumes in places carefully selected according to sun and light conditions results in unchanged or increased city density. Demolishing entire or parts of buildings allows the light to penetrate into even narrow, deep courtyards. Establishing new roads and paths across existing thoroughfares creates more and varied routes through the city district.

Geometry The heights of and distances between the buildings are decisive for the amount and quality of daylight – both in the building and in the urban space. The diagram illustrates how the horizontal angle is reduced. The higher up the floors you go, the more the angle is reduced and the more daylight pours into the space.

Daylight The passability of daylight in the city has a large influence on the quality of and human comfort in the outside space as well as in the individual dwellings. The development project in Nørrebro, which is a very dense district, has worked with removing entire building blocks to make the streets broader and allow the daylight to penetrate even the lower floors of the remaining buildings.

Solar design By means of ‘solar design’, it is possible to achieve more daylight, improved contact to the outside space, lower heating bills and reduced energy consumption. For instance, angled facades provide the outside space with more light and prevent the upper balconies from casting shadow on the flats situated below. Additionally, the increased net and gross floor area provides increased utility value.

Complete demolition

Partial demolition

New building

Extension

Measures Demolishing and/or extending entire or parts of buildings are two of the means of achieving sustainable cities, based on geometry as a key parameter. In the project in Nørrebro city district, the simulations have worked with adding and removing building storeys to allow daylight to pass through streets and courtyards.

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The master plan for KlaksvĂ­k City Centre in the Faroe Islands is based on a particularly strategic approach to geometry. The new buildings should contribute to reducing the powerful winds from the north-west and south-east which create an undesirable, chaotic microclimate.

Case : Klaksvík City Centre Klaksvík is a Faroese city that spans over two opposite mountain ridges, connected by a low-lying area where two inlets meet and where a new city centre will now be established. Comfort and microclimate have been keywords in the development of the master plan. The new city centre in Klaksvík is based on a continuous system of paths that connect three districts with each their own special identity. The three districts incorporate and strengthen the existing qualities of Klaksvík, revolving around different themes : a green, recreational area ; an urban area with public functions and services ; a maritime district with a cultural house, a maritime museum, cafes, shops, residences etc. along the promenade. The vision of the project is to create an adventurous and vibrant city centre. Thus, the central plaza of the urban area will offer a wide range of experiences throughout the day and year. In addition, the plaza will establish a natural connection to the sea and the maritime district.

conditions have been applied to ensure a good microclimate and comfort in an area where winds from the north-west and south-east are extremely powerful. In connection with the preliminary research for the project, it became clear that the answer to the project should be found in the history of urban planning in the Faroese Islands. The project introduces broken, displaced building volumes and streets to ensure a calm and comfortable microclimate – based on previous experience.

In the development of the new city centre in Klaksvík, simulations and studies of local wind DESIGN WITH KNOWLEDGE |

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4.1 Geometry

Klaksvík, the Faroe Islands 150,000 m2 1st prize winning competition project 2012

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40 | DESIGN WITH KNOWLEDGE | GEOMETRY | CITY

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Context The last 50 years’ urban development in Klaksvík has allowed winds to whistle through the streets without hindrance. As opposed to this, the new city centre draws on the refined historic experience and engages in dialogue with the local climate and landscape. This results in a city centre with a comfortable microclimate.

Connection to existing city The new city centre is based on a star-shaped structure where the centre of the star constitutes the new sheltered plaza, the heart of the city. The pointed shape roots the new urban space in the existing city. Conversely, it also brings the surrounding city space, green areas, canals and beach spaces into the new city plaza.

The master plan for KlaksvĂ­k City Centre and plaza is designed with a view to make the buildings provide shelter from the harsh winds. A good microclimate in the city is the first step towards more social interaction. DESIGN WITH KNOWLEDGE |

41

Comfort relates to the users’ sensuous perception of the building – and is thus highly connected to the indoor air quality and functionality of the building. By incorporating the indoor air quality in the preliminary design phases, you achieve significant financial savings and more aesthetic buildings. 42 | DESIGN WITH KNOWLEDGE

5.0 Comfort

Comfort People have an inherent ability to perceive and sense their surroundings – and people’s perception of a building is very much influenced by its comfort. The balance between energy consumption and comfort should be analysed and clarified in collaboration with the client and users. The design of buildings has a direct influence on how we live our everyday lives and use our physical surroundings. The relationship between users and building continuously evolves and is reflected by the users’ experience of the building and the energy consumption of the building. The indoor air quality is the common denominator that serves to enhance the users’ perception of the building and at the same time reduce the energy consumption.

a good indoor air quality to compensate for poorly designed buildings. This results in lower ceilings and everyday noise when large ventilation systems have to be installed. If the indoor air quality of the buildings is incorporated into the design from the beginning, the need for ventilation is reduced. This ensures significant financial savings in the construction and operation stages as well as more beautiful and more user-friendly buildings.

Indoor climate is often considered a question of steady temperatures and good air quality. However, if the user experience is incorporated, it is possible to get a step further. The users’ feeling of influence is decisive for how user-friendly they consider the building to be. The possibility to open a window to get fresh air or control the solar protection system is the users’ way of interacting with the building. Buildings should be intuitive. Research shows that users are ready to accept fluctuations in temperature, air quality, light strength etc. if they have the possibility to influence these conditions.

Indoor air quality can be divided into five categories : thermal, atmospheric, acoustic, visual and mechanical (as defined by WHO). Particularly, the thermal, atmospheric and visual indoor air qualities define the energy consumption, which means that large savings can be achieved by working actively with these three parameters.

 he users’ feeling of influence is T decisive for how user-friendly they consider the building to be.

The iterative process – where architects and engineers each contribute with their professional knowledge on comfort based on different parameters – forms a decisive part of the preliminary design stage. Sensuous perception and physical comfort should go hand in hand. By knowing and incorporating the needs of the users, building installations can be optimised, which ultimately provides significant energy savings.

In simplified terms, you can say that indoor air quality is equal to energy consumption – however, we have not always been so aware of this direct connection. Thus, energy is often used to create DESIGN WITH KNOWLEDGE |

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The University of Southern Denmark – Kolding Campus stands out with a varied, optimised indoor air quality. The large atrium contributes to distributing the daylight in the building from within and providing natural ventilation. 44 | DESIGN WITH KNOWLEDGE

Case : Kolding Campus – University of Southern Denmark With its triangular shape, Kolding Campus will stand out as a significant new landmark in Kolding. The campus will be Denmark’s first low-energy university with focus on comfort, indoor air quality and interaction. The new campus is located in the centre of Kolding close to the harbour and station. Kolding Campus creates a new central plaza by the scenic attraction of the river and will engage in close interaction with the educational institutions in the city. The shape and facades of the building ensure a powerful dialogue between the inner life of the building and the outside observer. The facade forms an integrated part of the building and provides the campus with a unique, dynamic expression. Inside, in the five-floor-high atrium, the displaced staircases and access balconies create a special dynamic atmosphere, where the triangular shape repeats its pattern in a continuous variety of positions up through the different floors.

dents, while at the same time offering spaces for quiet contemplation. By giving all users an errand on all floors, the number of cross-fields are maximised – and the vision of creating a learning centre of excellence gets optimal conditions for succeeding. The campus activities open up to the city so the campus plaza and the interior study universe become one continuous urban space. The project offers a wide range of green, sustainable solutions and meets the 2015 energy requirements of Danish building regulations. In the detailed design stage, architects and engineers have worked closely together to further optimise the design and maintain the high ambition level for the environmental sustainability of the building.

Each floor is organised with a view to create crossfields between professors, researchers and stuDESIGN WITH KNOWLEDGE |

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5.0 Comfort

Kolding, Denmark 13,600 m2 Under construction

REFERENCE :

95 kWh/m2/year The project is based on the standards for traditional building as provided for in Danish building regulations BR08. This corresponds to an energy consumption of 95 kWh/m2/year. The objective for the project is to meet the 2015 energy requirements of Danish building regulations, corresponding to approx. 42 kWh/m2/year.

REDUCE :

95 kWh/m2/year

88.8 kWh/m2/year

Context The new campus building in the centre of Kolding is located by the river and close to the harbour. Situated adjacent to Kolding Design School and International Business College Kolding, the new Kolding Campus will become part of a dynamic study environment.

Orientation and position Kolding Campus is located in the north-east corner of the site. The rotated position of the building creates a sunny central plaza between the campus and the river and prevents a direct north-facing facade with no sunlight.

Geometry The triangular shape of the building ensures an optimal use of square metres. The large, rotated atrium provides the building with both ample daylight and a view to all world corners. At the same time, the atrium provides supplementary natural ventilation and night cooling.

46 | DESIGN WITH KNOWLEDGE | COMFORT | BUILDING

Daylight Achieving the right amount of daylight in a building is a balancing act between use of large, open windows and shielded windows. The orientation and design of the skylight protect the interior from direct sunlight – as too much light can have a negative impact in the form of increased cooling and ventilation requirements. The atrium provides optimal daylight conditions in the heart of the building.

Functional layout Kolding Campus offers a good, differentiated learning environment with different indoor air quality zones. The building has two climate zones. Teaching and administration facilities are situated in the zone closest to the facade, which has a stable indoor air quality. The atrium has a more fluctuating indoor air quality – allowing the users to sense the changing seasons.

Facade design As part of the daylight strategy, a dynamic, mobile solar protection system has been developed for the facade. It consists of a light structure of movable, triangular elements, which regulate the daylight intake, as well as a heavier, well-insulated structure. The opening angle of the facade is approx. 50 %.

Heavy structures Kolding Campus is part of a development project (cf page 135) which examines how the thermal properties of concrete can be increased – and the energy consumption for heating and cooling thus reduced. In order to make optimal use of the thermal properties of concrete, the slabs are exposed where possible. This prevents large fluctuations in temperature and improves the indoor air quality.

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OPTIMISE :

88.8 kWh/m2/year

57.9 kWh/m2/year

Lighting Kolding Campus features needs-based lighting. Energyefficient LED lighting has been applied in the entire building.

Mechanical ventilation A mechanical, needs-based VAV (Variable Air Volume) ventilation system with high efficiency has been installed in the building. The system works together with the thermo-active structures. Vapour-permeable ceilings ensure a low pressure loss and reduce the amount of pipes and fittings.

PRODUCE :

57.9 kWh/m2/year

38.4 kWh/m2/year

Aquifer Thermal Energy Storage (ATES) Kolding Campus features a combined heating and cooling pumping system, which uses groundwater to regulate the building temperature. The fully integrated system works together with the other building installations, which for instance apply the outside air for cooling.

Solar cell system A solar cell system on the roof produces electricity.

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In the five-floor-high atrium, the displaced stairs and access balconies create a dynamic atmosphere. The triangular shape is repeated in new compositions up through the different floors and creates a close dialogue between the inside and the outside. DESIGN WITH KNOWLEDGE |

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Henning Larsen designed the school Klostermarksskolen in 1960. Today, 50 years later, Henning Larsen Architects has completed an energy renovation of the school – a new building envelope of glass provides an improved indoor air quality and increased comfort for teachers and pupils. 50 | DESIGN WITH KNOWLEDGE

Case : Klostermarksskolen The school Klostermarksskolen is one of the earliest projects of Henning Larsen and was inaugurated in 1965. After 50 years of use, the school needed renovation. A new building envelope designed to accentuate the original expression of the school contributes to reducing the energy consumption of the building. The main objective of the renovation has been to reduce energy consumption, while at the same time ensuring improved indoor air quality as well as increased comfort and productivity among teachers and pupils. The overall idea of the project is a new, advanced building envelope of glass which makes the buildings appear as floating volumes, thus accentuating the architectural expression of the school. In addition, the project comprises a new roofed courtyard between two wings, also made of glass. The courtyard features new seating stairs which provide the framework for social interaction and access to the teaching rooms of the two wings. The glass roof contributes to increasing the temperature in the wings in winter and extends the season for outdoor teaching to comprise spring and autumn as well.

Finally, the energy renovation of the school covers an exterior re-insulation of the roofs. In this connection, a new ventilation system, new skylights, acoustic ceilings and daylight-controlled lighting have been installed. Henning Larsen’s original project was recognised for its strong architectural expression. The high quality is maintained and strengthened in the new building envelope, which provides an aesthetic, contemporary framework for the school.

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5.0 Comfort

Roskilde, Denmark 1,000 m2 Completed 2012

REFERENCE : Klostermarksskolen was almost without insulation prior to the renovation. Calculations show that the new individual building parts each meet current energy requirements – and thus, the total energy consumption of the school has been reduced significantly.

REDUCE : Context Klostermarksskolen is situated in a mixed residential area. The building consists of an industrial, prefabricated construction of concrete. It comprises of a special class wing to the north-east and ordinary classes in the wings to the south-west, separated by courtyards in various levels.

Orientation The existing building is organised around an atrium with teaching rooms to the one side and rooms for creative production classes such as art, handicraft, home economics etc. to the other side. The building has a diagonal orientation relative to the points of the compass.

Geometry The original building geometry, which forms part of the renovation, consists of two teaching wings with a shared courtyard between them. Originally, the buildings featured overhangs above the windows, they were barely insulated and they were heated by an outdated system.

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Glass roof In connection with the renovation project, a glass roof over the courtyard between the two teaching wings has been established. The roofed space reduces heat loss in winter and optimises the indoor air quality in the buildings and courtyard.

Daylight The glass roof provides the courtyard with natural daylight. In addition, new skylights and the new building envelope of glass significantly increase the amount of daylight in the teaching wings.

New building envelope The new building envelope eliminates thermal bridges in the existing, exposed concrete structure. Old windows are replaced with new treble glazing, resulting in a significant improvement of the U-value.

Re-insulation Roofs, gables and ventilation houses have been re-insulated to meet current standards. The re-insulation minimises heat loss and reduces the costs for heating. By moving the ventilation system to the basement – which has a constant temperature – the energy consumption for ventilation is also reduced.

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OPTIMISE : Lighting New, daylight-controlled lighting has been established in the teaching wings. Together with the increased amount of daylight, this will reduce the need for artificial lighting and thus improve the indoor air quality.

Radiators In connection with the establishment of a new building envelope, new radiators have been installed. Their position and dimensioning reduce cold down-draught and optimise the air quality.

Natural ventilation Natural ventilation with heat recovery has been installed in the roofed courtyard. On warm summer days, the roof can be opened, allowing the warm air to flow out of the building. The low pressure will then draw fresh, cool air from a shaded area into the courtyard, creating a comfortable indoor air quality.

PRODUCE : Winter

Vinter

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Heat distribution BSim calculations have documented that the roofed courtyard generates heat for the teaching rooms in winter. In addition, the space between the buildings is heated to a temperature that allows for outside teaching through spring and autumn as well.

The skylights in the glass roof of the courtyard contribute to significantly increasing the amount of daylight in the teaching wings.

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The positioning and design of the public urban spaces in the master plan for Västra Dockan in Malmö, Sweden, are based on studies of the microclimate in the old industrial area. In the background, you get a glimpse of the backbone of the master plan – a green park connecting the city and harbour. 56 | DESIGN WITH KNOWLEDGE

5.1 Comfort

Comfort in the city The comfort of the urban spaces has a very direct influence on the development of a city. Wind, sun, shadow and daylight are all key elements determining the potential of the urban space to provide the framework for a dynamic city life. Cities compete to attract the best brains, businesses and culture to be abreast of developments. In the future, genuine metropolises will be sustainable cities. As is the case for buildings, the climate is a fundamental parameter in city planning. The climate is decisive for the design and development of cities. When looking at the city, particularly the spaces between the buildings are interesting : the free zones where the climate has room to unfold. The urban microclimate cannot be controlled mechanically as the indoor air quality. The building volumes dictate the local climate zones – and therefore, urban planners have a large responsibility when new master plans or redevelopments of existing areas are designed. The success criterion for a master plan is good urban spaces. In this context, climate conditions play an important role.

people’s ability to stay outside in the hottest summer months. Thus, a thorough examination of local climate conditions is decisive for optimal planning of the city, with the best possible comfort under the specific conditions. The aim for comfort means that buildings must be designed to incorporate the given local climate as a co-player. A planning strategy based on sun, shadow, wind and daylight analyses results in optimal comfort. By exploiting the available natural resources, the urban space can be optimised with few, simple means. The needs and wishes of the users are decisive for the development of successful urban spaces, and key parameters for the city identity. Energy consumption and urban planning strategies rely on the specific user behaviour – and the comfort of the urban spaces determines the sustainable potential of the city.

The needs and wishes of the users are decisive for the development of successful urban spaces. Good, attractive urban spaces go hand in hand with comfort. In Northern Europe, dark, humid spaces are the most dangerous enemy to city life – while sun/controlled wind conditions is a magnet for activity. In warm parts of the world, for instance the Middle East, shadow and the natural ability of wind to provide ventilation are prerequisites for DESIGN WITH KNOWLEDGE |

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5.1 Comfort

Malmö, Sweden 80,000 m2 Design year 2008

Case : Västra Dockan How do you transform an existing industrial harbour into a vibrant, dense city with mixed functions? In the competition proposal for Västra Dockan, Sweden, the answer to this question is based on a qualified green activation of the urban space. The Västra Dockan project introduces a master plan where the building volumes serve to create a mixture of streets and plazas, similar to the varied city district of central Malmö.

A – Stays of long duration B – Stays of short duration C – Activity D – Passage

The development of the harbour area takes the history of the location as its starting point ; the narrow alleys and large halls are actively incorporated to engage in dynamic interaction with a modern, urban harbour space with offices, retail, residences and recreational areas.

Thus, Västra Dockan takes a holistic, scientific approach to urban spaces and buildings that provides entirely new comfort and energy-related opportunities. For instance, the effect caused by shadow from adjacent buildings can be incorporated into the microclimatic calculations and the consequences of the wind and daylight conditions determined by the varied urban spaces can be clarified.

The plan is based on a quantitative approach that integrates the microclimate of the city, i.e. wind and daylight conditions. It is organised in four activity categories, defined by the level of activity in the urban space :

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This holistic approach has resulted in an urban space that offers a wide variety of different activity/recreation zones with each their own individual microclimate.

se

Offentlige parker; legepladser; indkøbsstrøg mv. Aktivt ophold; magelig og normal gang; slentre; spadsere; Gangsti; indgangsparti; indkøbsgade mv. Gennemgang; objektiv gang; rask eller hurtig gang Parkeringsplads; boulevard; fortov mv.

+ + -

Ophold at kort varighed; stående/siddende i kortvarig periode;

+ -

-

C

D

C

B

Ophold af længere varighed; rolig position; siddende eller liggende; Terrasse; gadecafe eller restaurant; pool; amfiteater mv.

+

B

Karréens gavle terrasseres mod det grønne indre strøg. Terrasserne skaber lys, ly og mangfoldighed i en menneskelig skala.

A

Kategori for aktivitet i byrummet.

D

C

Den kvantitative målsætning struktureres ud fra 4 aktivitets kategorier, der er defineret med udgangspunkt aktivitetsniveauer i byrummet. De fire klasser be-skriver minimums krav for vind- og sollysniveauet i det givne byrum.

KVANTITATIV MÅLSÆTNING Kategori for aktivitet i byrummet. Den kvantitative målsætning værdisætter designparametre for de mikroklima-tiske forhold i rummet mellem bygningerne, dvs. (vind, sollys, dagslys mv.). Der tilstræbes værdier, der ikke alene sikrer et højt komfortniveau i byrummet, men også sikrer gode forudsætninger for design af lavenergibebyggelser.

Formålet er, at gøre det udendørs miljø så behageligt som muligt under alle vejrforhold ved udelukkende at benytte passive strategier, dvs. strategier der ikke kræver et øget ressourceforbrug.

B

Karréens længer differentieres vertikalt med udgangspunkt i en naturlig optimering af lyset i byrummet. Samtidigt udvikles der skalahierarkier, der skaber områder med overgange fra lav til høj bebyggelse for at bryde den ensartethed, som et en gennemgående bebyggelsesstruktur ville skabe.

Karréens længer forskydes og vinkles horisontalt, udfra en bearbejdning af byens rumlige forløb samt en optimering af de mikroklimatiske forhold i byrummet.

Den fleksible funktionsbase rummer en kombination af service-, erhvervs- og offentlige funktioner. Basen skaber derved en kobling omkring forskellige sociale, fysiske og økonomiske paradigmer, der er med til at skabe diversitet i byen. Overgangen mellem det private og offentlige rum forskydes fysisk, men på samme gang bibeholdes den visuelle kontakt.

teknisk videnskabeligt syn på byrum og bygninger, der giver helt nye komfort og energimæssige muligheder, fordi effekten fra f.eks. skygge fra omgivende bygninger kan tages med i beregningerne, ligesom konsekvensen af vind- og dagslysforhold fra de varierende bylandskabelige udformninger.

A + Stays of long duration, quiet position, sitting or lying down

- Terrace, street café or restaurant, pool, amphitheatre etc.

+ Stays of short duration, standing/sitting for a short period

-  Public parks, playgrounds, shopping streets etc.

+ Active stays, comfortable and normal walking pace, strolling

D

A

Land use The organisation of the new buildings is based on a quantitative approach to the microclimate, for instance wind and daylight. The project applies values that not only ensure urban spaces of high comfort but also good preconditions for designing low-energy buildings.

- Walkways, entrances, shopping streets etc.

D + Passage, objective walk, rapid or quick walking pace

-  Parking spaces, boulevards, pavement etc.

Green loop The structure of Västra Dockan is based on a new green loop that runs through the area and connects it to the adjacent districts. Access to green spaces creates value all way round – economic value for the district and high social and health-related value for the people living in it.

Typology The project is based on the North European tradition for building blocks, which are adapted to the desired function of the building, sun/shadow conditions etc. This building type has been selected due to its characteristic courtyard which offers a comfortable microclimate and because it easily adapts to the wish for low-energy design.

Adaptation The building blocks are raised up to a continuous base and opened up towards the central green loop – allowing the green courtyards to merge with the green loop. Service and retail functions are placed in the base and residences on the upper floors with plenty of daylight. Ample daylight is provided to the interior building spaces by adjusting the heights of the building block ‘arms’ and by introducing a terraced structure towards the green loop.

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Riyadh is situated in the middle of the Saudi Arabian desert and the requirements for microclimate are extremely high. The geometric design of King Abdullah Financial District in Riyadh has a large impact on the comfort experienced between the buildings. 60 | DESIGN WITH KNOWLEDGE

Case: King Abdullah Financial District  

In a desert climate, it is a difficult challenge to create a comfortable microclimate. Temperatures are extreme. In the new financial district in the capital of Saudi Arabia, Riyadh, the optimised urban spaces result in lower temperatures between the buildings. King Abdullah Financial District merges the traditional Arab city with a modern metropolis. The heart of the district is a transformed imitation of the Saudi ‘wadi’, a low-lying area in the desert that becomes green after rainfall. In King Abdullah Financial District, the ‘wadi’ becomes an ever green, shaded recreational area with retail, restaurants and sports facilities. When dealing with comfort in the city, the largest challenge in the Middle East is to provide protection from the intense sun. Design measures can help to lower the temperature in the city. The financial district will become a green, luxuriant area with vegetation and water that contribute to reducing the temperature.

outdoor temperature can be lowered by up to 6-8 degrees. Today, people in Riyadh almost entirely get around in their own vehicle where air-condition ensures a comfortable temperature. King Abdullah Financial District introduces the first light rail in Saudi Arabia as well as closed footbridges between the buildings. Sustainable guides have been prepared for all district buildings, which have all been pre-certified for LEED. Specific, detailed guidelines are provided in relation to water consumption, energy consumption, indoor air quality, impact of microclimate, materials, waste management etc.

By optimising the building proportions and using light facade materials that retain humidity, the DESIGN WITH KNOWLEDGE |

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5.1 Comfort

Riyadh, Saudi Arabia 1,600,000 m2 Under construction

2.13

2.10 1.10

Land use Riyadh is situated in the Saudi desert where it is so warm that citizens prefer to go around by car instead of by foot. The master plan integrates an existing wetland whose cool microclimate is used for recreational areas and walking zones.

Microclimate The city is planned around the green wetland and shaped in a profile that is highest towards the middle and lowest along the district edge. In this way, warm winds and sandstorms are led above and around the city. This makes the city nice to stay in and reduces damages on buildings and infrastructure.

Density The district is most dense around the centre and least dense in the periphery. The dense structure provides shadow and a comfortable microclimate. The geometries of the buildings are based on specific design guidelines for each individual plot.

2.13

2.10 1.10

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Infrastructure The density of the city centre reduces the need for car transport. Saudi Arabia’s first light rail and around 100 roofed skywalks provide efficient infrastructure and reduce the total CO2 emissions of the district.

The dense centre of the financial district provides shade and creates a comfortable microclimate. Today, almost all transport takes place by car.

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The facades of Energinet.dk’s new office building on the outskirts of Copenhagen feature vertical, fixed solar protection panels, which protect the interior from direct sunlight and prevent overheating of exposed spaces. 64 | DESIGN WITH KNOWLEDGE

6.0 Functional layout

Functional layout Organising the building functions is one of the architect’s most important tasks. With a few sustainable tools, it is possible to develop a design that incorporates all essential aspects – flow, indoor air quality, energy-efficiency and architectural identity. In order to understand the potential of the built environment, the designer changes between scales in an iterative process. One of the elements which spans across several scales is functional layout, i.e. the organisation of the various functions in a building. An intelligent layout where functions are consolidated in sections and put together in accordance with the specific needs and resources is the key to successful buildings. The trick is to find a balance between a fluid and fixed functional layout. A well-defined distribution of functions is decisive to achieve an energyoptimised design. An effective strategy to achieve both is zoning, which consolidates functions in fixed zones, organised to allow for optimal synergy between them. The building must work optimally both in zones and as a whole.

Functional layout is not just a question of flexibility but also a means of optimising comfort. A robust organisation of functions ensures an efficient use of square metres. Waste space is avoided, which benefits both use patterns and energy consumption. This means that the client saves money for materials and energy, of benefit to both the economy and the environment. If functions are organised in a matrix of sections, you achieve a high degree of flexibility, which extends the life span of the building. A flexible functional layout

serves to future-proof the building because it can then be adapted to accommodate the needs of new users as well. If the distribution of functions is not thoroughly considered, it can create large problems for the indoor air quality and energy consumption. Placing functions without consideration for solar heat, for instance, bears the risk of overheated spaces. High temperatures and glaring reduce the level of comfort and efficiency among the users – and it costs both energy and money to regulate the temperature mechanically by means of ventilation, cooling or automatic solar protection, which is activated when the sun shines and prevents the user from looking out the window. Zoning makes it possible to adapt installations to the needs of the various functions. In this way, functional layout is not just a question of flexibility but also a means of optimising comfort. It is decisive for the overall flow and long-term adaptability of the building that the functional layout strategy is able to cover several scales. The functional layout is a significant element of the building identity. A successful building makes use of the context to for instance create a good indoor air quality.

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Even though Energinet.dk’s new office building on the outskirts of Copenhagen is a compact volume, daylight pours into the very core of the building without hindrance. Increased room heights and overhangs, which allow the building to provide shade for itself, ensure optimal daylight, sun and shadow conditions. 66 | DESIGN WITH KNOWLEDGE

Case : Energinet.dk Office Building The new office building for Energinet.dk’s employees in Ballerup, on the outskirts of Copenhagen, is a genuine low-energy building that achieves a low energy consumption solely by means of design and optimised geometry. The building covers 4,000 m2. A simple design makes the house flexible and easily accessible. It consists of three elements : meeting facilities, an atrium and work spaces. The meeting facilities are placed on the ground floor with a clear view of the landscape. This is also where employees and guests arrive to the building. The atrium is the open, active gathering point of the building. From here, the large, central staircase provides access to the work spaces on the first floor.

Part of the environmental objective has been to ensure a high degree of flexibility. The open layout of the first floor, the light walls and simple, reusable elements will make it easy and uncomplicated to change the interior layout in the future. When the building was designed, it met the requirements for lowest energy class solely through an optimised design.

The green roof of the building serves several sustainable purposes. It reduces the load on the public sewage system by means of slow percolation and evaporation. In addition, the collected rainwater is used for flushing the toilets and watering the garden, which contributes to reducing the overall energy consumption for cooling. DESIGN WITH KNOWLEDGE |

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6.0 Functional layout

Ballerup, Denmark 4,000 m2 Completed 2011

REFERENCE :

95 kWh/m2/year The project is based on the standards for traditional building as provided for in Danish building regulations BR08. This corresponds to an energy consumption of 95 kWh/m2/year. The energy goal for the project meets the energy requirements as provided for in BR08, i.e. approx. 52 kWh/m2/year.

REDUCE :

95 kWh/m2/year

62.9 kWh/m2/year

Context The building has a secluded location on a hilltop in a sparsely built-up industrial area. This has provided ultimate freedom in relation to the position, orientation and geometry of the building.

Orientation and position The building is situated in the southern part of the plot. Its rotated position means that it has a diagonal orientation in relation to the points of the compass. In this way, you avoid entire facades that face due east or south where they would be particularly exposed to direct sunlight.

Geometry The compact geometry of the building minimises heat loss and material consumption. The room heights of the various floors have been increased compared to normal, which makes it easier for the sunlight to pour all the way into the building.

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Daylight The building is lit by daylight from the large glass facades, by the skylight and by the atrium. The overhang of the top floor provides shade to the ground floor in summer, reducing the energy consumption for cooling.

Functional layout Functions that do not require long-lasting stays, such as meeting rooms, library etc., are placed to the south and east. The permanent workstations are placed to the north-west and north-east. In this way, the difference between internal and external temperatures is minimised just as the need for mechanical cooling is reduced.

Facade design The compact facades feature vertical, fixed solar protection panels, which prevent direct sunlight and overheating in exposed spaces. The solar protection system is designed according to the sun. It is deepest at the top where the sun is highest in the sky – to the south and east – and most narrow in places where the light needs optimal conditions to find its way into the building.

Heavy structures By exploiting the ability of concrete to absorb heat and cold from the surroundings, large fluctuations in room temperatures are prevented. This improves the indoor air quality and the energy balance.

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OPTIMISE :

62.9 kWh/m2/year

48.6 kWh/m2/year

Mechanical ventilation The building is fitted with a high-efficiency mechanical ventilation system, which ensures a constant indoor temperature of 21-22 degrees all year round. The balanced ventilation system features oversize pipes, which significantly reduces loss of pressure.

Heating/cooling Canals have been excavated under the building with a view to utilise the natural temperature of the ground for heating and cooling of fresh air.

PRODUCE :

48.6 kWh/m2/year

No producing measures The ambition for the project was to meet the standards of Danish building regulations BR08, corresponding to approx. 52 kWh/m2/year. This objective has been met solely by means of energy-reducing and optimising measures.

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The office building of Energinet.dk is lit by daylight from the facade, the large skylights of the atrium and a number of smaller skylights. Functions that do not require long-lasting stays such as meeting rooms are placed along the facades where the largest fluctuations in room temperature occur. DESIGN WITH KNOWLEDGE |

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The new global headquarters for Siemens in Munich is organised around a vertical structure that connects the entire building complex. The building integrates with the city and creates a number of public urban spaces at street level. 72 | DESIGN WITH KNOWLEDGE

Case : Siemens Headquarters Siemens’ new headquarters is an urban composition of plazas, courtyards and alleys that expand on the existing topography of the city and create a new, vibrant urban space in the city, open to everybody. The cutting-edge headquarters unites the Siemens organisation and Munich City into a harmonious whole. In recent decades, office buildings have traditionally been isolated outside the cities. Located as a continuation of the historic city district of Munich, the new Siemens headquarters breaks with this trend and opens up to the citizens at street level. The public access creates a continuous flow of guests and passers-by, manifesting the 21st century headquarters as a welcoming and engaging space. The headquarters consists of a large urban building block whose facade is clad in stone towards the surrounding streets. A number of cuts in the building block allow for a series of green courtyards to be created. The courtyards are encircled by modern, transparent glass facades, which serve to open up the building to the green spaces.

This structure ensures public accessibility and makes the building engage in close dialogue with the city – thus generating a new urban space to be explored. The heart of Siemens’ new headquarter is the atrium, placed in the middle of the building with access from all sides. The atrium is Siemens’ main entrance. With the design of the new headquarters, Siemens wishes to distinguish itself with a building that spearheads the development of sustainable design in an urban context. The project aims to exceed well-known green standards such as DGNB Gold and LEED Platinum. The building employs state-of-the-art energy and climate technology produced by Siemens and hence also serves as a demonstration of the company’s products. DESIGN WITH KNOWLEDGE |

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6.0 Programme distribution

Munich, Germany 45.000 m2 Under construction

REFERENCE :

153.7 kWh/m2/year The project is based on German standards for traditional building, which corresponds to 153.7 kWh/m2/year. The project aims to exceed existing certification standards in green building, DGNB Gold and LEED Platinum.

REDUCE :

153.7 kWh/m2/year

131.6 kWh/m2/year

Context Siemens’ new headquarters is situated on the periphery of Munich’s historic city centre. A large part of the existing building block will be torn down to make room for the new building, which joins together the museum quarter to the north-west and the old city centre to the east and south-east through the public connection across the building.

Position and orientation The Siemens project preserves two buildings from the existing complex – one of which is listed. The two buildings, which encircle one of the city plazas, are renovated and fully integrated into the new design. The wish is to strengthen the transition from the plaza into the building.

Geometry The geometry of the building is defined by the shape and size of the construction site. Due to the functional requirements and the total depth of the building, the building block will offer a unique spatial environment. Thus, the daylight strategy accounts for how the building depths of up to 18 metres and the narrow courtyards can be compensated for with regard to daylight.

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Daylight As a compensation for the substantial building depths and the narrow courtyards, the facades in the courtyards are angled by 5 degrees so the sunrays can more easily reach the lower floors of the building. The light and matt facade cladding helps to distribute the daylight in the building.

Facade design In addition to its aesthetic function, the facade design plays a leading role in the overall daylight strategy of the building. The facades adapt to the urban context of the building and ensure the right balance between exterior solar protection and ample daylight in the office spaces. Interior solar protection prevents glaring for employees working by the screen.

Zoning In order for Munich to become part of Siemens and Siemens to become part of Munich, the majority of spaces at street level – both inside and outside – offer public access, just as a public passage runs across the building. The traditional employee cafeteria is transformed into a public restaurant.

Thermo-active constructions Siemens’ headquarters not only exploits the ability of concrete to store heat and cold. Water-bearing tubes are embedded in the concrete slabs and further reduce the energy consumption for heating and cooling.

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OPTIMISE :

131.6 kWh/m2/year

62.6 kWh/m2/year

Automation Electrical installations such as light and ventilation are automated and needs-based. This prevents the building from spending redundant resources on heating and at the same time minimise the risk of incorrect use.

LED Light The lighting is automatically controlled by daylight and motion sensors. In addition, all spaces of the headquarters feature LED lighting with a maximum energy consumption of 6-7 kWh/m2/year.

Mechanical ventilation A mechanical VAV (Variable Air Volume) ventilation system with state-of-the-art technology and highest possible efficiency is installed in the building. The system adjusts the air current to the actual need and is controlled by pressure sensors in the main tubes for injection and exhaustion, respectively.

PRODUCE :

62.6 kWh/m2/year

44.1 kWh/m2/year

Solar cell system A state-of-the-art solar cell system is installed on the roof of the building. The solar cells contribute to reducing the total energy consumption.

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The new Siemens headquarters is located in the centre of Munich. The ground floor is open to the public, and the courtyards are designed as an invitation for recreation or social interaction between employees and visitors. DESIGN WITH KNOWLEDGE |

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Social sustainability is weighed high in the master plan for Thomas B. Thriges Gade in Odense, Denmark. The planning of the public urban spaces and buildings centres on local commitment, health and mobility. 78 | DESIGN WITH KNOWLEDGE

6.1 Functional layout

Functional layout in the city Successful urban spaces attract new citizens and tourists and serve as a dynamo for the development of the city. The functional layout is an important element in achieving the urban dynamics that forms an essential part of economic and social sustainability. In these years, we are witnessing a historic urbanisation. Cities are rapidly expanding. One of the reasons for this trend is the many things that the city has to offer – a variety of job opportunities combined with a wide range of cultural experiences. A vibrant, dynamic city is ensured by a conscious functional layout where existing conditions are adjusted to new needs.

slightly different version of the same type of function.

It is about giving the city its own unique identity – on the outside and on the inside. On the outside, the city should stand out from other cities. On the inside, it should offer a multi-facetted, dynamic identity. Thus, infrastructure, green areas and functions should be distributed in accordance with the citizens’ use of the city.

The distribution of functions is an important factor in terms of exploiting the local climate. Daylight, wind and solar heat contribute to defining where functions should be situated. By basing the placement of functions on these climatic elements, the energy consumption of the buildings, which shape the city streets and plazas, is significantly reduced – as for instance passive solar heat can be used for heating dwellings. Thus, the identity and climate conditions of the city are reflected in the functional layout.

Every master plan project is unique because the setting – the neighbourhoods and existing infrastructure of the city – is determined in advance. If new functions are positioned in accordance with existing usage patterns, new city districts can change the dynamics of the entire city.

 very master plan project is unique E because the setting – the neighbourhoods and existing infrastructure of the city – is determined in advance.

Offices and cafes are not necessarily opposites. It can be beneficial to look at the segments who already use the city and – with this in mind – implement new functions that these segments will find useful.

In the city, the overall building geometries are often determined by district/city plans. This means that it is not always possible to achieve a fully energy-efficient building design. By incorporating the functions and future energy consumption of the individual buildings as well as the individual urban spaces, it is possible to achieve both sustainable cities and sustainable buildings.

The synergy between the various functions should be fully exploited – as a contrast to or as a DESIGN WITH KNOWLEDGE |

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6.1 Functional layout

Odense, Denmark 50,000 m2 Design year 2011

Case : Thomas B. Thriges Gade The master plan for the city district around the street Thomas B. Thriges Gade in Odense, Denmark, is based on the simple vision of transforming a heavy traffic thoroughfare into an attractive urban space. A vision of uniting the city across the trafficked street and re-establishing a consistent city centre in Odense. The competition proposal is based on five new urban ‘connections’ that will unite the city centre across the main thoroughfare of Thomas B. Thriges Gade, which has divided the city centre in two since the 1970's. The five connections each feature their own urban space that accentuates the character and function of the area by offering unique experiences and recreational qualities. The individual urban spaces thus contribute to creating a new strong identity for Odense city centre in the future. The project offers urban experiences at several levels and makes use of circles in the development of all plazas to create a dynamic, identity-creating and recognisable design. The round shapes are all different : some appear in the form of holes, hills or flat elements for people to sit on, lie on or lean against ; others create vibrant views up or down to the other levels.

Inspired by the use of bricks in many public spaces in Odense, all five urban spaces use different types, colours and patterns of bricks as basic pavement. Transport is a key element of the sustainability strategy for the project. As the objective for the master plan is a ‘zero cars policy‘, entirely new infrastructure is established, based on alternative communications. A light rail, an express bicycle track, a bicycle loop and a minibus are some of the communications introduced to get cars out of the city centre and put human activity back into focus.

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The divided city The establishment of the thoroughfare Thomas B. Thriges Gade in the 1960’s resulted in a separation of many functions and attractions in Odense. The city centre disappeared, and plazas such as Albani Torv – the original centre of the city – developed from being attractive urban spaces into a heavy traffic junction with no consideration for the individual citizen.

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Odense centrum med vigtige offentlige bygninger i dag opdelt af Thomas B. Thriges Gade.

Byen forbindes, så de to dele bliver éen.

The Park Connection The Cultural Connection The Plaza Connection The Street Connection The Church Connection

TEMAER

de to dele bliver éen.

De fem forbindelser tematiseres.

5 urban spaces/connections The five integrated urban spaces of the project centre on the existing cultural functions and attractions and bring these elements together. Crossroads now offer different kinds of activities and opportunities for random meetings.

De fem forbindelser tematiseres.

Light rail stop Light rail Steady development Express bicycle track City bus Bicycle route Banegårdsplads

Den Røde Løber

Kongens Have

H.C. Andersens Torv

Sortebrødre Torv

H.C. Andersens Plads

e

ad

erg

Ov

Infrastructure The master plan project gives Odense city centre back to the pedestrians. The new infrastructure with a light rail, express bicycle track, bicycle loop and minibus connect Odense city centre with the adjacent city districts and provide the basis for a sustainable city development. ade

erg

Fisketorvet

Ov

de

rga

Ove

I. Vilh. Werners Plads

Gråbrødre Plads

e

de rga ste VeFlakhaven

ad

terg

s Ve

ade

erg

st Ve

Albani Torv

Klingenberg

Banegårdsplads

01. INTEGREREDE RUTER Den Røde Løber Kongens Have

H.C. Andersens Torv

The 5 urban spaces Diversity The 5 connections The urban spaces between the buildings comprise Primary plaza 02. MANGFOLDIGE BYRUM 03. RUMDANNENDE BEBYGGELSE Secondary plaza a mixture of city functions, cultural activities and Landscape attractive dwellings of different types and sizes. Important buildings

In selected buildings, the ground floor has been allocated for public, extrovert activities. Together, the many different functions provide the foundation for a diverse city life.

Sortebrødre Torv

H.C. Andersens Plads

de

ga

UTER

ade

erg

Fisketorvet

Ov

de

rga

Ove

I. Vilh. Werners Plads

Gråbrødre Plads

de rga ste VeFlakhaven

Albani Torv

ade

erg

st Ve

Klingenberg

02. MANGFOLDIGE BYRUM

03. RUMDANNENDE BEBYGGELSE

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In the proposal for Carlsberg City District, the tower is designed with a view to deflect the wind away from walking and recreational zones. The faceted facade captures the daylight in different ways, providing the individual tower dwellings with daylight for a longer time. 82 | DESIGN WITH KNOWLEDGE

Carlsberg City District The Carlsberg district in Copenhagen is undergoing a transformation from industrial headquarters to vibrant urban space. In addition to the master plan for the area, the project includes educational buildings, residences and retail, cafes and commercial buildings. In the competition for Carlsberg City District, the task was to distribute a number of functions in a pre-defined building volume, including university college UCC, residences, retail, cafes and commercial functions. Daylight is an important element in the planning of the area to ensure optimal comfort for all functions. The lower floors connected to the plazas of the district are kept in dark colours that retain heat from the sun. The upper facades in bright colours open up the area and reflect sunlight into the urban spaces and opposite buildings. The buildings and urban spaces each have their own special character and are connected by streets, running as dense passages between the plazas.

the tower away from walking and residential zones. The facetted facade captures the daylight in various ways, providing the tower dwellings with ample daylight for a longer period of time. The overall concept has been to develop an urban district in human scale with a focus on attractive urban spaces, recreational zones, light, materiality and experiences. By working with ‘displacements’ in both plans and sections, the project creates a dynamic organism that offers varied building scales and dimensions as well as a rich variation of new and old, tall and low, deep and narrow, dark and light, open and dense.

The tower – which will stand out as a landmark for the area – is designed to deflect the wind around DESIGN WITH KNOWLEDGE |

83

6.1 Functional layout

Copenhagen, Denmark 80,000 m2 Design year 2011

Nedbrydning af volumen har direkte påvirkning af varme/ solstråling på Campuspladsen

Udgangspunkt for Masterplanen

Bearbejdet Masterplanen

Udgangspunkt for Masterplanen

Insolation Analysis

Bearbejdet Masterplanen Wh

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Contour Range: 240 - 1540 Wh In Steps of: 130 Wh

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890

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760

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1025 Wh

Solindstråling, kl. 08-18, gen. dagsværdier

Insolation Analysis Avg. Daily Radiation

Contour Range: 240 - 1540 Wh In Steps of: 130 Wh

10 Average Value: 538.60 Wh Visible Nodes: 3082

240

Wh

Wh

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1540+

1410

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1280

1280

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240

Solindstråling, kl. 08-18, gen. dagsværdier

10 Average Value: 538.60 Wh Visible Nodes: 3082

Geometry The project is based on a pre-defined building stock, as determined by the original master plan for Carlsberg. By cutting through and opening up the building stock, the daylight is allowed all the way into the deepest corners of the district. The variations in height create a vibrant, dynamic city district.

1025 Wh

Programming The original master plan is characterised by clusters of vertical, displaced volumes. However, instead of dividing the building stock into vertical functional units, the proposal for Carlsberg City District lays out the functions around university college UCC, which is situated at first floor level as a horizontal loggia that reflects the transition to and from the city plazas. This creates increased dynamics in the area all day long.

Daylight The geometric displacement of the building volumes allows the windows to open up to the sky and thus provides the interior spaces with ample daylight. The angled, broken facades also serve to refract light and provide an adventurous play of light during the course of the day. As part of the energy-optimising strategy, the project has focus on window sizes and orientation.

Materials The building facades are actively used to reflect and distribute daylight. All facades therefore have a dark base that becomes lighter as you go up. The light materials reflect daylight into street level. The dark materials absorb heat from the light and create a comfortable microclimate between the buildings.

84 | DESIGN WITH KNOWLEDGE | PROGRAMME DISTRIBUTION | CITY

The proposal for Carlsberg City District is based on state-of-the-art research on sustainability – both at building and master plan level. This knowledgebased approach has characterised the entire design process. DESIGN WITH KNOWLEDGE |

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Daylight is a free resource that adds value both economically and architecturally. It is a prime example of a design tool that embraces both soft measures and hard facts at the same time.

86 | DESIGN WITH KNOWLEDGE

7.0 Daylight

Daylight Daylight is a fundamental premise. Architecture is a balance between space and light, and daylight is the strongest means of creating value-based architecture. Daylight has a large influence on our health and comfort – and on energy consumption. When you work with light in an architectural context, you have to differentiate between sunlight and daylight. Sunlight is the simple factor of the equation. Sunlight that hits the ground surface can be divided into direct sunlight and diffuse sky radiation. The high intensity of sunlight creates large contrasts and a dynamic play of light on interior surfaces – but can also cause uncomfortable glaring and overheating. Diffuse sky radiation is the light registered on a cloudy day. It consists of light from the celestial sphere and the reflected light from outside surfaces. The luminance distribution of a cloudy sky is completely uniform – and the daylight provided on a cloudy sky is therefore often used to measure the light quality in a building. Diffused light does not depend on the orientation of the building. Reflected radiation can come from both sunlight and daylight. All surfaces hit by light rays will reflect a certain amount of light back into the space. The amount of reflected light depends on the angle of the surface in relation to the windows as well as on how shiny and bright the surface is.

cally, during the course of the day and the changing seasons ; it also changes from one minute to the next – both locally on the sky and locally in the interior space.

 aylight is a complex and very D dynamic entity. It is a free resource that creates value for a variety of parameters. Research clearly shows that daylight has a great potential. If it is incorporated into the energy strategy of a project and consciously exploited, daylight can add significant value in terms of comfort, health, energy and economy. Investments in daylight generate a large return in the form of considerable reductions in energy consumption and CO2 emissions. Energy consumption for artificial lighting is reduced in buildings with good daylight conditions. The area of use is expanded if the daylight is properly distributed across the building. Daylight is a free resource that creates value for a variety of parameters. It is a design tool that adds value for both the senses and the energy consumption.

Daylight is more complicated. It consists of three elements : direct radiation from the sun, diffuse sky radiation and reflected radiation from the ground and surroundings. Hence, daylight is a complex and very dynamic entity. It not only varies geographiDESIGN WITH KNOWLEDGE |

87

Umeå School of Architecture offers a simple, distinctive exterior expression and a dynamic, varied interior space. The three window sizes of the facade provide a wide variation of daylight – in terms of strength and direction – and make the building appear bright and welcoming. 88 | DESIGN WITH KNOWLEDGE

Case : Umeå School of Architecture Umeå School of Architecture has a unique location by Umeå River in the northern part of Sweden – only a few kilometres from the Arctic Circle. With its interior landscape of open levels and sculptural stairs, the building exudes creativity and artistic experimenting. As a growth centre for the architecture of the future, Umeå School of Architecture provides the framework for inspiration and innovation. From the outside, the building has a cubic expression, featuring larch facades and square windows placed in a vibrant, rhythmic pattern on all sides. The interior space is designed as a dynamic variation of stairs and displaced, open floors – where abstract, white boxes hang freely from the ceiling, filtering the light that pours into the space through the high skylights. One of the key objectives has been to create a bright and open study environment where everyone is part of the same room – yet separated by the displaced floors and the glass walls of the teaching rooms. The design thus supports the opportunity for mutual inspiration and facilitates the exchange of knowledge and ideas between the students.

In contrast to the dynamic atrium, the drawing rooms offer a simple, rational design. They are distributed along the facades in a strict, consistent sequence of columns and beams. The varied pattern of windows creates a strong visual effect and generously lets the light pour far into the building, while at the same time offering a breathtaking view of the passing river. Umeå School of Architecture has a highly transparent expression despite its opening angle of just 30 %. This owes to the three different window sizes and their distribution across the facade – which provides the building with ample daylight.

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7.0 Daylight

Umeå, Sweden 5,000 m2 Completed 2011

REFERENCE :

160 kWh/m2/year The project is based on Swedish standards for traditional building. This corresponds to 160 kWh/m2/year.

REDUCE :

160 kWh/m2/year

110 kWh/m2/year

Context Umeå School of Architecture is situated by Umeå River close to the city centre. Umeå is located just south of the Arctic Circle, which entails large seasonal fluctuations in temperature and daylight hours.

Position and orientation The School of Architecture is oriented parallel to the city structure, which consists of orthogonal squares. It has a separate location on the site but engages in close interaction with the new Art Museum and the Institute of Design.

Geometry The square, compact volume has a smooth exterior surface. The geometry examines and challenges how simple a facade can be structured, while at the same time maintaining a varied interior space.

90 | DESIGN WITH KNOWLEDGE | DAYLIGHT | BUILDING

Daylight The atrium and the increased floor height with 3.6 metres of clearance ensure ample daylight in all corners of the building. The interior atrium stands out in stark contrast to the exterior facade and appears as a light fitting in itself. The building has an average daylight factor (DF) of 3 %.

Facade design Three different window sizes have been applied in the facade design. The facade is perforated by 30 %, distributed across three window bands per floor. The three window sizes create great variation – on the lower floors, in the middle and on the upper floors.

Heavy structures In Umeå School of Architecture, the concrete slabs are exposed where possible in order to fully exploit the ability of concrete to store heat and cold. This prevents large fluctuations in temperature and thus improves the indoor air quality.

Materials The shell structure and the facade are primarily made up of pre-fabricated elements, which shortens and simplifies the construction phase. Sustainable materials have been used for the school. The building thus offers robust, maintenance-free products that will give the school a natural patina over time.

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OPTIMISE :

110 kWh/m2/year

100 kWh/m2/year

Ventilation The building is fitted with a mechanical ventilation system, featuring high-efficiency heat exchangers and heat recovery. The system has a central location in the building, which allows for shorter routing and fewer pipes.

PRODUCE :

100 kWh/m2/year No producing measures The ambition for the project was to create a sustainable educational institution based on long-lasting local materials, a minimum of surface treatment and reduced material consumption. This objective has been met solely by means of energy-reducing and optimising measures.

92 | DESIGN WITH KNOWLEDGE | DAYLIGHT | BUILDING

The open layout means that students and professors at Ume책 School of Architecture are all in the same room, only separated by the displaced levels. The open spaces are a source of inspiration.

DESIGN WITH KNOWLEDGE |

93

Campus Roskilde consists of four square buildings – slightly rotated in relation to each other so they form a curve. The displaced volumes contribute to optimising the overall energy consumption, while at the same time making the campus highly flexible in terms of future extensions. 94 | DESIGN WITH KNOWLEDGE

Case : Campus Roskilde With Campus Roskilde, University College Sealand consolidates its professional bachelor’s programmes in social education and social work, health and teaching. Situated adjacent to Roskilde University, the new campus will facilitate dialogue and random meetings between the students from the different study programmes and give them a feeling of being part of a united, diverse university environment beating with one pulse. Campus Roskilde consists of four square buildings covering a total of 20,000 m2. Slightly rotated in relation to each other, the buildings form a curve. On the inside of the curve facing Roskilde University, a roofed campus square creates life and a sense of community among the students.

sumption and make the campus flexible in terms of future extensions. With its high degree of flexibility and possibilities for cross-disciplinary activities, Campus Roskilde in many ways sets the tone for the study environment of the future.

At the same time, the buildings open up to the sun to fully benefit from the daylight during the course of the day. The displaced building volumes also serve to screen the campus from the motorway, just as they help to optimise the overall energy conDESIGN WITH KNOWLEDGE |

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7.0 Daylight

Roskilde, Denmark 20,000 m2 First phase inaugurated 2012

REFERENCE :

95 kWh/m2/year The project is based on the standards for traditional building as provided for in Danish building regulations BR08. This corresponds to an energy consumption of 95 kWh/m2/year. The objective for the project is to meet the energy requirements of BR08, corresponding to approx. 52 kWh/m2/year.

REDUCE :

95 kWh/m2/year

61.0 kWh/m2/year

Context Campus Roskilde’s interaction with the surrounding urban space of Trekroner and Roskilde University is an essential parameter now and in the future. Therefore, the building is based on the rectangular geometry of the master plan, and the access ways to the campus are made visible from the entrance to Roskilde University and the green avenue.

Position and orientation The large scale and long streets of Roskilde University need a higher degree of diversity and more intimate urban spaces. Campus Roskilde is placed at the site boundary to the north to create a more intimate space between the buildings and make the campus engage in interaction with the new student residences and a possible future extension. Campus Roskilde consists of four phases, four buildings – each of them based on the geometry of one of Roskilde University’s archetypes : the square. Geometri The first phase is the largest of the four buildings and thus the most important ‘square’. By rotating the three other buildings, the geometry is used to establish an effective screen towards the motorway and at the same time create a number of unique outside spaces towards Roskilde University.

96 | DESIGN WITH KNOWLEDGE | DAYLIGHT | BUILDING

Daylight All floors in the main building are naturally lit from atrium to facade, which creates transparency and a dynamic variation of light during the course of the day. By means of increased floor heights and glass walls in front of all teaching rooms and offices, the daylight is allowed into the far corners of the building. The atrium design places the largest, reflecting facades at the top in order to increase the amount of daylight on the atrium square. In the evening, Campus Roskilde will stand out with its bright, illuminated atrium.

Facade design The interaction with the surroundings as well as the high requirements for daylight have been key parameters in the facade design. The building features a tile facade to the south and a glass facade to the north. The southfacing, heavy facade primarily features deep windows that provide shade in the building and reduce traffic noise. The north facade design opens up the campus building towards Roskilde University.

Ventilation The general ventilation concept is based on mechanical ventilation in most of the building, supplemented with natural ventilation in the atrium. All rooms feature needs-based ventilation, which minimises operation and thus energy consumption. The building is fitted with high-efficiency ventilation systems featuring rotating exchangers as far possible. This makes the heat stay inside the building when needed.

Heavy structures Campus Roskilde is based on a concrete structure. Together with the south-facing, heavy facades, this results in a building with a substantial thermal mass. This again contributes to reduce fluctuations in temperature and minimises the risk of overheating – just as the need for heating and cooling is reduced significantly.

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OPTIMISE :

61.0 kWh/m2/year

48.7 kWh/m2/year

Mechanical ventilation Campus Roskilde applies a well-known ventilation concept. According to studies of a highly exposed teaching room to the south, among others, the ventilation concept ensures an optimal indoor air quality with very few hours above the tolerance values. The studies also show that the temperature in the teaching room only exceeds 25 °C in eight hours a year during school hours and never exceeds 26 °C. This is much better than normal.

Lighting High-efficiency, low-energy lighting featuring daylight sensors has been installed in the building, which ensures a minimum of 350 lux in all rooms at all times. The energy consumption for lighting is kept at 10 W/m2 despite the high lux value. This ensures a very low energy consumption for lighting.

PRODUCE :

48.7 kWh/m2/year

No producing measures The ambition for the project was to meet the standards of Danish building regulations BR08, corresponding to approx. 52 kWh/m2/year. This objective has been met solely by means of energy-reducing and optimising measures.

98 | DESIGN WITH KNOWLEDGE | DAYLIGHT | BUILDING

The design of the atrium contributes to increasing the amount of daylight on the square. By means of high floors and glass in front of teaching rooms and offices, the daylight is allowed far into the various floors of the building. DESIGN WITH KNOWLEDGE |

99

Reflectance can be used to increase the quantity and quality of daylight in the city. A matt surface diffuses and distributes daylight to the surroundings. A bright facade only reflects daylight in one point.

100 | DESIGN WITH KNOWLEDGE

7.1 Daylight

Daylight in the city Daylight has a significant influence on our health and comfort. How large a sustainable gain can we achieve by using daylight as the only means of revitalising the city, the building and the dwelling ? Cities transform slowly while individual buildings change at a faster pace. Therefore, decisions made in urban planning impact several generations, and urban planners have decisive influence on the development of sustainable cities. Dispersed cities have a very high energy consumption for transport. Dense cities are much more resource-efficient but they make it more challenging to ensure environmental and experiential qualities, ample sunlight and daylight for users and residents. High-density cities and optimised distribution of sunlight and daylight constitute two conflicting entities that need to be balanced. The form, density and organisation of the city have a substantial influence on the amount of sunlight and daylight. The energy consumption of the individual building is directly influenced by these factors. For instance, the orientation of streets determines when and the degree to which the sun reaches street level and pours into the buildings. Therefore, the approach to developing the urban spaces of a city is the first step to ensure the best possible distribution of sun and daylight. The streets’ orientation relative to the points of the compass impacts the distribution of daylight and solar energy. In a street system oriented due north-south, half of the streets will have sun for most of the day, while the other half will be in shade.

Urban structures with a diagonal orientation in relation to the points of the compass allow the sun to pour deeper into the urban space, thus also providing more interior spaces with light in the darkest months of the year. For instance, the sun will have a better chance of pouring deeper into low-lying flats at the time of the day when most activity takes place – in the morning and in the evening.

High-density cities and optimised distribution of sunlight and daylight constitute two conflicting entities that need to be balanced. Both experientially and environmentally, daylight is one of the most important parameters in building design and should be considered a common resource in urban planning : Urban planners should incorporate this aspect and acknowledge the possible energy-related synergies between the various elements and typologies of the city. Buildings can create better conditions for each other in relation to sun, shadow and wind. Hence, optimising the city structure is a necessary prerequisite for reducing the energy consumption of the individual buildings.

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7.1 Daylight

Copenhagen, Denmark 150,000 m2 Development project completed 2012

Case : Nørrebro City District The development project based on a specific residential quarter in Nørrebro city district, Copenhagen, aims to inspire for improved cities and dwellings through optimisation of existing daylight conditions. Daylight is the strongest means of change in the renovation, modernisation and transformation of our cities and buildings. Daylight is scalable and is a precondition for architecture and buildings. You can and should work with daylight in all types of building projects all over the world. The approach to urban planning is the first element in a series of decisions that can optimise the distribution of sun and daylight in the city. The form, density and organisation of the city impact the access to daylight and have a large influence on the energy consumption of the individual building. However, buildings change faster than cities. Some buildings remain for a long time ; others are torn down entirely or partly when they are not longer assessed valuable. Facades are regularly modified over time and surfaces are painted, plastered or 102 | DESIGN WITH KNOWLEDGE | DAYLIGHT | CITY

cleaned. In daylight renovation, the building thus constitutes the second element – after the overall city structure – in the decision-making process. The building spaces change as new residents move in and as people’s needs change. Our home and workplace are the primary settings for our everyday life – and thus the end objective for architecture. The specific development project in Nørrebro city district, Copenhagen, has isolated daylight as a key parameter with a view to make the available knowledge on daylight and architecture applicable. The project has resulted in a manual – a kind of ‘toolbox’ – offering a number of tools that all create added value in the overall sustainability accounts.

D

ys sl ag er r kr e si sikr gå by gs e

A B

Daylight in the city The urban structure of the selected residential quarter in Nørrebro city district, Copenhagen, has a diagonal orientation relative to the points of the compass. This allows the sunlight to pour deeper into the streets and be an active asset to city life in the outdoor season. Solar studies serve to disclose the quality of the urban spaces and the potential for using the sun as energy source.

A

at ligger

B

es de og forrhold gn vil uelle

C

tisk ninger, e muomgivrne, hold ger.

D

ehageelukategier

A B B C

D

ehageeriode; elukategier

re;

D A B

signumdagslys sikrer å sikrer bebyg-

Daylight in the building block The majority of flats in the selected building block has access to direct sunlight. The solar diagram shows how the top floors are provided with the largest amount of daylight while less daylight is allowed into the lower floors. This is primarily due to shadow from the opposite buildings.

C

at ligger signumdagslys es de sikrer og å sikrer forbebygrhold gn vil uelle fra 4 dgange klasstisk lysnivninger, e muomgivrne, hold ller liggende; v.ger.

A

fra 4 dgange klasslysniv-

Daylight in the building By working with building geometry, including form and reflection, the daylight can be optimised according to the use patterns of the individual flats. For instance, reflected daylight from an angled facade can be exploited to optimise the amount of daylight in the morning and evening hours.

ller liggende;

C

v.

eriode;

re;

D

Daylight in the dwelling By mounting larger windows with energy-efficient glazing, the energy consumption can be reduced and the daylight level increased without re-insulation. This increases the amount of daylight in the dwelling by 34 % and reduces the energy consumption by 37 %.

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The master plan for Thomas B. Thriges Gade in Odense, Denmark, is based on five new urban spaces, organised around each their own urban ‘connection’ : The Park Connection ; the Cultural Connection ; the Plaza Connection ; the Street Connection and the Church Connection – where Albani Torv, on which the church is situated, is re-established as the cen104 | DESIGN KNOWLEDGE tral plaza WITH in the city.

Case : Thomas B. Thriges Gade The competition proposal for the master plan of Thomas B. Thriges Gade creates a new ‘breathable’ city centre in Odense, Denmark. Based on a CO2 neutral and Integrated Design strategy, the project is a showpiece for sustainable urban planning. Since 1970, the four-lane street of Thomas B. Thriges Gade has divided Odense city centre in two. The competition proposal diverts traffic to close the cut through the city centre and allow a new, coherent city district to take shape. With a new light rail and a ring road around the city, the city centre will be free from cars – and human activity is put back into focus. The competition brief requires a high-density city centre, with a building stock increase of 50-70,000 m2. Studies of the adjacent context and Odense as a city show that the buildings have an average height of 3-5 storeys and the streets an average width of 10-15 metres, corresponding to a ratio of approximately 1 :1. These numbers are used in the densification of the city centre and provide the basis for the new building structure. In order to meet the requirements, the density of the building

stock is increased, while the daylight is exploited to create functional, healthy buildings and attractive urban spaces. Being CO2 neutral, the city centre stands out as a showpiece for sustainable urban development. The competition proposal is based on a holistic approach to sustainability where human life quality is the overall and most important aspect.

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7.1 Daylight

Odense, Denmark 50,000 m2 Design year 2011

1

1

ØST

Further densification It is not possible to achieve the required plot ratio within the premises of the 1:1 strategy. Therefore, the density of the building stock is further increased by establishing towers to the north-west. This minimises the level of shadow on existing and new buildings.

>>

Gade

U=0,1 U=0,9 tlægpassiv

Densification The competition aims to add 50,000 m2 to the city district. Analyses of the existing density in Odense has inspired for basing the urban development on a 1 :1 strategy where the height of one building corresponds to the distance to the next building. This ensures that the amount of daylight in all existing dwellings is reduced by a maximum of 20 %.

VENTILATION - Behovstyret ventilation med varmegenvinding (90%) og høj nyttevirkning (SEL=1,0)

Urban space design The orientation of the primary spaces of the master plan is based on the sun and the function of the individual space. This ensures an optimised outdoor climate in each of the urban spaces. The plaza of H.C. Andersens Plads – a popular place for tourists to visit in the morning – thus opens up to the south-east.

Functional layout A conscious functional layout is another important aspect of the sustainability strategy. Commercial functions are situated with a view to minimise their exposure to the sun – as these functions often consume a lot of energy for cooling in order to obtain a comfortable indoor air quality. On the other hand, the position of the dwellings allows ample light to pour into the spaces in the afternoon and evening hours.

og

f gen

FUNKTIONSDISPONERING - Optimal placering af funktioner og arbejdspladser 106 | DESIGN WITH KNOWLEDGE | DAYLIGHT i| forhold CITY til orientering - Smart grid bygning - intel-

FACADEDESIGN - Maks. vinduesprocent 30-50% (erhverv) - Maks. vinduesprocent 20-40% (bolig)

In the new master plan, all parking facilities are placed underground in order to fully exploit the ground area. Offering ample daylight and green plants, the underground parking facilities appear light and welcoming. DESIGN WITH KNOWLEDGE |

107

Spiegel’s new headquarters in Hamburg, Germany, features German natural stone on the entire ground floor. Up to first floor level, both floors and walls are clad in this local material whose bright colour appears in stark contrast to the dark, outdoor paving. 108 | DESIGN WITH KNOWLEDGE

8.0 Materials

Materials The selection of materials contributes to defining the indoor air quality and comfort. However, materials reach beyond the life span of the building and have an important social, economic and environmental influence. Buildings breathe just as humans. A building can be compared to a lung where the materials constitute the tissue. During the life span of a building, the materials contribute to defining the indoor air quality. We spend most of our day indoors. Therefore, it is essential that building materials have a positive influence on the indoor air quality – and thus our health and comfort.

If the indoor air quality is poor, productivity falls. Indoor air quality is an important item on the agenda in planning and building projects. Selecting the right materials optimises the air quality, acoustics and fire precautions. Likewise, operation and maintenance are important aspects to take into account in terms of building economy. It must be easy to make healthy choices. The indoor air quality is one of the most influential aspects in a building. If the indoor air quality is poor, it can result in headache, discomfort and reduced efficiency. Research shows that indoor air quality has a great impact on work efficiency. If the indoor air quality is poor, productivity falls. Degasification from materials can be one of the reasons for this. If the degasification from materials exceeds recommendations, the atmospheric indoor air quality decreases, which

can ultimately lead to respiratory diseases and allergies. The acoustic indoor climate is also decisive for the general feeling of comfort in a building. Acoustics can be regulated by means of materials so even large rooms do not become acoustic ‘pitfalls’ but are functional and comfortable to stay in. The risk of fire has a direct connection to the selection of materials. This not only applies to surface materials but also to construction materials and installations. Materials must be assessed based on the risk of self-ignition, fire behaviour and smoke formation. Material selection is about transforming the design concept into practice, and the architectural vision is reflected in the level of detail and craftsmanship of the building. Users get the full experience of a building when they feel that there is a meaning behind the various elements – that they are connected from the largest structure to the smallest detail. The selection of materials is a very specific and clear signal of the building’s and client’s approach to sustainability. A careful material selection results in both healthy buildings and healthy users.

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8.0 Materials

Hamburg, Germany 50,000 m2 Completed 2011

Case : Spiegel Headquarters The new headquarters for Der Spiegel Group in Hamburg, Germany, consolidates the different media of the organisation. Meeting the highest sustainability requirements for buildings in Germany, the headquarters is certified for a gold medal in the certification system of HafenCity. The headquarters consists of two large glass volumes placed on a shared, sculptural tile base. The base opens into a broad plinth towards the harbour and creates a large public plaza between the buildings. The large glass facades open up to a new park to the south and the central station of Hamburg to the north. The large, central window of the building generates an active dialogue between the vibrant activities of the media group and city life. As particularly distinctive features, you find the three-storey high café lounge and the 13 footbridges in the atrium, which establish a vertical connection between the third and twelfth floor. In the selection of materials and furniture for the buildings, all products and materials have been carefully examined. Materials containing PVC or 110 | DESIGN WITH KNOWLEDGE | MATERIALS | BUILDING

other black-listed substances have been avoided. All products have been evaluated on the basis of their performance to ensure a good indoor air quality – just as they have been tested in terms of how easy they are to clean out of consideration for allergists. All in all, these factors have been determining for the new headquarters obtaining the eco-label ‘Gold’ in the certification system ’HafenCity Umweltzeichen’ in June 2012. The local certification system of HafenCity contributes to giving the newly developed harbour area its own unique identity just as it serves to spearhead the development of sustainable building in Germany.

Certification Spiegel’s new headquarters is Henning Larsen Architects’ first certified project in Germany. Intense efforts have been put into meeting the strict environmental and health requirements of ‘HafenCity Umweltzeichen’, including aspects such as acoustics, indoor air quality and environmentally friendly operation. Thus, the material selection has included careful considerations regarding operation and maintenance.

Contrasts The design of Spiegel Headquarters is based on contrasts. By the entrance, the colourful outdoor paving meets the bright interior – creating a beautiful contrast between the dark, rough exterior and the light, smooth interior. The overall colour concept has a strong Scandinavian touch ; the large spaces appear in bright colours, with contrasting highlights of vivid colour in selected places of the building.

Materials Only FSC certified wood has been used in the building. Wood has a warm expression and establishes a direct connection to nature and the overall green strategy applied in the building. German oak wood and German natural stone have been used for the interior in order to minimise resources for transport and root the building in the local context.

Transparency The headquarters reflects the values of Spiegel as an open, modern media house. The building is highly transparent, which is an important point of the concept design – that Spiegel’s employees have direct visual contact to the city and the world they are writing about. In the same way, citizens and tourists get an insight into the everyday work of the large media group.

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Spiegel’s headquarters is designed as a transparent volume, elegantly floating above a solid base of red tiles. The materials for the building have been selected on the basis of their performance in order to create a good indoor air quality. 112 | DESIGN WITH KNOWLEDGE

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Healthy, long-lasting materials have formed an important part of the sustainable strategy for Novo Nordisk Corporate Centre, which is based on Novo Nordisk’s own Triple Bottom Line concept : Environmentally Sound, Economically Viable and Socially Responsible. 114 | DESIGN WITH KNOWLEDGE

Case : Novo Nordisk Corporate Centre The ambition for Novo Nordisk Corporate Centre has been to develop a building that protects the environment and the people working in the building, under and after construction. Novo Nordisk’s new corporate centre in Bagsværd on the outskirts of Copenhagen will be the workplace of the company’s top management and 1,100 administrative employees. The building offers a simple, distinctive expression and provides optimal work conditions with its functional, sustainable design. In order to avoid long transport, primarily Scandinavian and North European materials have been selected for the building. Only resource-efficient materials with a low environmental impact have been applied – and, as far possible, materials that are toxic during processing or in use have been avoided. With this strategy, the building meets the requirements of the next best category in Danish indoor air quality standards (DS15251), ‘low-polluting materials’.

As something entirely new in Denmark, silicate paint has been used for the interior part of the building to reduce degasification. In addition, architects and engineers have worked closely together to develop a special ceiling type for the building that supports a new ventilation system called displacement ventilation. The linear ribbed ceilings let fresh air seep slowly into the entire space. This results in a particularly good air exchange just as draught from the ventilation shafts is avoided. In the selection process, social, economic and environmental issues relating to the production of materials have been carefully considered to ensure a material selection that supports the Triple Bottom Line concept of Novo Nordisk, which forms part of the company’s strategy for Corporate Social Responsibility (CSR).

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8.0 Materials

Bagsværd, Denmark 50,000 m2 Under construction

Indoor air quality The materials in Novo Nordisk Corporate Centre plays a significant role in relation to the indoor air quality of the building, which meets the second highest category in Danish indoor air quality standards. Silicate paint has been applied on all walls and surfaces, which reduces degasification. This type of paint has not previously been applied on the interior of large-scale buildings in Denmark.

Acoustics The circular geometry is broken by a variety of rooms and niches, which provide a good sound distribution. This prevents sound focusing as often experienced in circular spaces. All ceilings have good acoustic properties and the balcony edges feature a special acoustic plaster finish. In the open plan offices, the sound-absorbing walls are made up of perforated gypsum boards.

Ceilings Novo Nordisk Corporate Centre features a special ceiling, based on a new ventilation system in Denmark – displacement ventilation – which is optimised in relation to draught and minimises the need for ventilation ducts. This results in extraordinarily low energy consumption for ventilation, low installation costs and good air exchange.

Floors Due to often poor acoustics in open plan offices, the floors are primarily covered with carpets. All carpets are eco-labelled according to Danish indoor air quality standards. One of the building levels features a wooden floor, which gives a Nordic expression. FSC and PEFC certified Kebony pinewood has been used for the outdoor terraces and park.

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The material selection for Novo Nordisk Corporate Centre contributes to creating a very good indoor air quality. A custom-designed ceiling and ventilation system minimises draught and ensures a steady room temperature. DESIGN WITH KNOWLEDGE |

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Reflected light is an interesting parameter in all city scales – master plan, building block and dwelling – as any surface reflects a certain amount of the light that hits it. Thus, there is a great potential in looking at surface materials in the optimisation of daylight quality. 118 | DESIGN WITH KNOWLEDGE

8.1 Materials

Materials in the city The urban microclimate is defined as soon as in the design phase when facade materials are selected. The quantity of daylight is determined by the reflectance of surfaces and the amount of daylight they generate to urban spaces and other buildings. Material selection is not only a question of comfort for the users of the building. Comfort for the users of the urban space should also be taken into consideration. Building facades interact with the climate conditions and contribute to creating local climate zones of warmer and steadier temperatures. To achieve optimal climate zones, facade materials must be carefully selected. Materials are an active co-player in the development of good daylight and thermal conditions. They are of decisive importance in terms of avoiding higher temperatures in the city compared to outside the city.

If materials are selected on the basis of their ability to reflect light, it is possible to create good daylight conditions even in dense cities. Obtaining optimal daylight conditions in the city is a balancing act that requires careful attention to the compactness of buildings. The wish for dense cities is based on the wish to reduce energy consumption. However, dense city structures can have a negative impact on the amount of daylight. A careful material selection can make daylight and density work together rather than against each other.

gain for the microclimate. Taking this approach, the buildings become ‘daylight fittings’ in the urban space. PhD Jakob Strømann Andersen’s research shows that the daylight level in a city can be increased by 30 % by introducing light plaster facades. The precondition for successful urban spaces in the latitudes of Denmark is good air quality. Warm, sunny spots are preferred to cold, humid spaces. Dark materials with rough surfaces retain heat even when the sun is gone. This extends the use of the urban space. Heat absorption is a general problem. Cities accumulate heat, which has to be ventilated away from the urban spaces. The phenomenon of overheated cities is referred to as ‘urban heat island’. The ability of light materials to reflect solar heat can be used as an active strategy to avoid heat accumulation and is thus a key to reduce the heat impact. In the same way, trees and plants can be used to create a ‘cool island effect’. Plants retain humidity and create shadow and oxygen – all important elements in ensuring a good, steady microclimate. Fluctuations in temperature are common near plazas and parks. Here, temperatures can be reduced by up to three degrees, solely by means of vegetation.

If materials are selected on the basis of their ability to reflect light, it is possible to create good daylight conditions even in dense cities – which is a real DESIGN WITH KNOWLEDGE |

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Copenhagen, Denmark 150,000 m2 Development project completed 2012

Case : Nørrebro City District The amount of daylight in an interior space or in an urban space not only depends on the directly accessible daylight but also on the light reflected by the surfaces. Reflectance is the keyword when dealing with daylight in sustainable building. Daylight is a complex entity. It covers a variety of different factors that together provide a fantastic effect. When you talk about light, you thus have to distinguish between quantity and quality. How much – and how good ? The development project ‘What about daylight?’ examines the significance of daylight by means of a case study in Nørrebro city district, Copenhagen. The quality generated by daylight is studied at three levels : at master plan level, at building level and at dwelling level. Any surface reflects a certain proportion of the light that hits it. Therefore, the reflective properties of surfaces around windows as well as the surroundings – for instance opposite facades – are essential for the daylight quality in a dwelling. In addition, bright facades with high reflectance can be used to 120 | DESIGN WITH KNOWLEDGE | MATERIALS | CITY

increase the daylight level in dense city structures. In this development project, the daylight factor in itself does not demonstrate great variation – but if sunlight is incorporated, the reflectance of the bright facades significantly contributes to increasing the amount of daylight. This is of particular benefit to the lower floors of a building block. Summed up, reflected light is an interesting parameter in all three scales – master plan, building block and dwelling. How does light move through urban spaces and interior spaces depending on the urban geometry and materials? Is there a potential in looking at surface materials in relation to optimising the quality of daylight? Studies from Hong Kong show that reflected daylight can serve as the main source of natural light in dense, highly populated cities.

Sollys Himmellys

Daylight incidence The quantity of daylight in a building or an urban space depends on the reflectance of surface materials, the incidence angle of light in relation to the surface and the angle of the surface itself. The daylight factor describes the relationship between daylight on the inside and on the outside and is used to determine the need for daylight in a building.

Reflektion

Dagslys og varmeudledning

Reflected daylight Any surface reflects a certain amount of the light that hits it. Therefore, the reflectance of the surface around a window as well as the surroundings – for instance the opposite facades – are decisive for the overall quantity of daylight.

Reflectance Daylight is made up of direct radiation from the sun, diffuse sky radiation and reflected radiation from the ground and surroundings. The reflected radiation can stem from both sunlight and daylight. The reflected light depends on the surface angle in relation to the light incidence and on how shiny and bright the surface is.

+ Reflekteret lys

Surface treatment The ability of a surface to reflect light depends on its finish. A shiny surface reflects more light than a matt surface. However, as the shiny surface only reflects the light in one point, the light is also returned to one point, in the same angle as it was reflected. On a matt surface, the light has a more diffuse reflection, which provides the surroundings with more light. DESIGN WITH KNOWLEDGE |

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Riyadh, Saudi Arabia 1,600,000 m2 Under construction

Case: King Abdullah Financial District  

The facade provides a first impression of the distinct qualities of a building as well as its significance for the city as a whole. In King Abdullah Financial District in Riyadh, Saudi Arabia, a manual for design and sustainability ensures the quality of the new district. The 1.6 km2 new financial district in Riyadh provides the foundation for a sustainable, diverse urban development where functionality, accessibility and architecture form a whole. It will take many years before the new financial district is fully built-up. To ensure a diverse urban development of high architectural quality and an ambitious focus on sustainability, a design and materials manual has been prepared. The manual looks into four different parameters in terms of facade design : Materials, colours, transparency and shadow effect. Applying bright, high quality materials contributes to ensuring internal harmony between the buildings of the financial district. Light surfaces absorb less sunlight and thus reduce the risk of overheating inside the buildings. 122 | DESIGN WITH KNOWLEDGE | MATERIALS | CITY

Transparency largely influences the amount of daylight in a building – and is likewise an important means of creating a dynamic, vibrant city. In general, facades should provide shade from the sun and thus reduce the risk of overheating in the interior spaces. Shade should be incorporated as a key parameter in the early design phases and thus be integrated into the building design from the beginning.

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The use and special requirements for each building will influence the architecture of the facades. The DMG takes into careful consideration how public and retail areas impact the facades. The DMG describes special requirements for the transparency of the facades in areas where facades should be open and welcoming in order to create a vibrant city.

Materials and colours are naturally integrated parts of the facade architecture. As each facade contributes to the overall context the DMG suggests creating a balance between colours and materials.

The facades should all be treated different from one another. Some should even be treated differently in both shape and materials. Architectural treatment of buildings includes form, materials, colours, transparency and shading and should be varied in respect to orientation to enhance energy saving opportunities. The DMG provides information on these issues. A sustainable design approach towards ecological balances and green architecture is encouraged.

Facades give you the first impression of a building. The facades expose the unique of the particular building as well as being part of a larger context with the neighbouring building facades in the cityscape. You are able to see the facades from a plane or helicopter, passing by in high speed in a car or arriving by foot. All scales should be taken into careful consideration in the architectural process in order to create an impressive and well-functioning city.

2.1 VISION FACADES

LOWER LEVEL

Materials Bright materials should be applied in areas that are particularly exposed to overheating. Highly reflective facades such as mirror or glass facades should be avoided to prevent glaring. Local quality materials should be applied to the highest degree possible.

Fig. 02.01 | Facade partiton elevation

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During the planning, realisation and construction each new building in KAFD should contribute to this vision.

As the facades shape the perceptions of the building and its context they also serve the crucial function of a building providing shelter from weather and climate. The specific geographic conditions in Riyadh require special consideration in order to make shade on the facades and when selecting materials for the facades. The DMG describes several recommended options to obtain sustainable solutions.

Facade | Cul de Sac

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Fig. 02.02 | Plan | All facades

Categories In the design manual, the building facades are divided into eight different categories, depending on the location of the building within the master plan. For each category, the manual offers guidelines for materials, colours, transparency and shade. The different facades of the same building can feature in several categories.

Transparency Transparent facades should be selected at street level where they create a sense of safety and add a positive dimension to city life. The facade transparency above street level should be adapted to the function and orientation of the building. Here, translucent materials can be sufficient.

Solar protection The facades are fitted with effective solar protection. Exterior solar protection should be adapted to the local context and be able to withstand local wind and weather conditions, and maintenance of technical installations should be carefully considered. In order to ensure a good indoor air quality in all buildings, solar protection should form an integral part of the individual building.

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Building materials play a central role in the development of King Abdullah Financial District. In a climate where the sun is at its highest intensity in daytime, it is crucial to apply materials that cool down and provide shade for the urban spaces and thus ensure a comfortable microclimate. 124 | DESIGN WITH KNOWLEDGE

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The dissemination of new knowledge is decisive to reduce the gap between research and practice. Courses, lectures and cross-disciplinary development or research projects are good means of communicating knowledge to a broader audience. 126 | DESIGN WITH KNOWLEDGE

9.0 New roles

New roles, new opportunities New knowledge provides new opportunities for changing ingrained habits and traditional ways of thinking. Architects already work together with a wide range of professions in the development of projects. This cross-disciplinary collaboration should be expanded further. Traditionally, architects work alone in the early phases of design. The first sketches are made by the architect without interference by others. Not until a long way into the process, when the creative concept is almost determined, the engineers are involved in the project.

design process. It should be disseminated to the rest of the world. The employees of the Sustainability Department at Henning Larsen Architects give lectures, speak at conferences, write articles and participate in development projects, think tanks and other related activities.

As the preconditions for the energy consumption of a building are partly defined by the urban/landscape context and partly by the basic parameters of the design – as described in the previous chapters – the logical consequence is that architects and engineers should work closer together at an early stage of the design process.

Research results cannot always be applied in the design process as they are. Most often, they need to be adapted and transformed into a format that makes them applicable. By connecting new research results with knowledge generated in developments projects with a more narrow focus, you achieve an application-oriented design tool. Focus can be on an individual project – where a number of sustainable objectives are formulated – or it can be on cross-disciplinary collaborations – where a building material, a typology or a digital tool is developed. This approach creates innovation.

Therefore, it is also natural that architects contribute to build and activate new knowledge. Acknowledging that the best results in sustainable building are achieved when the design itself is based on a scientific foundation qualifies the work in sustainable architecture. Architects should work in more open processes, and engineers should be willing to contribute in creative processes that are not as strictly methodological as they are used to.

Research results should be applied to add value. It is essential to bridge the gap between research and its practical significance and use. The following pages present a selection of the development projects that Henning Larsen Architects is engaged in.

Therefore, it is also natural that architects contribute to build and activate new knowledge. Research should pro-actively be brought into play in the everyday work. It should form an integral part of the DESIGN WITH KNOWLEDGE |

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128 | DESIGN WITH KNOWLEDGE | NEW ROLES | A+E :3D

9.0 New roles

A+E:3D A+E:3D is a digital tool that makes it easy for architects to calculate the energy consumption of different designs in the early concept development. These calculations provide a good foundation for a dialogue on energy-optimisation with clients and engineers. A+E :3D is an analysis and dialogue tool for managing the various parameters in building geometry that have an impact on the overall energy consumption. The tool is very useful in the early design phases where it helps to develop energy-optimised concepts for new buildings and conversions.

A+E :3D ensures both a high architectural quality and a low energy consumption from the early concept design.  The programme is developed for architects with a view to allow them – in collaboration with engineers and clients – to make fast, interactive 3D energy calculations of different geometric and design concepts, as part of a strategic energy-optimisation in the early stages of design.

windows, standard windows or sun protected windows.  +E :3D ensures both a high architectural quality A and a low energy consumption from the early concept design. A+E :3D can be downloaded at www.apluse.dk (only available in Danish). Project development team   VGLCPH The Danish Building Research Institute Henning Larsen Architects Esbensen Consulting Engineers InteractiveLabProduction The project is supported by ELFORSK under the Danish Energy Association.

There is a high demand for a digital tool of this kind as existing programmes in the field are primarily developed for engineers and used in the detailed design phase, that is, at a late stage of design. The innovative functions of A+E  :3D allow the user to test complex volume models in relation to Danish building law already in the early stages of design. No other similar tool has this possibility. A+E :3D offers an intuitive, visual user interface. As a result of its simple calculation parameters, the user only has to enter a fixed set of values – e.g. whether the building features daylight-optimised DESIGN WITH KNOWLEDGE |

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130 | DESIGN WITH KNOWLEDGE | NEW ROLES | ENERGIMÅL.DK

9.0 New roles

Energimål.dk Energimål.dk is a new, digital tool that works as an expanded calculator. It provides specific suggestions for how to approach energy renovation of large-scale commercial properties by automatically drawing on publicly accessible building data. Energimål.dk provides the user with fast and easily accessible recommendations for the energy renovation approach that offers most added value. The recommendations are based on the specific building data entered by the user. Energimål.dk offers advice on architecture, economy and technical installations with a view to save energy and make it easier to establish a common starting point across the various professional fields.

 he tool optimises the decision T process prior to the renovation. Currently, there is a lack of overview and knowledge of technical installations that reduce the energy consumption and CO2 emissions of existing buildings – and at the same time take architecture and economy into account.

energy labelling database of the Danish Energy Agency. Energimål.dk was launched in June 2012. Project owners  The Danish Property Agency Albertslund Municipality DATEA A/S Project consultants Esbensen Consulting Engineers Henning Larsen Architects NHL Data ApS Energimål.dk has been developed with support from the Realdania Foundation.

The primary objective of Energimål.dk is to bridge the gap between technical know-how on energyoptimising installations on the one side and calculations of the viability of the investment as well as the operational savings after completion on the other. The tool optimises the decision process prior to the renovation. Additionally, it is able to point out possible energy savings in a project that had only been considered as normal maintenance work. Energimål.dk draws on real property data from the DESIGN WITH KNOWLEDGE |

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132 | DESIGN WITH KNOWLEDGE | NEW ROLES | WHAT ABOUT DAYLIGHT ?

9.0 New roles

What about Daylight ? The development project ‘What about daylight?’ examines daylight as an isolated parameter in renovation projects. The project describes the history and value of light and provides specific strategies for how to optimise the quality of daylight in dense cities. Everyone loves daylight. However, knowledge on daylight is difficult to apply in practice because light is assessed both quantitatively and qualitatively. ‘What about daylight’ transforms specialised knowledge on daylight from engineering calculations and architectural poetry into an intelligible language with a valuable content. Building value is about much more than technical structures, materials and energy. It is also about the activity that takes place in the building, about human relations and about safety. It is about market prices and architectural quality. When dealing with building value, we must take a holistic approach and incorporate the entire building, not only the value of the individual components.

There are no limits to light. It can be optimised in the complex context of the city, in the specific building or in the individual dwelling.

city district in Copenhagen as an example – because this is where daylight has the poorest conditions and because the structure of the building blocks in Copenhagen is well-known, not only in Scandinavia but all over Europe. Even though you do not live in a building block in Copenhagen, the knowledge of the manual is highly useful. There are no limits to light. It can be optimised in the complex context of the city, in the specific building or in the individual dwelling. Project development team  Henning Larsen Architects Charlotte Algreen, Algreen Architects Peter Andreas Sattrup, PhD, Associate Professor, DTU Civil Engineering The project is supported by the Realdania Foundation.

‘What about daylight’ considers daylight as the new key parameter in complete renovations, both qualitatively and quantitatively. The aim is for the dynamic, invigorating properties of daylight to serve as a connecting link between the goals, means and results of the renovation. The strong relation and synergy between daylight, health, energy and architecture form the backbone of the project. The study is based on the dense city – taking Nørrebro DESIGN WITH KNOWLEDGE |

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134 | DESIGN WITH KNOWLEDGE | NEW ROLES | MULTI-FUNCTIONAL CONCRETE

9.0 New roles

Multi-functional concrete The development project ‘Multi-functional concrete structures for new buildings and renovation projects’ aims to develop technologies which improve the thermal storage capacity of concrete, that is, the ability of concrete to retain heat or cold. Since 2009, the cross-disciplinary development project has examined a variety of sustainable materials, with a particular focus on concrete. The project has looked into the opportunities for exploiting the thermal potential of concrete with a view to create a good, steadier indoor air quality – both thermally and acoustically – as well as reduce energy consumption and CO2 emissions both in construction and in operation. A central element in the project has been laboratory tests where different types of concrete with optimised heat storage capacity have been examined. For instance, the tests have looked into concrete of increased density (rho+) as well as concrete offering high thermal conductivity (lambda+). The different concrete types have been tested in EnergyFlexHouse at the Danish Technological Institute in Taastrup. EnergyFlexHouse is a multiflexible development and demonstration building designed by Henning Larsen Architects, which allows you to test energy-optimised constructions and components. Subsequently, the multi-functional concrete structures have been applied in three demonstration rooms at Kolding Campus – University of Southern Denmark (cf page 45).

culation tool BE10 of the Danish Building Research Institute, the project will additionally develop a calculation methodology with a view to document the energy savings generated by the thermal mass.

 he project has looked into the T opportunities for exploiting the thermal potential of concrete with a view to create a good, steadier indoor air quality. The project results are primarily aimed at suppliers of concrete structures as well as architects and engineers. The project is expected to be completed during 2012. Project team  Henning Larsen Architects Aalborg University The Danish Technological Institute, Concrete Centre Orbicon The Danish Property Agency The project is supported by the Energy Technology Development and Demonstration Program (EUDP) under the Danish Energy Agency.

In future, optimised concrete structures will form an active part of the energy systems of new and existing buildings. As an input to the energy calDESIGN WITH KNOWLEDGE |

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The Adaptable House Copenhagen 22.05.2012

The design of ‘The Adaptable House’ addresses the continuously changing needs and requirements that we have for our home through life. The various parameters are divided into different categories which each has an influence on the building design. 136 | DESIGN WITH KNOWLEDGE | NEW ROLES | THE ADAPTABLE HOUSE

SKE TCH PROPOSAL Collaboration between

innovation

9.0 New roles

The Adaptable House ’The Adaptable House’ is based on the ever-changing circumstances of life. The house is one out of six demonstration buildings that aim to reduce CO2 emissions during the creation process and in the everyday use after completion. Our needs and requirements for our home change all through life. Today, it requires both time and resources to adapt your home to these needs. ‘The Adaptable House’ aims to change this. The project was initiated by Realdania Byg and seeks to identify the possibility of creating a singlefamily house that is adaptable to changes in aesthetics, functional requirements and technological developments.

 he project seeks to identify the T possibility of creating a singlefamily house that is adaptable to changes in aesthetics, functional requirements and technological developments. The project will result in a built house of 142 m2 that can be disassembled into components without destruction, while at the same time meeting the 2015 density requirements of Danish building regulations. The house will be so flexible that it can adapt to new spatial requirements at a high rate of change – while continuously taking into account how the replaced components can be reused and form part of new cycles.

‘The Adaptable House’ is based on five drivers : comfort, privacy, function, demography and lifestyle. The individual driver features a variety of different scenarios, which again feature different degrees of changeability. The house aims to comprise all drivers and scenarios to be able to accommodate all life situations – if you can avoid rebuilding or extending your house when children are born or move out, for instance, you will not harm the environment with building materials and waste. As one out of six experimental house projects, ‘The Adaptable House’ aims to identify different aspects of resource consumption and derived CO2 emissions, just as it looks into the various possibilities for minimising CO2 emissions during design, construction and use. All six projects are designed and built as single-family houses at a normal construction budget. The project is financed by Realdania Byg, and the house will be completed in 2013. Project team GXN Henning Larsen Architects Client Realdania Byg

The house is made up of accessible components, based on an aesthetic and technological module structure. DESIGN WITH KNOWLEDGE |

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10.0 Renovation

by Signe Kongebro

Energy renovation and complete renovation The same issues and means of incorporating energy apply to new buildings and existing buildings. The renovation potential is substantial and can boost a sustainable development everywhere. New buildings account for less than 1 % of the total building stock in Denmark. It takes years from the building sketches have been submitted to the completed building is inaugurated. Thus, our knowledge on green building will always be more extensive and more developed than reflected in the buildings that are currently under construction. In the last decade where sustainability has featured high on the agenda – and the possibilities for achieving funding for research and development projects have been good – this gap has become wider. And as regards old buildings, the gap is even more significant. Many existing buildings do not meet today’s most basic requirements for energy and functionality. This gap between knowledge and reality illustrates the necessity of activating and applying our knowledge in practice. There is a large need and potential for renovation – and this is a field where stateof-the-art knowledge can make a real difference. Without extensive, common efforts to renovate the existing building stock in the years to come, Denmark will have difficulties meeting its ambitious climate goals. The concept of sustainability is complex when you really dig into it. There are many interdependent views on, nuances and means of sustainability. The same applies to renovation whose complexity has also increased. A renovation is more than a solution to a specific problem, for instance a hole in the roof. Perspectives have increased. From being a limited quality enhancement of something exist-

ing, renovation has become a significant element in a wider global vision for sustainability – for which Denmark raised the bar with its political settlement on energy in spring 2012.

It is about creating added value in all areas : improved health and comfort, better architecture, careful energy and environmental considerations and a sound economy. It is not enough to fix the hole in the roof. Renovation projects should add value to all aspects of sustainability. Until now, the large visions for the development of our cities and buildings have only been aimed at new buildings. However, with the changed perspective on the existing building stock, renovation will be one of the most important initiatives in the coming years. A sustainable development of society is not possible without renovation. Traditional renovation projects increase the utility value while the energy consumption remains unchanged. The specific problem, for instance a hole in the roof, forces the building owner to carry out a renovation. In this connection, questions about energy consumption and the statutory energy labelling scheme often arise. Thus, the concept of energy renovation has already become a fixed term in the building industry.

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 raditional renovation projects address specific problems, for T instance a leaky roof. Complete renovations, on the other hand, take a holistic approach, based on the vision of enhanced quality. The illustration shows the school Klostermarksskolen in Roskilde where the ambition was to achieve an improved indoor air quality and thus improve the teaching conditions for pupils and teachers. By establishing a roof over the outside space between two teaching wings, you achieve improved daylight conditions and natural ventilation. Please refer to page 48 and forward for additional project information.

However, it is often carried out without taking into account the use of the building after completion. For instance, the roof is changed, the building is re-insulated or a mechanical ventilation system is installed. For the user, this can result in thicker walls, lower ceilings or everyday noise from the ventilation system. At the same time, the renovation project itself as well as the day-to-day operation of the new ventilation system often entail increased monthly rents. Thus, the gain of the energy renovation is paid for with poorer building quality.

Instead of a conventional energy renovation, you can choose to carry out a complete energy renovation where focus is on the entire value chain : health, comfort, architecture, energy and economy. Instead of a conventional energy renovation, you can choose to carry out a complete energy renovation where focus is on the entire value chain : health, comfort, architecture, energy and economy. The idea is that these five aspects engage in close interaction and mutually strengthen the quality of each other. Complete renovations ensure an optimal increase of the building’s total value. Initially, the potential must be clarified through a thorough screening of the technical installations, building physics and building application.

In a renovation project, several parameters and interests must be taken into consideration. Complete renovations pose an even higher number of challenges. The initiative for renovation projects is often taken by public planners, politicians or professionals who all go after long-term strategies. They often think in time perspectives of several decades and accept that the renovation is expensive to begin with – but that costs will be recouped in a few years in terms of energy savings and increased quality. If the initiative is taken by private house or building owners, on the other hand, the time perspective is shorter. They often choose projects that have an immediate effect and directly compare the renovation expenses with the profit gained through lower energy costs. The investment must make a profit within a few years as privately owned buildings regularly change hands. This issue has previously been addressed by the Danish green think tank Concito who calls it the ‘paradox problem’. Often, energy renovations will not benefit the investor because costs often take years to recoup through lower energy bills. This means that renovation projects are often abandoned because the decision to carry it out is taken on very different grounds. Politicians and planners look at ‘the big picture’ ; while a short way from cause to effect is the main concern of private building owners. Complete renovation is not just a question of lower energy costs. It is about creating added value in all DESIGN WITH KNOWLEDGE |

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areas : improved health and comfort, better architecture, careful energy and environmental considerations and a sound economy. We need to renovate. There is no doubt about it. Therefore, we need to find a common platform to work from. Decisionmakers should have a common understanding of the possibilities of renovation. Intensifying the observation and putting more efforts into analysing the existing conditions will allow us to find the right balance between modernisation, renovation and revitalisation. The means are the same whether we are dealing when a renovation or a new building project : daylight, geometry, materials etc. The difference is that, in a renovation, some parameters are determined in advance. Complete renovations grasp and unfold the full potential of the specific project.

Complete renovations ensure an optimal increase of the building’s total value. User involvement is decisive to ensure satisfaction with the comfort and indoor air quality of the building after completion. Therefore, involvement of users and stakeholders while the building is in operation is an important criterion for the success of the project. This can be done by collecting data on energy consumption and indoor air quality and – based on the collected figures – make an overall assessment of the possibility for further measures

or optimisation of existing conditions. This durable, sustainable and dynamic approach ensures continuous development and improvement of the energy consumption.

Many existing buildings do not meet today’s most basic requirements for energy and functionality. The same technology platform can be used to collect data in the operating phase with a view to achieve regular, clearly laid-out documentation for the obtained effects. The level of detail will correspond to the energy potential of the building in terms of for instance energy consumption for lighting, ventilation, individual building parts etc. The level of detail is established in collaboration with building owners, users and stakeholders to clarify how to further optimise the effort in specific areas. Renovations based on the right perspective require the ability to zoom in and out. The specific problems must be solved and the solutions must be in line with the visions for sustainability. The research presented in this book has looked into a number of complex issues. By communicating the addressed issues in short, intelligible cases sup-

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10.0 Renovation

Energimærke G

Bygninger med stort potentiale

F

IN

G

Traditionel renovering med fokus på brugsværdi

HE

D Bygninger med lille potentiale

C

Energirenovering med fokus på energi

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E

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 raditional renovation projects are carried out to solve a specific T problem whereas complete renovations are raised to a more abstract vision level before a specific solution is decided upon.

A Lav investering pr. m2

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ported by graphic illustrations, the most important aspects in building design and urban planning have been reviewed. This simple approach makes the research results directly applicable in our everyday life and work. Sustainable building is not only a technological discipline. Genuine low-energy is incorporated into the building from the beginning. Energy-efficient measures should be permanently integrated into a functional design that they cannot be detached from. Daylight, geometry, functional layout, materials and comfort are all key parameters in a welldefined energy strategy and are thus permanently integrated into the building. The key to beautiful, comfortable and energyefficient buildings is found in the interaction between architecture and technology. This book provides the reader with the insight necessary to formulate and maintain an overall sustainable vision.

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Research articles

Research articles The following pages present a selection of research articles on sustainable building. The articles are written in a more specialised, scientific language compared to the cases and descriptions of the preceding pages. In connection with the preparation of their master’s thesis at the Technical University of Denmark in 2007, Jakob Strømann-Andersen and Michael Jørgensen worked on an actual project that was in the process of design at Henning Larsen Architects – a low-energy office building in Amsterdam. The thesis showed a great potential for energy-optimising the design by simulating the energy consumption at an early design stage. This resulted in two PhD research projects, later supplemented with the research of PhD Martin Vraa Nielsen. The three projects complement and enrich each other and together provide an overall picture of the energy-related issues that determine the potential for sustainable building. Jakob Strømann-Andersen's PhD thesis shows that urban development plans and master plans have far larger influence on the energy consumption of cities and buildings than realised until now. The design of master plans has a very direct influence on the buildings within the plan and a significant impact on the energy consumption of the individual buildings. The building volumes and their orientation influence each other : daylight, microclimate, wind and noise conditions are partly defined by the adjacent buildings. The project also demonstrates that there is a great potential in focusing more on daylight in the planning of cities and considering daylight as an important common resource. Michael Jørgensen has examined the connection between the different building parameters that influence energy consumption. His research has looked 142 | DESIGN WITH KNOWLEDGE | RESEARCH ARTICLES

into the design of new buildings and the dynamic potential found in the interaction between geometry, building physics, components and system solutions. The research illustrates that the right dimensioning of spatialities, volumes and an optimal organisation of building functions can minimise the need for technical installations – ventilation, cooling and heating – and that they constitute a complex landscape of variables that must be counterbalanced in order to energy-optimise a building. Martin Vraa Nielsen's research examines the design of facades, their dynamic potential and influence on the energy consumption – an area where architects and engineers have to define a ‘modus operandi’ with room for the competencies of both professions. The facade form an important element of the architectural expression of a building and at the same time serves to regulate the daylight and the influence of the sun on the indoor air quality. The facade openings, the design and size of windows interact with the technical installations : solar protection, climate control, insulation and the connection to other system solutions in the building. The research projects have resulted in a wide range of published articles. The following pages provide a summary of each PhD project and present one research article from each project. This provides a deeper insight into the projects and the complexity of the field of research.

List of publications Jakob Strømann-Andersen, Michael Jørgensen and Martin Vraa Nielsen have presented their research on sustainable building at several conferences and in a number of international, scientific journals. The urban canyon and building energy use : Urban density versus daylight and passive solar gains J. Strømann-Andersen, P.A. Sattrup Published in : Energy and Buildings, 43, Issue 8, August (2011) 2011-2020 Building Typologies in Northern European Cities – Daylight, Solar Access and Building Energy Use J. Strømann-Andersen, P.A. Sattrup Accepted for publication : Journal of Architectural and Planning Research, November 2011 Urban Daylighting : the impact of urban geometry, facade reflectance and window to wall ratios on daylight availability inside buildings A. Iversen, J. Strømann-Andersen, P.A. Sattrup Submitted for publication to  : Building and Environment, December 2011 Urban design and pedestrian wind comfort – a case study of King Abdullah Financial District in Riyadh J. Strømann-Andersen, J.C. Bennetsen Accepted for publication  : Environment and Planning B : Planning and Design, 2011 Integrated Design – paradigm for the design of lowenergy office buildings M. Jørgensen, M.V. Nielsen, J. Strømann-Andersen Submitted for publication to : ASHRAE Winter Conference, 2011, Las Vegas, Nevada

A methodological study of environmental simulation in architecture and engineering – Integrating daylight and thermal performance across the urban and building scales P. A. Sattrup, J. Strømann-Andersen Submitted for publication to  : Symposium on Simulation for Architecture and Urban Design, 2011, Boston, MA, USA Sustainable Cities – Density versus solar Access ; A Study of Digital Design tools in Architectural Design P. A. Sattrup, J. Strømann-Andersen Submitted for publication to  : ISES Solar World Congress, 2009, Johannesburg, South Africa Energy Design : Message to Staff on Spaceship Earth J. Strømann-Andersen Published in : ArkitekturM, Volume 1, No. 5, 2009, Arkitektens Forlag Climatic Diversity in the City J. Strømann-Andersen Published in : Byplan, Volume 62, No. 3, September 2010 Thermal Observatory – Installation proposal P.A. Sattrup, J. Strømann-Andersen Proposal for : Charlottenborg, Spring Exhibition 2010 and 24/7

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Investigation of Architectural Strategies in Relation to Daylight and Integrated Design M. Jørgensen, A. Iversen, L. Bjerregaard Jensen Published in : Journal of Green Building, Volume : 7, Issue : 1, pages 40-54, 2012 Quantifying the potential of automated dynamic solar shading in office buildings through integrated simulations of energy and daylight M. V. Nielsen, S. Svendsen, L. Bjerregaard Jensen Published in : Solar Energy, Volume 85, Issue  5, pages 757-768, 2011 Energy renovation of listed buildings L. Bjerregaard Jensen, M. V. Nielsen Part of : Proceedings of ISES Solar World Congress 2011

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Summary

Integrated Energy Design in Master Planning Summary of PhD thesis by Jakob Strømann-Andersen The PhD thesis examines city structures and buildings in an energy-related context and applies the generated knowledge to design energy and comfort-optimised cities and buildings. The parameters are : the structure of nature, the city and landscape ; geometry and interrelations ; possibilities and limitations between light, shadow, sun and wind. The thesis has a threefold objective : (1) to communicate the relationship between city density, typologies, materiality and energy consumption of buildings ; (2) to analyse how scientific knowledge can be integrated into the early planning and design stages (Integrated Design) ; (3) to illustrate the architect’s responsibility and opportunity in terms of rethinking the role of architecture, based on new objectives and new knowledge.

tion process is taken when the architect makes the first line. This is when the structure of and prerequisites for the performance of the city and building are determined. Thus, optimising the spatial properties (city density, typologies and materiality) should have a higher priority in terms of energy compared with optimising the technical installations. This ultimately means that that the architect has a larger responsibility than the engineer in the design process.

The research results show that the impact of the city structure on the energy consumption of buildings is much more significant than realised until now. The project incorporates daylight as a key parameter, which provides a more accurate and dynamic description of the issue. In addition, the results indicate that there is a limit to density (200300 %) if the goal is an energy-optimised city. The potential for use of solar energy and daylight must be considered – or even protected – as a common resource in urban planning. The most important qualitative observation of the project is that the first step in an energy-optimisaDESIGN WITH KNOWLEDGE |

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Contents lists available at ScienceDirect

Energy and Buildings journal homepage: www.elsevier.com/locate/enbuild

The urban canyon and building energy use: Urban density versus daylight and passive solar gains J. Strømann-Andersen a,∗ , P.A. Sattrup b a b

Department of Civil Engineering, Technical University of Denmark, Brovej Building 118, 2800 Kgs. Lyngby, Denmark Institute of Building Technology, Royal Danish Academy of Fine Arts School of Architecture, Philip de Langes Allé 10, 1435 Copenhagen K, Denmark

a r t i c l e

i n f o

Article history: Received 8 September 2010 Received in revised form 30 March 2011 Accepted 10 April 2011 Keywords: Urban density Energy use Daylight Solar radiation Integrated design

a b s t r a c t The link between urban density and building energy use is a complex balance between climatic factors and the spatial, material and use patterns of urban spaces and the buildings that constitute them. This study uses the concept of the urban canyon to investigate the ways that the energy performance of low-energy buildings in a north-European setting is affected by their context. This study uses a comprehensive suite of climate-based dynamic thermal and daylight simulations to describe how these primary factors in the passive energy properties of buildings are affected by increases in urban density. It was found that the geometry of urban canyons has an impact on total energy consumption in the range of up to +30% for offices and +19% for housing, which shows that the geometry of urban canyons is a key factor in energy use in buildings. It was demonstrated how the reflectivity of urban canyons plays an important, previously underestimated role, which needs to be taken into account when designing lowenergy buildings in dense cities. Energy optimization of urban and building design requires a detailed understanding of the complex interplay between the temporal and spatial phenomena taking place, merging qualitative and quantitative considerations. © 2011 Elsevier B.V. All rights reserved.

1. Introduction One of the most basic and fundamental questions in urban master planning and building regulations is how to secure common access to sun, light and fresh air, but for the owners of individual properties, it is often a question of getting the most of what is available. There is potential for repetitively recurring conflict between public and private interest. Solar access and the right to light remain contested territory in any society, vital as they are to health, comfort and pleasure. Traditional urban planning has sought to control the proportions of the streets, because the basic geometry of building heights and distances between buildings regulates access to light and solar heat. Zoning laws and building regulations usually establish heightto-distance ratios that limit the overshadowing that buildings may cause for public spaces and other buildings. A similar geometric abstraction of urban space – the urban canyon [1] – has been used in urban climatology, to describe the way that urban spaces create special environmental conditions. It is a spatial archetype that allows us to integrate knowledge from several different specialized

∗ Corresponding author. Tel.: +45 4525 1868; fax: +45 4525 1700; mobile: +45 6170 7016. E-mail address: jasta@byg.dtu.dk (J. Strømann-Andersen). 0378-7788/$ – see front matter © 2011 Elsevier B.V. All rights reserved. doi:10.1016/j.enbuild.2011.04.007

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fields of research. In geometric terms, the urban canyon is described as the height/width ratio of the space between adjacent buildings. Cities develop over time, and the proportions of urban canyons have long lasting impacts on the future energy consumption for the heating, cooling and lighting of the buildings that define them and the environmental qualities of the streets, squares, courtyards or gardens that comprise them. Urban development is a rather slow process in most industrialized societies, but the impact of site conditions on building energy use multiply over the years – more than other processes that affect a buildings performance over its lifetime. So, considering that one of the main challenges to architects and engineers in the next decades will be how to improve the energy performance of our buildings and cities, we need to improve our knowledge of both urban and building design through research on the dynamic interplay between climate, context and building energy use. The passive properties of buildings are likely to play a much more important role in the total energy consumption, as winter heat losses are reduced with better insulation, glazing and air tightness. Urban densification is one strategy for sustainable development, focusing on energy savings through efficient transport systems, shared infrastructures and minimizing heat gains and losses that dominate energy budgets. It has been established that densification is a balancing act between these opportunities on the one hand, and ensuring solar access for low-energy buildings and urban

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comfort on the other. Yet, the intricate connections between urban climate, urban form and energy use of buildings remain a subject that requires further research [2]. In the already built cities of northern Europe, urban density is of particular concern, because the high latitudes and the associated low solar inclinations mean that the urban geometry affects solar access much more here than in other urban centres around the world. Overshadowing is an obvious problem. The relative scarcity of light, particularly during the long winter season, is increased by the overcast skies that dominate the region throughout the year, creating special conditions for the region’s architecture and planning to deal with. Recent developments in computation, such as Geographic Information Systems (GIS), Building Information Models (BIM), and detailed climate-based thermal, shading and lighting simulation software, offer new insights into the dynamic relationship and specificities of climatic conditions and the individual building’s use and properties, helping us identify the balancing points of solar gains and daylight conditions resulting from urban geometry. These insights can serve as an improved basis for energy-optimized urban planning and building design. The building design process often has the urban scale as one of its very first concerns, so knowledge of the relative impacts of urban geometry is an important asset for energy-optimized architecture, because energy savings from design choices on the urban scale are very long-term, and lessen the need for advanced technical measures, such as shading systems, ventilation systems and active systems like PVs on the building scale, that have high investment costs and short useful lifetimes. A serious deficiency in the energy calculations that are now mandatory in many countries is that they focus on the performance of the individual building, and neglect the interplay between the building and context due to overshadowing. As will be demonstrated in this paper, buildings in dense urban settings can not only make positive contributions to the energy and comfort performance of neighbouring buildings through their reflectance of daylight, but may gain qualities themselves in doing so. The analysis focuses on north-European cities, with the climate of Copenhagen (55.40◦ N 12.35◦ E) used as reference, but both the methodology applied and the findings are relevant for urban development and building design globally. In Denmark, low-energy buildings will be the new standard by 2015. Primary energy use levels of ≈35 kWh/m2 /year for housing and ≈50 kWh/m2 /year for office buildings will be the minimum for compliance for new buildings, with further increases in energy efficiency being aimed at in the near future. Incentives and regulations to improve the performance of the existing building mass are being discussed for implementation [3]. The key questions of this study are: 1 How do the height/width ratios of urban canyons affect building energy use for lighting, heating and cooling? 2 How big is the relative impact of the height/width ratio on the total energy use compared to unobstructed solar access? The first question aims at understanding the physical and temporal phenomena of energy exchanges, and their interdependencies. This requires an in-depth investigation of the urban canyon to study the differences in energy potential available to apartments or office subdivisions on the various levels of a building. The second question allows for a quantitative comparison of the impact of the energy distribution of solar radiation and daylight in the urban canyon building requirements for heating, cooling and artificial lighting. The relative impact on these requirements is necessary and useful information when discussing, or indeed designing for, the energy optimization of buildings and urban spaces in the effort to improve cities and buildings.

2. Background The urban canyon has been used in urban climatology as a principal concept for describing the basic pattern of urban space defined by two adjacent buildings and the ground plane. Apart from its metaphorical beauty, the key quality of the term is the simplicity it offers in describing a repeated pattern in the otherwise complex field of urban spaces and building forms. While the impact of urban geometry on the urban microclimate is well established, studies have tended to focus on problems of overheating in warm climates, the urban heat island effect, and urban comfort. The distribution of air movement and temperature in urban canyons and its potential for energy savings related to ventilation has been the subject of a number of studies [4,5], connecting urban canyons to the field of building energy use, but their impact on the full range of energy uses in buildings has not been thoroughly investigated. At the other end of the building-urban space divide, energy models and simulation techniques have been developed to study and describe the energy performance of buildings in relation to the surrounding climate. However, these models are generally intended for use by building designers and tend to consider buildings as self-defined entities, either neglecting or grossly simplifying the importance of phenomena that occur on the urban scale. Nevertheless, there have been some investigations, e.g. Littlefair [6], of the link between the urban geometry and the individual building’s energy performance. Ratti et al. [7] document an effect of almost 10% in the relationship between urban morphology and the annual per-metre energy consumption of non-domestic buildings. They demonstrate the effect using a calculation that compares the DEM (Digital Elevation Model) with the LT method (Lighting and Thermal) developed by Baker and Steemers [8]. The most detailed and complete investigations of urban obstruction affecting energy use are presented by Baker and Steemers [9]. Using the LT method, they derived a correction factor to modify the specific energy consumption for non-domestic buildings. The LT method is a tool for strategic energy design and it should not be regarded as a precision energy model. Li et al. [10], in their study of vertical daylight factor (VDF) calculations, demonstrate that daylight is significantly reduced in a heavily obstructed environment. A study of VDF predicted by RADIANCE simulation demonstrates that an upper obstruction (˛U ) at 60◦ and a lower obstruction (˛L ) at 10◦ reduce the daylight level by up to 85%. The results also indicate that the reflection of the obstructive buildings can be significant in heavily obstructed environments, such as rooms on lower floor levels facing high-rise buildings. Few, if any studies have investigated the results of a combined and fully integrated dynamic energy simulation. An earlier study by Sattrup and Strømann-Andersen showed how the precision of energy simulation for various types of building in context improves dramatically, when developed in a multilayered, climate-based, dynamic simulation [11]. New tools like IES-Virtual Environment 6.0.2/RADIANCE offer multilayered analysis of thermal and lighting performance integrated with Building Information Models (BIM), and they can handle the modelling and dynamic simulation of complex urban geometry.

3. Method The research was done using a quantitative study of the simulated energy performance of digital models of buildings lining a series of variously proportioned urban canyons as the basis for a qualitative discussion. The research was conducted through the design of models based on types of urban space, building and user pattern. The type is a key concept to describe generic patterns associated with buildings. While generic models obviously lack a lot of the variation and diversity that could make them architecturally

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∞ ∞

30 m 0.5 200

20 m 0.75 250

15 m 1.0 285

10 m 1.5 335

7.5 m 2.0 365

5m 3.0 400

Fig. 1. Contemporary urban (re)developments. (A) Offices. Kampmannsgade, Copenhagen. H/W ratio 0.8. (B) Housing. Viborggade, Copenhagen, H/W ratio 1.25.

appealing, they have the abstract quality of identifying key parameters which can be varied and studied for their relative impact on overall performance. Building types or typologies have been discussed throughout the history of architecture, and have influenced recent architectural thinking. As Eisenman notes in his introduction to Rossi [12], type refers to both object and process, and thus offers a basis for invention because it describes an essence of design to be investigated through research. Types are used in several studies of buildings, environment and energy. As Hawkes [13] says: “Type offers the possibility of translating the results of technically-based research into a form that renders them accessible to designers”. In this study, types are used on three levels: • The urban canyon is a type, which is itself an abstraction of other types: the street, the square, the courtyard, the garden, etc. • The building is a type. In this instance the building is of the infill type, forming part of a larger array of buildings facing an urban canyon, as is usual in urban blocks, or building slabs. To achieve detail the building is subdivided in spatial units, such as apartments or office subdivisions, each unit facing in only one direction. This allows differentiated results for 4 orientations. The building type has two variations: housing and office linked to the types of user patterns for homes and workplaces. • The use pattern is a type. The two user patterns studied are for homes and workplaces, the main difference being their complementary daily and weekly occupation patterns.

historical development of the city, and the societal and technological forces that guided it. Nevertheless, the patterns persist and are repeated in contemporary urban (re)developments (Fig. 2). Each canyon was defined for a 5-storey building with a height of 15 m, allowing easy comparison and individuation of the resulting energy performance. Lower H/W ratios exist, of course, in the suburbs, but were not the subject of study here. The relative ‘fit’ of the urban canyon concept to real urban patterns is scale-dependent. Because the urban canyon concept is an abstraction of the spatial complexities of real cities, its relation to density is somewhat simplified too. The extra solar access at street intersections and the lateral shading occurring at building angles are ignored. But if an ideal urban pattern consisting solely of uniformly distributed building slabs or terraced houses is presupposed, in which every second canyon is for access and traffic and the other a semiprivate communal space, like a courtyard or garden forming part of the building’s plot, density can be described using a rough plot ratio indicator (Table 1).

Since the aim in this study is to highlight the effects of urban density upon building energy consumption, default values are assigned to all variables except those that relate to urban geometry. Simulation was done on two levels: that of the radiative environment of the urban canyon itself, including the dispersion of daylight, and that of the energy performance of the buildings in the urban canyon. 3.1. Urban canyon types, height/width ratios The urban patterns of Copenhagen was taken as reference, and defined six different canyons by their height/width ratio (H/W) ranging from 3.0 to 0.5 (Table 1). The highest H/W ratio spaces are found mostly in the medieval parts of the city, such as passages and very narrow courtyards, and the lowest ratio reflects conditions found in urban squares, boulevards and more spatially generous courtyards (Fig. 1). The densities are closely associated with the

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Fig. 2. Typical urban patterns and proportions of urban canyons in Copenhagen.

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J. Strømann-Andersen, P.A. Sattrup / Energy and Buildings 43 (2011) 2011–2020 Table 2 List of energy factors as stated in the Danish building regulation [25] and how they are used in the simulation.

Fig. 3. Validated units. (A) Office unit (window-to-wall ratio 40%). (B) Housing unit (window-to-wall ratio 20%).

3.2. Urban-canyon simulation, radiative and daylight environment The radiative environment was studied using Autodesk Ecotect Analysis 2010. Ecotect is a highly visual architectural design and analysis tool that links a comprehensive 3D modeller with a wide range of performance analysis functions [14]. For solar radiation calculations, ECOTECT uses hourly recorded direct and diffuse radiation data from the weather file (*epw). In addition to standard graph and table-based reports, analysis results can be mapped over building surfaces or displayed directly in the spaces. This includes visualization of volumetric and spatial analysis results. In this study, the RADIANCE-based simulation environment DAYSIM was used for all dynamic simulations of outdoor and indoor illuminance due to daylight. DAYSIM applies the Perez sky luminance model [15] to simulate indoor illuminance in arbitrary sky conditions. It merges the backward ray tracer RADIANCE (Ward and Shakespeare, 1998. G. Ward and R. Shakespeare Rendering with RADIANCE. The Art and Science of Lighting Visualization, Morgan Kaufmann Publishers (1998)) with a daylight coefficient approach and permits reliable and fast dynamic illuminance simulations [16]. DAYSIM allows the simulation of an annual illuminance data set for any specified point and orientation in a given environment. It uses data interpolation from the (*epw) weather file. More detail on the underlying simulation algorithm of DAYSIM can be found in [17,18]. Daylight factors have been used in many previous studies as a simple method of predicting ‘worst case’ scenarios using CIE-standardized skies, but these ignore dynamic weather conditions since they do not incorporate actual climate data, which vary a lot depending on the real-world location. Advances in computing power now allow a detailed hourly analysis and relatively fast calculation of daylight levels using metrics, such as the Daylight Autonomy metric, in which available daylight is quantified combining both direct and diffuse radiation [19,20]. Street canyon surface reflectance variables are: Ground (Albedo) = 0.20 and external wall = 0.45/window = 0.15. Surface reflectance thus depends on the glazing ratios of the adjacent buildings, 20% glazing for housing and 40% for offices. 3.3. Building and user pattern types for offices and housing On either side of the canyons in our model, buildings are defined by 5 storeys of 50 m2 spatial units, each with a 3 m floor to floor height, 5 m room depth and glazing ratios of 20% for housing and 40% for offices (Fig. 3). The proportions of the units are associated with apartments or office rental units commonly found in central Copenhagen. Taken together, 2 spatial units facing opposite directions would constitute a generic 100 m2 apartment or office subdivision, a size that is commonly found, and close to the national average of 110 m2 per dwelling [21]. The room depth falls well into the category of ‘potentially passive’ space [22] in which daylight and solar gains can play a significant role. The model, while generic, is thus linked to the most important geometric factors that regulate the development of the urban fabric over time.

Energy source

Factor

Simulation

Gas and oil District heating Electricity

1.0 0.8 2.5

Heating and DHW Heating and DHW Cooling, Mech. Vent. and Art. Light.

The user patterns are reflected in the different occupation hours and activity levels of the system settings, basically following the working week and the daily rhythm. The user patterns are designated so as to achieve the European standards of indoor environment [23] and reflect differences in requirements for housing and offices. These are not discussed as such (see Appendix A). 3.4. Building types energy simulation The energy calculations were performed using the simulation tool IES-Virtual Environment 6.0.2, ApacheSim/RADIANCE, which creates a fully integrated thermal and daylight simulation with detailed hourly output of the electrical energy consumption for lighting, mechanical ventilation, heating load, cooling load, and indoor operative temperature. The IES-Virtual Environment is an integrated suite of applications linked by a common user interface and a single integrated data model. It qualifies as a dynamic model in the Chartered Institution of Building Services Engineers’ [24] system of model classification. IES-Virtual Environment 6.0.2/ApacheCalc (thermal simulation) does not take the effect of the local microclimate into account. To accurately determine the local wind speed and thereby convective heat transfer on both internal and external boundary surfaces is extremely difficult and could only be done by means of careful measurements or advanced computer simulation. For these reasons, the variation of the surface heat transfer coefficient has been ignored. The glazing ratios used are related to sizes typically found in traditional housing and modern office buildings. The model buildings are very well insulated heavy constructions. Wall U-values are 0.2 W/m2 K. Glazing U-values are 1.5 W/m2 K, g-values are 0.62. See Appendix A for details of default settings and generic user patterns for housing and offices. The lighting system in the rooms is controlled by the illuminance at a reference point. Reference points are placed 0.85 m above the floor and 1 m from the back wall. In offices, lighting is dimmed between full power when no daylight is available and minimum power when the illuminance from daylight in the reference point is above 200 lx. A linear control is assumed. For housing, a manual on/off control is assumed, which means that the lighting is always at maximum power, when daylight in the reference point is under 200 lx. Since not every room in the house is always active, a switched-on-profile of 20% is added. As in the urban canyon simulation, the design simulation weather data is used for the full year simulation. The system settings for the model reflect a building that allows for a certain degree of user adaptation and control over the environment, so as to highlight the impact of geometries and material properties of both building and urban space, not the building technology as such. Energy use is measured in primary energy using primary energy factors corresponding to the Danish building regulations [25] (Table 2). In principle, primary energy use is the total weighted energy. It can be calculated from the unit’s estimated net consumption. The total net energy consumption is divided into five primary needs: (1) Domestic Hot Water (DHW), (2) artificial lighting, (3) mechanical ventilation, (4) cooling load, and (5) heating load.

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Energy use for electric appliances other than these is not considered in this study. Of the five needs, three vary as a function of the urban density. DHW and mechanical ventilation are simulated as constant. In the simulation, it is assumed that the refrigeration system has a COP value (COP = Coefficient of Performance) of 2.5, which means that electricity consumption for cooling counted by a factor 1 to 1 (refrigeration kWh equals electricity kWh). Since the analysis operates in an urban context, it is assumed that the building is equipped with district heating. The heating supply is therefore regarded as having an efficiency of 1 to 0.8. 4. Results and discussion The analysis of the environments of the canyons is presented and discussed first in terms of radiation and daylight, comparing daylight factor and daylight autonomy metrics, and then in comparison with the energy consumption of electricity for artificial lighting in offices, because this is where the greatest impact and the widest diversity of results are found. The total energy consumption of offices is then presented and discussed, followed by an analysis of the energy consumption of housing. 4.1. Urban canyon radiative environment and daylight In Copenhagen, the solar inclination is rather low, particularly in winter, 11◦ at midday winter solstice, 58◦ in summer (compared to 15◦ /62◦ in London), which means that direct solar radiation only grazes the top storeys and roofs of dense urban districts in winter. Overshadowing is an obvious problem. Fig. 4 shows how the average daily distribution of radiation in urban canyons defined by north/south-facing buildings is calculated combining direct and diffuse radiation climate data on an annual basis. It is assumed that diffuse radiation is evenly distributed across the sky dome. The distribution of the radiation level curves is influenced by the sun angle, the climate-based mix of direct and diffuse radiation, and the reflectivity of the building surfaces. When the radiation levels are converted to daylight levels and subjected to a daylight autonomy analysis, it can be seen how the asymmetry of the daylight distribution in the canyons varies greatly between high illuminance levels (>10,000 lx) (Fig. 5) and low illuminance (<500 lx) (Fig. 6). While the low level distribution is relatively even and resembles that of overcast skies, it is nevertheless slightly asymmetrical because it does include direct light that comes in at low angles at times of the day when the light is not intense. The high illuminance levels are pronouncedly asymmetrical, yet not more so than to include a significant proportion of diffuse and reflected light. An interesting point is to note how the intersection of the 10–15% daylight autonomy curve at the north-facing fac¸ade seems to follow the inclination of reflected light from the top of the opposing fac¸ade coming in at low angles. The reflectance of the urban canyon affects the daylight distribution inside the spatial units significantly. Fig. 7 shows how the daylight distribution of an urban canyon with high wall reflectance (0.75), compared to one with low wall reflectance (0.45), is significantly better and more evenly distributed at the bottom of the canyon and deep inside the spatial units themselves. In the low reflectance canyon, the 80% daylight autonomy curve is almost identical to the sky-dome cut-off angles that are defined by the opposing building, making the daylight almost exclusively dependent on the view of the sky. In the high reflectance canyon, reflected light shows a remarkable capacity to penetrate laterally through multiple reflections and achieve reasonable daylight autonomy lev-

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els of 50% even deep inside the spatial units at the bottom of narrow (10 m, H/W ratio 1.5) canyons. If we consider the light quality experienced by a person working away from the window on the ground floor, in the first case, the person might be almost totally dependent on artificial light, while in the second, the person might have much more of the variation and quality associated with daylight, even though filtered by the urban context. It becomes clear that overshadowing is not the only way buildings affect the energy use of their neighbours. The reflectivity of their surfaces also significantly affects the availability and distribution of daylight, and the associated energy use for artificial lighting of their surroundings. This simple fact, which nevertheless holds enormous design potential for architects and engineers, should lead to design guideline developments in urban planning and zoning regulations, because the urban geometry can be considered a daylight and energy distributing armature proper. The light and energy of the sun, exploited and redistributed through a careful mediation of its temporal, spatial and atmospheric characteristics. 4.2. Energy consumption for offices Fig. 8 shows a general increase in energy consumption as a result of increased density as expressed by the H/W ratio. Because the results are balanced by a 2.5 primary energy conversion factor for electricity use compared to heating and cooling, artificial lighting becomes both the dominant factor in energy use at very high densities and the factor most susceptible to changes in density. Cooling demand decreases with density due to overshadowing, while the reduction in solar gains due to the very low solar altitude during the heating season results in increased use of energy for heating (Fig. 10). Artificial lighting has the largest variability of the individual energy needs. Energy use for artificial lighting is doubled even at the lowest density (H/W 1.0) compared to an unobstructed context, and increases more than six times at the highest density (H/W 3.0) (south 2.8–17.2 kWh/m2 /year). Thus, comparing north/south-facing buildings to east/westfacing ones, it is interesting to note that an unobstructed context favours north/south-oriented office buildings while the opposite is true in dense urban canyons, with H/W ratios above 1.0. For east/west-facing buildings in unobstructed environments, the heat gains from the early morning and late afternoon sun would lead to overheating in summer, but this is partially blocked by the urban context and mostly affects just the upper levels. Instead, reflected light contributes positively to daylight in the lower levels of the buildings on the other side of the canyon. As the sun nears its maximum, its lateral angle towards the fac¸ade means that the area of east/west-facing windows towards the sun diminishes and receives less heat. At this point of the day, the direct radiation penetrates the length of the urban canyon at all times of the year, unless laterally obstructed, and contributes to raising the daylight levels at the bottom of the urban canyon through reflection. Another interesting observation is that a north-facing building needs less energy for artificial lighting than a south-facing one at the highest density in this study (Fig. 11). It was found to be mainly due to the fact that the proportions of the urban canyon allows direct light to be reflected off the opposing fac¸ade and into the lower north-facing offices. Fig. 9 shows the relative variation in the total energy consumption from free horizon to a height/width ratio of 3 varies from between +2.1% and +30.2% for offices depending on the geographic orientation. The greatest relative variation was found with the south/north building orientation. The south-oriented units in particular stand out by having a large relative influence even with large canyon widths. For example, the relative influence is +10% for a street width of 20 m (H/W 0.5). This means that the relative variation at is 2–3 times greater than with other orientations. The largest

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Fig. 4. Average daily solar radiation in street canyon. Calculated in ECOTECT (working hours 08–17, contour range 500–2500 Wh in steps of 200 Wh). Weather data, Copenhagen (*epw).

Fig. 5. Annual illuminance > 10,000 lx in street canyon. Calculated in RADIANCE/DAYSIM (working hours 08–17, contour range 0–50% in steps of 5%). Weather data, Copenhagen (*epw).

Fig. 6. Annual illuminance > 500 lx in street canyon. Performed in RADIANCE/DAYSIM (working hours 08–17, contour range 85–95% in steps of 1%). Weather data, Copenhagen (*epw)

Fig. 7. Annual illuminance > 200 lx in street canyon with surface reflectance variables, Ground (Albedo) = 0.20. Calculated in RADIANCE/DAYSIM, (working hours 08–17, contour range 0–100% in steps of 10%). Weather data, Copenhagen (*epw). (A) Reflectance external wall = 0.45. (B) Reflectance external wall = 0.75.

relative variation is the need for cooling. Here the energy consumption is reduced almost exponentially with the increase in H/W ratio. For example, the need for cooling is reduced by an average of −150% with a H/W ratio of 1.5 (canyon width 10 m) compared to free hori-

zon. With very narrow canyons, H/W higher than 1.5, the need for cooling is reduced to insignificant amounts. Energy consumption not only varies as a function of the street width, but also for the individual building units. Each unit has a

Fig. 8. Total primary energy consumption (kWh/m2 /year) for a 5-storey office building as a function of urban density.

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Fig. 9. (%) Relative deviation (%) of energy consumption a 5-storey office building as adensity function of urbanto density compared to free horizon. Fig. 9. Relative deviation of energy consumption for a 5-storey officefor building as a function of urban compared free horizon. Fig. 9. Relative deviation (%) of energy consumption for a 5-storey office building as a function of urban density compared to free horizon. Journal Identification = ENB

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Fig. 9. Relative deviation (%) of energy consumption for a 5-storey office building as a function of urban density compared to free horizon. J. Strømann-Andersen, P.A. Sattrup / Energy and Buildings 43 (2011) 2011–2020 Journal Identification = ENB

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Fig. 9. Relative deviation (%) of energy consumption for a 5-storey office building as a function of urban density compared to free horizon.

Fig. 9. Relative deviation (%) of energy consumption for a 5-storey office building as a function of urban density compared to free horizon.

2 Fig. 10. 2Solar (kWh/m /year) a 5-storey office building (north/south) as adensity. function of urban density. Fig. 10. Solar gain (kWh/m /year)gain for a 5-storey officefor building (north/south) as a function of urban Fig. 10. Solar gain (kWh/m2 /year) for a 5-storey office building (north/south) as a function of urban density.

as anwhole example, the whole suffers summer overheating, energy consumption depending on the floor onas which the an example, the building suffersbuilding summer overheating, fic energy specific consumption depending on the floor on which the Fig. 9. Relative deviation (%) of energy consumption a 5-storey building as a function urban density compared to free horizon. overheating, an example, theof whole building suffers summer specific energy consumption depending on the floor on for which the officeas Fig. 10.energy Solar gain (kWh/m2the /year) increases forwhich a 5-storey office building (north/south) asunits aby function urbancooling, density. which our model dealof with by increasing cooling, but only is located. Generally the consumption the our model units deal with increasing but only is located. unit Generally the energy consumption increases which our model units deal with by increasing cooling, but only unit is located. 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Generally the energy the sunshine winter day. As winters are verywith often overcast with the same the relative energyofperformance of the sunshine on a winter day.on Asa winters are very often overcast ame distribution of distribution the relative of energy performance the 2 sunshine on aunits winter day. As winters aredirect very radiation often overcast with the same the distribution of Fig. the relative energy of the the top level from heat of and enjoy narrower canyon and the closer the unit performance gets tofor the ground. 10. Solar gain (kWh/m /year) a 5-storey office building (north/south) as gain a function ofthe urban density. light levels well below 2000 lx, the sky dome does not contribute units. Within the overall pattern of higher energy use at the botlight levels wellmost below lx, the skysavings dome doesartificial not contribute . Within the overall the pattern of higher energyand usecanyon at the widths botof 2000 thewell occasional light that with However, various orientations light levels below 2000 lx, for the sky dome does notcomes contribute units. Within the overall pattern of higher energy usedo atnot theshow botas an example, the whole building summer overheating, specific energy consumption on the floorbuildings onmuch, whichtend the much, quantitatively, to establishing indoor lighting levels above tom same of canyons, the narrowest canyons, north/south-facing quantitatively, to establishing indoor lightingsuffers levels above of the narrowest north/south-facing buildings tend sunshine on a winter day. 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East/west-facing buildings showperform abuildings more evenly 4.3. lx, Energy forAshousing 4.3. Energy for housing sunshine onconsumption ais winter day. winters often overcast with the same distribution of thewhich relative energy of the consumption as an example, the whole suffers summer overheating, specific energy consumption depending on theshow floor aon which the mance significantly. East/west-facing buildings more evenly 4.3. Energy consumption forbuilding housing light levels well below 2000 lx, theby sky dome does not contribute units. the overall pattern of energy use at the botlower levels, to such degree as tohigher increase the overall perfordistributed increase inaenergy use along with increases the H/W buted increase in energy use along with increases in the H/W which our model deal increasing cooling, but only unit isWithin located. Generally the energy consumption the Fig. 10. Solar gain (kWh/m /year) increases forin a 5-storey office building (north/south) asunits a function of with urban density. distributed increase inand energy use along with increases in the H/W much, quantitatively, tofrom establishing indoor lighting levels tom of significantly. thethe narrowest canyons, north/south-facing buildings tend the top levelconsumption units gain the heat of direct radiation and above enjoy narrower canyon the closer the unit gets the ground. mance East/west-facing buildings showto a more evenly Energy for housing ratio and the position of the units closer to the bottom of the canyon. and the position of the units closer to the bottom of the canyon. 12 and 13 show that the relative impact of increased denFigs. 12 and 4.3. 13 Figs. show that the relative impact ofartificial increased denas example, the whole building suffers summer overheating, specific consumption depending on floor on which the most theand occasional savings for light that comes with However, the various orientations and canyon widths do not show 200an lx,of which is 13 the threshold value of this model. to favour the upper levels, which perform a lot better than the ratio andenergy the position of thethe units closer towith thethe bottom of the canyon. Figs. 12 show that the relative impact of increased dendistributed increase in energy use along increases in the H/W which our model units deal with by are increasing cooling, but with only unit is located. Generally energy consumption increases the sunshine on a winter day. As winters very often overcast the same distribution of the relative energy performance of the The explanation is in the seasonal changes that happen through he explanation is in the seasonal changes that happen through sity on energy consumption is more moderate for housing than for sity on energy consumption is more moderate for housing than for lower levels, such a the degree as tochanges increase thehappen overall perforthe top level units gain fromis the heat of direct for radiation and enjoy narrower the to canyon and the closer the unitthat gets to the through ground. The explanation isof in seasonal sity on energy consumption more moderate housing than for light levels well below 2000 lx, the sky dome does not contribute units. Within the overall pattern of higher energy use at the botratio and the position the units closer to the bottom of the canyon. Figs. 12 and 13 showsavings that thefor impact of increased denmost ofThe the occasional artificial light that comes with However, orientations and canyon widths not show mance significantly. buildings show a do more evenly 4.3. Energy consumption for housing the year. Ifthe wevarious take East/west-facing the south-facing units the H/W 1.5 canyon ear. If we take the south-facing units in the H/W 1.5 in canyon offices. largest single need inrelative housing ismeans heating. This means offices. The largest single need in housing is heating. This much, quantitatively, to establishing indoor lighting levels above tomyear. of the narrowest canyons, north/south-facing buildings the If we take the south-facing units in the H/W 1.5 canyon sunshine onlargest a winter day. need As winters are very often overcast with the same distribution of the relative energy performance oftend the offices. The single in housing is heating. This means The explanation is in the seasonal changes that happen through sity on energy consumption is more moderate for housing than for distributed increase in energy use along with increases in the H/W 2

2

to favour the the upper levels, which a lot better the units. Within overall pattern ofperform higher energy use at than the bot-

the If narrowest we the south-facing inbottom the 1.5 canyon. canyon ratioyear. and the position of the unitsnorth/south-facing closer to the of the lower levels, totake such a degree as to units increase theH/W overall perfortom of the canyons, buildings tend mance East/west-facing buildings show a more evenly to favour the upper levels, which perform athat lot happen better than the The significantly. explanation is in the seasonal changes through lower levels, to such degree as along to increase the overall perfordistributed increase inaenergy use with increases in the H/W the year. If we take East/west-facing the south-facing units in the H/Wmore 1.5 canyon mance significantly. buildings show a evenly ratio and the position of the units closer to the bottom of the canyon. distributed increaseis in energy use along with increases in the H/W The explanation in the seasonal changes that happen through ratio and the position of the units closer to the bottom of the canyon. the year. If we take the south-facing units in the H/W 1.5 canyon The explanation is in the seasonal changes that happen through the year. If we take the south-facing units in the H/W 1.5 canyon

200 lx, which is the threshold value of this model. light levels well below 2000 lx, the sky dome does not contribute

offices. The largest single need housing is lighting heating. This means Figs.quantitatively, 12 and 13 show thein relative impact of increased denmuch, to that establishing indoor levels above 200 which is the threshold this model. 4.3. Energy consumption for housing sity lx, on energy consumption is value more of moderate for housing

than for offices. The largest single need in housing is heating. This means 4.3. Energy consumption for housing

Figs. 12 and 13 show that the relative impact of increased density on energy consumption is more moderate for housing than for Figs. 12 and 13 show that the relative impact of increased denoffices. The largest single need in housing is heating. This means sity on energy consumption is more moderate for housing than for offices. The largest single need in housing is heating. This means

Fig. 11. Primary energy consumption for artificial light (kWh/m2 /year) for a 5-storey office building (north/south) as a function of urban density.

Fig. 11. Primary energy consumption for artificial light (kWh/m2 /year) for a 5-storey office building (north/south) as a function of urban density.

Fig. 11. Primary energy consumption for artificial light (kWh/m2 /year) for a 5-storey office building (north/south) as a function of urban density. 2 2 Fig. 11. Primary energy consumption for artificial light (kWh/m /year) a 5-storey office building (north/south) as adensity. function of urban density. Fig. 11. Primary energy consumption for artificial light (kWh/m /year) for a 5-storey officefor building (north/south) as a function of urban Fig. 11. Primary energy consumption for artificial light (kWh/m2 /year) for a 5-storey office building (north/south) as a function of urban density.

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Fig. 12. Total primary energy consumption (kWh/m2 /year) for housing as a function of urban density (note: energy consumption for artificial light is not included in total primary energy consumption for housing [25]).

that the heating contribution from solar radiation is an essential element for housing – unlike for offices, in which illumination level is the most important parameter. For example, the energy consumption varies by 11.2 kWh/m2 /year, from a north to a south orientation for a free horizon, due to variations in solar access (Fig. 12). However, the denser the city becomes the smaller the variation in passive solar gains. The relative deviation of the total energy consumption from free horizon to a height/width ratio at 3 varies from between +2% and +19% for housing (Fig. 13). The relative development of individual needs for heating and cooling is approximately the same for housing as for offices. The energy consumption for lighting is also more uniform across the city’s density. This is due to the consumer pattern, where the number of hours with a need for lighting in housing falls in the periods with a global illuminance level less than 200 lx. During winter, the most active hours of a housing unit occur in the morning and evening while it is still dark and artificial light is turned on. The energy variation over the individual floors is more uniform for housing than for offices. This is partly due to the relatively smaller variation in overall energy consumption. The north-oriented deviates from the other orientations by having a maximum variation of 4.5%. This rather low variation is due to the limited amount of solar radiation the units receive. Furthermore, the energy consumption for lighting is not part of the variation. What becomes apparent is the way that consumption is more dependent on use patterns and material and geometrical patterns other than urban density. Since the model design for this study

reflects a ‘9 to 5’ working life for the occupants, with apartments not being occupied in the daytime on weekdays, the hours where there is most activity are when the influence of solar radiation and daylight on the energy budget is minimal. Because heating is the dominating parameter on the energy budget for housing, should future housing be developed using the passive strategy of large south-facing windows to make the most of solar gains? Should heating be the dominant object for design of housing in general? At high latitudes as in northern Europe, solar gains are only available for the top storey in dense urban areas in the winter season, and even for the top storey it is drastically reduced compared to unobstructed solar access as shown in Fig. 10. This traditional passive solar design seems to have limited potential as a design strategy under these conditions, but because solar gains nevertheless play a discernible but minor role for lower storeys facing east, west and south, diffuse radiation reflected off opposing fac¸ades and the sky can be identified as the energy issue to design for. Overshadowing in dense cities is close to inevitable at these latitudes, but light redistribution through the reflectivity patterns of fac¸ades seems an interesting design possibility. One can imagine and indeed observe how temporal patterns of reflected light and heat can be redirected by fac¸ade sections at oblique angles to the sun. Heating is easily produced and maintained at a quality that satisfies bodily needs regardless of the combination of radiation, convection and conduction measures used. There is plenty of design potential, both technically and metaphorically, in addressing the human need for thermal stimulation. Light is much more difficult to

Fig. 13. Relative deviation (%) of energy consumption for a 5-storey housing building as a function of urban density compared to free horizon.

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reproduce in qualities and quantities that are anywhere near that of daylight, though artificial lighting offers interesting design opportunities. With this point in mind, and remembering that access to daylight and environmental variety affect human comfort and health in multiple ways, it is suggested that rich and varied daylight remains the main design priority in housing, though its direct contribution to the energy budget is smaller than heating. 5. Conclusions The study has given a detailed analysis of the distribution of solar radiation and daylight in a range of urban canyons reflecting different urban densities and demonstrated how this distribution affects the total energy use for heating, cooling and artificial lighting on different storeys of low-energy buildings facing the urban canyon, depending on orientation. It was found that the geometry of urban canyons has a relative impact on total energy consumption, compared to unobstructed sites, in the range of up to +30% for offices and +19% for housing, indicating that urban geometry is a key factor in energy use in buildings. From the given specifications of the building layout, it is possible on a free horizon to design a low-energy office building with an energy consumption of around 50 kWh/m2 /year. If the context around the building over time transforms into a dense urban area, the energy consumption will increase proportionally to approximately 70 kWh/m2 /year, resulting in a relative increase in energy consumption of up to 30% depending on orientation. As a consequence any building project in the making, whether new-build or refurbishment, would be advised to integrate not only a detailed simulation of the energy impact of the context as it is, but also an estimate based on the maximum density allowed on neighbouring sites. In urban master planning, it becomes critical to define ways to control solar access as a common good, not least for the effect it has on the experiential qualities of public spaces. New developments should be carefully screened for their impacts on neighbouring buildings and the public spaces they participate in creating. As the relative impact of urban density varies with both height and width of the urban canyon, it can be argued that the design of future energy optimized fac¸ades should be able to respond in a differentiated way to the issues posed by the distribution patterns of radiation in the urban canyon. Our investigation showed that reflected light makes an important contribution to the energy consumption of buildings, and is indeed the greatest fraction of daylight available to housing and offices on the lowest floors in high urban densities. The distribution of daylight in the urban canyon is more complex than previous studies have indicated, and the way that not only light, but also the heat carried with it, is distributed is very dependent on the reflectivity of building fac¸ades. What this highlights is that in northern Europe, building fac¸ades should not only be considered as selective devices so as to create optimum internal environments, but also in terms of their contribution to creating good and varied daylight conditions for neighbouring buildings. As Oke [26] says, there are “almost infinite combinations of different climatic contexts, urban geometries, climate variables and design objectives. Obviously there is no single solution, i.e. no universally optimum geometry”. Nevertheless, there are optimum ranges of geometric conditions in urban design – if we want to design energy efficient cities, urban spaces, workplaces and dwellings that have an intimate connection to the qualities of the natural environment. The artificial environments generated by energy use are something else, not necessarily worse or without design appeal, but something else, and these environments become dominant with the increase in urban density, and the influence of the natural environment diminishes. But what is optimal, or just “what is good”, is at heart a qualitative question, a question of values.

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Appendix A. Office Construction Exterior walls U-value Roof U-value Ground-contact/exposed floor U-value Internal walls U-value Internal ceilings/floor U-value Window U-value g-Value Visible light normal properties Use of the building Service, occupants Internal gains People Internal heat gain Lighting Lighting level Maximum power Installed power density Luminous efficacy Variation profile Switched-on-percentage Dimming profile Miscellaneous Maximum sensible gain Variation profile Air exchanges Infiltration Min flow Variation profile

Housing

0.2 W/m2 K 2

0.2 W/m2 K

0.15 W/m K

0.15 W/m2 K

0.15 W/m2 K

0.15 W/m2 K

2

0.35 W/m2 K

2

0.32 W/m K

0.32 W/m2 K

1.5 W/m2 K 0.62 0.68

1.5 W/m2 K 0.62 0.68

8 am–5 pm, M-F

On continuously

4 W/m2

1.5 W/m2

200 lx 4 W/m2 2 W/m2 /100 lx 50 lm/W 8 am–5 pm, M-F

200 lx 8 W/m2 4 W/m2 /100 lx 25 lm/W 6 am–9 am and 3 pm–10 pm 20% Manuel/on-off (200 lx)

0.35 W/m K

100% Dimming, (200 lx)

6 W/m2 8 am–5 pm, M-F

3.5 W/m2 On continuously

Day, 0.13 l/s m2 Night, 0.09 l/s m2 Day, am–5pm, M-F Night, outside working hours

0.13 l/s m2 – – –

Mechanical ventilation Min flow 0.9 l/(s m2 ) Variation Profile 8 am–5 pm M-F System specific fan 2.1 W/(l/s) power (SFP) Vent. heat recovery 65% effectiveness Cooling efficiency COP = 2.5 Natural ventilation Max flow – Variation profile – Heating and cooling Winter season (timed, week 01–18 and 38–53) Heating set point 20 ◦ C (working hours) 16 ◦ C (outside working hours) Cooling set point 24 ◦ C (working hours) Off (outside working hours) Summer season (timed, week 19–37) Heating set point 23 ◦ C (working hours) 16 ◦ C (outside working hours) Cooling set point 25 ◦ C (working hours) Off (outside working hours) Hot water consumption 100 l/m2 /year

0.3 l/(s m2 ) On continuously 1.0 W/(l/s) – COP = 2.5 0.9 l/s m2 , t > 25 ◦ C Weeks 19–37

20 ◦ C (on continuously) – 25 ◦ C (on continuously) –

23 ◦ C (on continuously) – 26 ◦ C (on continuously) –

250 l/m2 /year

Journal Identification = ENB

2020

Article Identification = 3187

Date: May 21, 2011

Time: 10:31 am

J. Strømann-Andersen, P.A. Sattrup / Energy and Buildings 43 (2011) 2011–2020

References [1] T.R. Oke, Boundary Layer Climates, Routledge, 1978. [2] K. Steemers, Energy and the city: density, buildings and transport, Energy and Buildings 35 (2003) 3–14. [3] Erhvervs- og Byggestyrelsen, Strategi for reduktion af energiforbruget i bygninger, (n.d.). [4] V. Geros, M. Santamouris, S. Karatasou, A. Tsangrassoulis, N. Papanikolaou, On the cooling potential of night ventilation techniques in the urban environment, Energy and Buildings 37 (2005) 243–257. [5] C. Georgakis, M. Santamouris, Experimental investigation of air flow and temperature distribution in deep urban canyons for natural ventilation purposes, Energy and Buildings 38 (2006) 367–376. [6] P. Littlefair, Daylight, sunlight and solar gain in the urban environment, Solar Energy 70 (2001) 177–185. [7] C. Ratti, N. Baker, K. Steemers, Energy consumption and urban texture, Energy and Buildings 37 (2005) 762–776. [8] N. Baker, K. Steemers, LT method 3.0 – a strategic energy-design tool for Southern Europe, Energy and Buildings 23 (1996) 251–256. [9] N. Baker, K. Steemers, Energy and Environment in Architecture, 1st ed., Taylor & Francis, 1999. [10] D.H. Li, G.H. Cheung, K. Cheung, J.C. Lam, Simple method for determining daylight illuminance in a heavily obstructed environment, Building and Environment 44 (2009) 1074–1080. [11] P.A. Sattrup, J. Strømann-Andersen, Sustainable cities: density versus solar access? A study of digital design tools in architectural design, in: ISES Solar World Congress 2009 Proceedings, Johannesburg, South Africa, ISES, 2009. [12] A. Rossi, The Architecture of the City, The MIT Press, 1984. [13] D. Hawkes, The Environmental Tradition: Studies in the Architecture of Environment, 1st ed., Taylor & Francis, 1995.

[14] D.B. Crawley, J.W. Hand, M. Kummert, B.T. Griffith, Contrasting the capabilities of building energy performance simulation programs, Building and Environment 43 (2008) 661–673. [15] G.W. Larson, R. Shakespeare, Rendering with Radiance, Morgan Kaufmann, 1998. [16] C. Reinhart, P.F. Breton, Experimental validation of Autodesk (R) 3ds Max (R) Design 2009 and Daysim 3.0, Leukos 2009 (2009) 7–35. [17] C.F. Reinhart, O. Walkenhorst, Validation of dynamic RADIANCE-based daylight simulations for a test office with external blinds, Energy and Buildings 33 (2001) 683–697. [18] C.F. Reinhart, S. Herkel, The simulation of annual daylight illuminance distributions – a state-of-the-art comparison of six RADIANCE-based methods, Energy and Buildings 32 (2000) 167–187. [19] A. Nabil, J. Mardaljevic, Useful daylight illuminances: a replacement for daylight factors, Energy and Buildings 38 (2006) 905–913. [20] C. Reinhart, J. Mardaljevic, Z. Rogers, Dynamic daylight performance metrics for sustainable building design, Leukos (2006). [21] Danmarks Statistik/Statistics Denmark, Statistisk Årbog 2009, 2009. [22] C. Ratti, D. Raydan, K. Steemers, Building form and environmental performance: archetypes, analysis and an arid climate, Energy and Buildings 35 (2003) 49–59. [23] EN 15251. Indoor environmental input parameters for design and assessment of energy performance of buildings addressing indoor air quality, thermal environment, lighting and acoustics, 2007. [24] CIBSE Guide A, Environmental Design, 1999. [25] EBST, Bygningsreglemet for erhvervs- og etagebyggeri, National Agency for Enterprise and Construction, Copenhagen, Denmark, 2010. [26] T. Oke, Street design and urban canopy layer climate, Energy and Buildings 11 (1988) 103–113.

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Summary

Integrated Energy Design of Large-Scale Buildings Summary of PhD thesis by Michael Jørgensen The hypothesis of the project is that design choices such as geometry, orientation and organisation made in the early concept stage have a large impact on energy consumption, indoor air quality and building economy. The objective of the PhD thesis is to examine the influence of building geometry on the total energy consumption and the indoor air quality. In addition, the thesis looks into how to integrate knowledge on building physics in the early stages of design. The thesis presents the results of three years’ research where focus has been on the early collaboration between architects and engineers in the first weeks of the concept development. This is when design decisions in relation to volume, orientation and materials are taken. In order to apply the energy performance of the building as an active design tool, the PhD project suggests that there is a need for new methods, strategies and technologies to support and guide the architect in the process towards making design decisions which reduce energy consumption without compromising on comfort, economy or aesthetics. The thesis identifies the engineering experience gained through a number of design projects where engineering know-how has been implemented in the design process in various ways.

In addition, the thesis documents the knowledge gained through simulations of geometry and daylight on large-scale buildings. Geometry has a large influence on the total energy consumption of a building. The building geometry primarily determines the amount of solar energy that hits the building. By optimising the building geometry in relation to function and solar energy, the thesis documents a possible energy reduction of 30-50 %. Studies of three buildings illustrate that the daylight strategies formulated by architects and engineers in the early design process correspond with the users’ experience of the buildings after completion. Further, the studies show that daylight strategies based on spatial considerations receive more positive feedback than daylight strategies aiming for 200 lux. The conclusion of the thesis is that simulation tools can provide important and detailed information on daylight and can be used to evaluate different solutions. However, simulations should not be carried out until after the design strategy for use of light has been established. In this connection, it is essential that the engineer understands and applies the spatial qualities of daylight.

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INVESTIGATION OF ARCHITECTURAL STRATEGIES IN RELATION TO DAYLIGHT AND INTEGRATED DESIGN— A CASE STUDY OF THREE LIBRARIES IN DENMARK Michael Jørgensen,1 Anne Iversen,2 Lotte Bjerregaard Jensen3

INTRODUCTION This paper investigates the use of daylight in three architecturally successful buildings. The aim is to discuss the challenges and opportunities of architectural daylight strategies in relation to integrated design. All these buildings were designed with the focus on a strategy of using daylight to create well-lit, exciting spaces and spatial sequences. The original ideas, thoughts, and decisions behind the designs and daylight strategy are compared with answers in questionnaires from test subjects who have experienced the space and lighting conditions created. The results indicate that the architectural daylight strategies formulated by the architects and engineers at the beginning of the design process are actually experienced by the “users” in the existing buildings. The architectural daylight strategy was different in each of the three libraries, and analysis of the results shows that daylight strategies that include spatial considerations received more positive evaluations. Furthermore, the study showed that designs aimed at achieving an even distribution of daylight with an illuminance target of 200 lx did not result in higher evaluation of the daylight design. KEYWORDS daylight, integrated design, work methods

DAYLIGHT STRATEGIES IN RELATION TO INTEGRATED DESIGN A good daylight design can create dynamic and interesting interiors that enhance spatial awareness, productivity, and well-being, while a poor daylight design can cause discomfort and require excessive use of energy. A good daylight design depends on finding a balance between the need for light, the local climatic conditions, and the architectural vision and idea. In connection with integrated design, the use of daylight is a central element and plays an important role in realizing high-performance buildings in which the quality and amount of daylight is directly related to user satisfaction and the energy used for lighting, heating, cooling, and ventilation (Leslie, R. P. 2003). 1

Phd student, Department of Civil Engineering, Technical University of Denmark, Brovej, Building 118, DK-2800 Kgs, Lyngby, Denmark. Phone: +45 45251934; fax: +45 45931755; e-mail: mijo@byg.dtu.dk 2 Author information. 3 Author information.

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Several studies have shown that the energy use for lighting accounts for approximately 10–50% of the total energy consumption of a residential or office building. We can assume that the energy consumption for lighting is probably larger in the case of cultural buildings with longer opening hours. Crucial decisions in relation to reducing a building’s energy consumption are also taken in the earliest design stages—which are typically managed by architects (Baker, N. 2000). In the early stages of the design process, the architectural idea is conceived and formulated. The functional layout of the rooms, orientation, the overall geometry of the building, and finally the glazing area, shape, and position, are all determined based on this idea. It is also in the early stages of the design process that architects usually consider the amenity value of daylight. Scandinavian architecture has a strong tradition of less formalistic design in comparison with other traditions, which means designing from the inside and out. An architect educated in the Scandinavian tradition often considers daylight from the first sketch. Alvar Aalto’s Villa Mairea (1930) is a prominent example, where the light that exists between the slim trees of a pine forest was the very first inspiration for the architectural design and was maintained in the design of the foyer area and a number of other places in the building. The main objective of integrated design is to improve the overall quality of buildings, in terms of energy demand, indoor environment, economics, and user satisfaction (Intelligent Energy, 2006). To this end, the application of simulation tools has become increasingly important in the analysis and evaluation of various parameters and how they affect the daylight conditions and energy demand for the space and building being considered. The application of these advanced tools is typically handled by the engineer, while spatial considerations are typically handled by the architect, so there is a risk that daylight strategies are considered solely in terms of either aesthetic purposes or functional requirements (Baker, N. and Steemers, K. 2002). But if integrated design is defined as a process informed by interdisciplinary knowledge, the formulation and application of daylight strategies must include both spatial aesthetics and considerations concerning energy reductions and indoor environment. This implies that working with daylight is a field where there is great potential for architects and engineers to work together to achieve synergy and positive effects. The overall aim of this article is to discuss the challenges and opportunities of architectural daylight strategies in relation to integrated design. The article revolves around three buildings, each of which was designed with the focus on a strategy of using daylight to create well-lit, exciting spaces and spatial sequences. The original ideas, thoughts, and decisions behind the designs and daylight strategy are compared with answers in questionnaires from test subjects who have experienced the spaces created. We measured the lighting conditions with the aim of investigating the architectural strategy and the correlation between the strategy and how it is perceived. Library buildings are the focal point in this paper. Libraries have strict functional requirements with regard to illuminance levels so people can find and read books and the building can function as a place of work and study. Secondly, libraries play a special cultural role in society and are typically seen as an important priority for local authorities, not only as a place to acquire knowledge and experience, but also as an arena for culture in its broadest sense. Libraries provide a social meeting place comprising many facets and opportunities, and because of this multifaceted role, architects have always seen libraries as an opportunity to create a special spatial experience for their visitors and users. The three libraries presented in this paper were designed over a period of almost 30 years, and they are characterized by the way

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they were designed at the time. They are all considered to have a high-quality architectural daylight design—making it possible to investigate the design process in relation to daylight. METHOD A shift is currently taking place in the lighting research community from traditional quantitative approaches toward a more human-oriented approach, which is beginning to combine various scientific approaches to widen our understanding of the potential daylight has for us humans (Wang, N. 2011), (Parpairi, et al. 2002). This study explores that trend, gathering information from several different approaches. It consists of three parts: 1. The architectural daylight design was investigated and described through the original drawings and competition documents from the time of the design and through semi-structured interviews (Yin, R. K., 2009) with the architect responsible for the architectural design. 2. We carried out a survey of 35 engineering students that visited all three buildings on November 5, 2010, to obtain their subjective evaluation of the lighting conditions. Our focus for the investigation was on the light conditions in the space, both electric and daylight. The students were asked to enter the room, walk around, and after ten minutes fill out a questionnaire. The questionnaire contained eight questions on the brightness of the room, the variation between light and dark areas, and various openended questions about the architecture and the use of space. 3. At the same time, luminance measurements were taken to quantify the overall lighting conditions. High dynamic range (HDR) photography (Inanici, M.N. 2006) was used to capture luminance data in various directions. An Olympus E-510 D-SLR digital camera fitted with an EZ-1442 14-42mm 1:3.5-5.6 lens on a tripod was used to capture images with multiple exposures ranging from –5 to +5 EV. These images were combined into the HDR images using Photosphere software (Ward, G., 2011). The advantage of this technique is the achievement of a luminance mapping of the entire view within a couple of minutes. For each luminous scene, a calibration factor was determined by dividing the pixel digits of a given area assessed by using the HDR technique by the monitored luminance value measured by Hagner. This approach has been reported to provide accurate results in scenes with large luminance contrasts (Borisuit, A 2010). Illuminance measurements were taken at specific locations in the space, combined with continuous measurements of outdoor illuminance to calculate the daylight factor and monitor the changing sky conditions. During the measurements, the sky conditions varied from sunny to cloudy. INVESTIGATION OF ARCHITECTURAL DAYLIGHT STRATEGIES Gentofte Library The central library in Gentofte is the oldest of the three buildings and was designed and inaugurated in 1985. It was designed by the famous Danish architect Henning Larsen (HL) (1925) and is considered an example of the Scandinavian modernist tradition. The library has two main entrances, one to the south and one facing the nearby park to the north. The building has a total gross floor area of 7300 m2 divided between three levels: ground floor (3000 m2), first floor (1900 m2), and basement (2400 m2).

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FIGURE 1. Three pictures showing the form and interior space of Gentofte Central Library.

The library has a flat roof and is basically square. The south façade is relatively closed, with small window bands on each floor. The north façade is open and consists mainly of glass facing the adjacent park. In the centre of the building, there is a large double-height atrium. Here the daylight penetrates through nine large circular skylights and through a hidden vertical window band along the edge of the atrium ceiling. The atrium acts as a daylight-lit semipublic square (Figure 1). The first floor is designed as a balcony around the central space, from where there is also access to the enclosed reading rooms, staff canteen, and administration. The architect responsible for the design, Henning Larsen, has distinguished himself both in Denmark and abroad as a visionary architect, especially recognized for the Foreign Affairs building in Riyadh. During his long professional life, he always said that daylight was the main inspiration for his architectural creations. He emphasized that he always considered daylight from the very first instant, even during the programming phase, and that his design process mainly revolved around a series of small cardboard models of spaces. He explains how he modelled the daylight architecturally by ‘dreaming’ daylight, working at the drawing table, and that the investigation of daylight was done through cardboard models and an adjustable drawing table lamp. In Henning’s view, human beings have both intellect and senses and should design accordingly. In his own words: “The architect constantly imagines how it will be perceived by people walking from one space to another. The architect tries to sharpen his senses, feel with his body while designing. If you build a cardboard model, you involve your hands, eyes, ears— all your senses. It is a holistic experience to build a soft mock-up. Computer programs do not involve your body and all your senses. We have always worked with models. It has been the main design tool of architects for thousands of years. They do not have to be nice models.” Architectural daylight design Henning Larsen explains that the daylight design in Gentofte library was not subjected to any daylight calculations during the design process. The design was made purely by intuition and experience. He never felt uncertainty or any need to know more precisely how much light would enter a room—and he never received any complaints about the daylight—on the contrary. When asked whether he placed the large glazed area in Gentofte library facing north to avoid overheating during the summer, he explains that he synthesized several different considerations, but it was not explicitly to avoid overheating. The view of the park, the sense of ‘street’ leading out into the open, etc., were more important to him. HL explains that daylight has always interested him more than walls and floors and the like, because daylight is what controls how people move through spaces. Daylight is what makes the space unfold and makes you feel at ease in it. Daylight intensity establishes a kind

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of hierarchy reflecting the importance and function of a space. He wanted to create certain atmospheres, special places within the library by means of differences in daylight intensity. Questioned about what sort of ideas inspired the daylight design and architecture of Gentofte Library, Henning Larsen hesitates, but goes on to explain that it is difficult to talk about where these things really come from. His initial sketches involved some skylights, because the site is completely flat and the building regulations limited the large building to two stories above ground. What was mainly on HL’s mind at the beginning of that project was the organization of the space in the library. For him, the focus was on creating a large central space with skylights in the geometrical shape of a square. The square should attract all attention by having intensive daylight—not only from the skylights but also from apertures along an elevated part of the roof over the double-height space. This space should contain all the books. The other functions in the library were located more ad hoc with small office spaces, etc., towards the periphery of the atrium room. What was important to HL was that the diffuse light from a north-facing aperture should not compete with the direct sunlight in the central atrium. He explained that he did not think in terms of a complete daylight strategy, and that a project is like one big package that you slowly unwrap—daylight, functions, organization. It evolves gradually and builds on experience from previous projects. From our interview and from our investigation of the original drawings and documents from the time of design, we can argue that the main daylight strategy of the library was that users should be attracted by the intensity of light. The light should be an attractor. At Gentofte library, you enter through a dark enclosed space and are attracted by the large daylight-lit atrium with the books. Another example of an attractor is the large glazed area facing north to the park. His main goal was to achieve a multiplicity of nuances in daylight. Evaluation of lighting conditions With the electric lights turned on, the questionnaire tells us that the central atrium space is perceived as bright with a weighted mean of 0.46 on a scale from 0 (bright) to 1 (dark) and that the distribution of light throughout the space is perceived as even with a weighted mean of 0.38 on a scale from 0 (even) to 1 (uneven). To the open-ended questions, we received comments like “the skylight surrounding the atrium helps define the large room” and “the oval skylights in the centre of the room work really well to guide people to the information and reception area as well as providing a comfortable lighting level”. If we compare the illuminance measurements in the two situations, measured at the same location, the light levels drop from 646 lx to 355 lx when the electric lights are turned off. But when we compare the results from two questionnaires, one with the electric lights turned on and the other with them off, it is noticeable that there were no significant differences in the responses when the subjects were asked whether they perceived the space as bright or dark on a scale from 0 (bright) to 1 (dark). However, when the electric light was turned off, the distribution of light in the space changed and was now perceived as more uneven with a weighted mean of 0.5 on a scale from 0 (even) to 1 (uneven) compared to 0.38 when the electric light was on. This is supported by the comments received when subjects were asked open-ended questions about the use of the space, and how the lighting design supports the architecture. Comments included: “In the double-height space, the daylight works well. The great contrast to the sides, where it is darker, makes the central space more prominent” and “there are no great differences between the lighting levels in the centre of the space, but when the electric lights are turned off, the 44

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FIGURE 2. False colour images showing the luminance difference, Cd/m2. Electric lights On

Electric light Off

areas below the balconies are now clearly darker.â&#x20AC;? Luminance measurements taken at the time support the subjective evaluation, showing reduced luminance below the balcony, while the luminance levels on the floor in the atrium remained the same (Figure 2). During the investigation, the outdoor illuminance was stable at around 6000 lx. Conclusion, Gentofte During our interview, HL explained that the architectural approach to the use of daylight was to create lighting experiences that would attract users, for example, to stay in specific areas or to move through the building in a certain way. He described how he worked with cardboard models and intuition to create two distinct attractors, a strong top-lit central atrium space, and a large glazing area to the north in close connection to the nearby park. These two elements together were to provide a general interior overview and create a transparency along walk lines, walls, and between the bookshelves, and ensure that you would not feel enclosed. We can conclude from our measurements and answers to the questionnaire that the architectural daylight strategy was realized and experienced by the subjects. From a quantitative point of view, the illuminance levels are sufficient for the function of the library, and when the electric light is turned off, the illuminance levels stay above 300 lx with no significant difference in the subjective evaluationâ&#x20AC;&#x201D;indicating that the atrium space functions without any additional electric lighting. We can conclude that HL was able to achieve a nuanced daylight design using only cardboard models, his intuition and experience, indicating that it is possible to achieve a good daylight design without the use of simulation tools or calculation of daylight levels.

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FIGURE 3. Three pictures showing the interior space and exterior of Albertslund Library.

Albertslund Library Albertslund Library was originally designed by the Danish architectural company, Fællestegnestuen, and was a part of a large urban master plan that comprised the library, the local authority administration, a cinema, and a music venue. The original library was a typical Danish building from the seventies with a flat roof, small windows, and visible technical installations. After several years of use, it had a number of big constructional problems. In fact, the building was in such a bad shape that it was necessary to undertake a complete reconstruction. The library owner, Albertslund Town Council, had high requirements with regard to energy efficiency and sustainability for the “new” library. Henning Larsen Architects chose early on to enter into a partnership with Esbensen Consulting Engineers due to their experience of integrated design and collaboration with the architect from the first sketch. The new library is roughly the same size as the original one, with a total floor area of 3000 m 2. The building is a large rectangular volume with large window areas facing south and north. With a minor extension to the southwest, a protruding lower part of the south façade including a balcony and distinctive transverse serrated skylights, the new library achieved its own unique architectural expression (Figure 3). Today, the library is regarded as one of the first examples of integrated energy design in Denmark, where the design team focused throughout the design process on using simulation tools to optimize daylight conditions and design for natural ventilation and a good thermal environment (Nielsen, B. et al. 2006). Architectural daylight design Esbensen Consulting Engineers had already taken part in a European research project about integrated design and had chosen Albertslund as a case study to apply and test the integrated design method. When we looked at the original design documents and interviewed the engineer and architect responsible, it was clear that quantitative objectives were formulated in relation to illuminance levels, thermal indoor environment and energy efficiency, in accordance with the guidelines prescribed for integrated design (Löhnert G. et al. 2003). The quantitative daylight aim was to obtain a high level of illuminance exceeding 200 lx in most of the library space under CIE overcast sky conditions and achieve an even daylight distribution without glare problems and thus save energy for lighting and cooling. In our interview with the architect responsible, Frans Drewniak (FD), he confirmed that evenly distributed daylight was conceived by the designers as a quality, because it made the daylight-lit space flexible with regard to function, and that several window solutions had been investigated with a view to achieving this goal. The final solution was a skylight design evenly spaced over the entire length of the library. The skylight was an elevated box-shape with windows 46

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FIGURE 4. Graphic illustration showing the final skylight design (Henning Larsen Architects).

to the sides and a closed roof (Figure 4). The design was thoroughly analysed in a series of daylight and thermal simulations, based on which integrated constructive solar shading in the box-shaped skylight was developed and implemented. Although the evenly daylight distribution was conceived as a desirable quality, FD feared that the uniformly distributed daylight might be perceived as cold and monotonous, so he designed several features to counteract this possibility. Firstly, the skylights were optimized to allow a streak of direct sunlight to penetrate through the windows and blinds, thus bringing life and rhythm to the room. Again simulation tools were used to optimize the “streak of direct sunlight” so as not to affect the indoor thermal environment and cooling demand. Secondly, they chose a reddish, warm colour for the floor covering and dark grey book shelves to avoid the space being perceived as cold. Evaluation of lighting conditions The architectural daylight strategy in Albertslund Library focused on a quantitative goal—to achieve a certain illuminance level and distribution of daylight throughout the length of the rectangular library space. When we analysed the results from the questionnaire, the lighting conditions with electric lights turned on were evaluated as bright with a weighted mean of 0.4 on a scale from 0 (bright) to 1 (dark). When subjects were asked whether they perceived the lighting conditions as even or uneven, they gave a similar result with a weighted mean of 0.4. Illuminance measurements with the electric lighting on show the average illuminance in the area is 396 lx—indicating that, when electric light is turned on, the light levels are more than sufficient to read and work and that the light levels are certainly high enough to provide good vision. When subjects were asked whether the lighting design supported the architecture, we received comments like: “It could be solved in many different ways, but I do not know if it actually supports the architecture. But the interior is adapted to the skylight” other comment were: “The light somehow looks uniform in the room, so it is hard to say how much the skylight gives compared to the artificial light” and “I think there is good uniform light all over, especially by the bookshelves, so you can easily find what you are looking for” and “The lighting design does not highlight anything; it is very similar in the whole area”. When subjects were asked if the lighting design supported the use of the space, we received comments like: “The daylight distribution is very even and there is no direct sunlight in the main part of the library. The reading area close to the windows is better lit and “invites” reading. The colour of the floor makes the room seem warm”.

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FIGURE 5. False colour images showing the luminance difference, Cd/m2. Electric lights On

Electric light Off

When the electric lights were turned off, subjects perceived the space as darker, with a weighted mean of 0.7 on a scale from 0 (bright) to 1 (dark). The lighting conditions were perceived as uneven with a weighted mean of 0.6 on a scale from 0 (even) to 1 (uneven). When subjects were asked whether the variation in light levels was too great or too little, the result was a weighted mean of 0.4 on a scale from 0 (too great) to 1 (too little). It should be noted that at the time the electric light was turned off, the outdoor illuminance had dropped significantly from 6000 lx to 3000 lx. This reduction in illuminance can explain why the room was perceived as dark when comparing the two situations. When subjects were asked again whether they thought the lighting design supported the use of the space, we received comments like: “It’s a bit dark everywhere” and “the dark book shelves and wall, together with the grey colour of the ceiling makes the room darker.” The results showed that in general the subjects gave answers in the middle of the range. Illuminance measurement taken while the electric lights were turned off, showed that although the illuminance level was reduced from 396 lx to 196 lx and the outdoor illuminance was only 3000 lx, much lower than CIE overcast condition, used in the daylight simulation tool and as basis for the design and optimization, the illuminance level still met the quantitative aim of 200 lx. Conclusion, Albertslund From a purely design point of view, it is clear that the design and placement of windows were influenced by the quantitative strategy of achieving a certain illuminance level that could replace electric light with daylight, while minimizing the passive solar heat gain from the 48

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increased window area in the roof. The design documents and our interview with the architect and engineer support the conclusion that Albertslund really was a project conceived in an integrated design process and that the design process was informed by energy and daylight simulations. During the design process, there was no particular focus on using the daylight as an attractor or to apply focus to a particular area as was the case in Gentofte. From our measurements, we can conclude that the design team achieved their goal of supplying enough daylight, even under a severely overcast sky. But the test subjects perceived the space as dark and uneven when the electric lights were turned off, even though there was plenty of daylight from a quantitative point of view. Their comments indicate that they could see and understand that the strategy behind the evenly distributed skylights was to provide an even distribution of daylight, but that the light conditions were perceived as uniform, with no clear distinction between daylight and electric light. We can conclude that the subjective evaluation of the lighting conditions at Albertslund showed no improvement over Gentofte. Frederiksberg Library Frederiksberg Library consists of two buildings. The old library and a new expansion located below ground level. The expansion was inaugurated in 2004 and was a part of the first-prize proposal for an urban development and master plan for the centre of Frederiksberg won by Henning Larsen Architects in 2000. Access to the underground library is through the original main entrance and the extension is connected by a large stairway in the hall of the old library. This stairway leads down to a large open space that contains a reading area situated on a plateau in the centre and a children’s library organized around it, connected by a ramp. Above the reading area, there is a large rectangular skylight matching the dimensions of the plateau (Figure 6). The colour of the walls and ceilings is white and the floor is a bright grey. The geometry of the library is defined by what was possible at the complicated site, which is penetrated by ductwork, etc. We selected this project because of its profound dependence on lighting and daylight. The local authority had to ‘sell’ the idea of an underground library at this site to the public, and access to daylight plays an essential role as the guarantee against associations with ‘dark’ cellars, etc. Architectural daylight design The architect responsible for the project was Ulrik Raysse (UR) from Henning Larsen Architects. In the interview, he described himself as a classical skilled architect, working in the Henning Larsen tradition. In his own words, his interest is the “old-school daylight quality and FIGURE 6. Three pictures showing the interior space and exterior of Frederiksberg Library.

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experience”, and he is inspired by the solid tradition for this approach in Danish architecture as manifested particularly thirty to forty years ago. He believes that daylight and spatial qualities are the pivotal points in the design process. UR does not use the diagrammatic approach which influenced the design process for Albertslund Library. He works with cardboard models early in the design process and regards them as an advanced and nuanced design tool. To him, the primary task of daylight is to create spaces. With daylight, the architect creates places where people can meet—social meeting places. As an example of how he works architecturally with daylight, he describes how he thinks of daylight as something that excavates the mass of the building and exposes a specific spatial quality. Daylight makes holes in the mass—i.e., social meeting places. Because of its difficult location below ground level, with the inherent risk of negative associations with “dark” cellars, it was decided early on to add large skylights to the library. From the design documents, we can see that the skylight was always located in relation to the reading area, but the number, position, and size of the skylights changed many times during the design process. The intention behind having a large top light over the reading area was to give an impression of openness towards the sky, inducing a feeling of sitting outside and reading in the open air, as opposed to sitting in a cellar with no view of the sky. To further nuance and soften the basic daylight strategy, several dim daylight areas were created in the spaces adjoining the central reading area. But still, the architects chose not to establish secondary daylight atriums, because they did not want to spoil the effect of the central skylight. UR describes the library as having a touch of being a staged experience, with daylight as the medium for the orchestration and used as a medium for creating a scenography. UR felt it was also important that the entire library be experienced at one glance when entering—“that all things ‘breathed’ the same light and air,” as he put it during the interview. This strategy was manifested in the strong effect of the centrally placed skylight over the reading area that became the final solution. The skylight is perhaps, in the architect’s own words, a bit too large in scale, but this was necessary to satisfy the architectural intentions described above. The skylight, and therefore also daylight, is the connecting and gathering architectural element. To stress this effect and to avoid competition with the skylight effect, the space itself is very low-key in terms of tectonics. For instance, the ceiling seems without details and as solid and simple as possible. This aim created a lot of extra work in integrating the necessary installations. FIGURE 7. Illustration showing a section of Frederiksberg Central Library (located below ground level) (Author).

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Evaluation of lighting conditions When we evaluated the use of daylight in this room, it was with particular focus on the plateau and the effect the skylight creates. However, it should be noted that electric lighting plays an important role in this library and it is clear that while the use of electric light is secondary, it was conceived simultaneously. So the electrical lights were on during the evaluation of the use of light in order to insure a fair discussion of the architectural daylight strategy. During the investigation, the subjects were all located on the plateau, looking in various directions.Our analysis of the results from the questionnaire showed that the test subjects perceived the ‘room’ as ‘bright’ with a weighted mean of 0.2 on a scale from 0 (bright) to 1(dark). When subjects were asked whether the lighting design supported the use of the space, we received comments like: “Yes, you do not feel that you are sitting underground. The feeling of claustrophobia is minimal, because the room is very bright” and “The skylight highlights the study-area in the centre of the room and therefore gives a stronger expression to this area. It is very suitable for study and reading.” Furthermore, with the electric light on, the test subjects perceived the distribution of light as even with a weighted mean of 0.3 on a scale from 0 (even) to 1 (uneven), which was further supported by a secondary question about the variation of light in the space. When the electrical lights were turned off, the test subjects no longer perceived the distribution of light as even. When asked whether the variation was too high too low, they replied that the variation in light was too high with a weighted mean of 0.2 from 0 (too high) to 1 (too low). Illuminance measurements were performed on the plateau in a rectangular pattern with the electrical lights turned on. The average illuminance on the plateau was calculated

FIGURE 8. False colour images showing the luminance difference, Cd/m2. Electric lights On

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Electric light Off

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to 1156 lx. It should be noted that during these measurements the outdoor sky conditions varied from partially cloudy to fully overcast, with an average outdoor illuminance measured at 6645 lx. The measurements support the questionnaire and show that light levels on the plateau were high even though the sky condition was overcast. Conclusion, Frederiksberg During the interview we asked UR if he believed that the idea behind the use of daylight was successful. He replied that during the summer, parasols are positioned on the reading platform—“giving a sense of being outdoors and protecting the readers from the strong direct sunlight that penetrates the skylight.” The purely architectural daylight strategy—which is more or less the only architectural idea in the project—carries the project through. The space is perceived positively by the users despite the less advantageous starting point of a location below ground level. From a quantitative perspective, the daylight is distributed too unevenly, with dramatic differences between the various areas in the library. This is soothed or ‘repaired’ by means of the electric lighting design. The space would not function without permanent electric lighting, and in this sense no attempt was made to replace electric light with natural daylight, nor has it been done, although it might have been possible in spite of the location below ground level. The interview exposed other severe problems that were not addressed in the daylight design. Considerations about the effect of artificial light and direct sunlight on the thermal indoor environment were clearly not part of the design process. The example of the parasols can be viewed from two positions: one that it supports the architectural idea, inducing a feeling of sitting outside and reading in the open air, or alternatively that the parasols are just temporary solutions to a severe problem in the daylight design that would probably have been exposed in an integrated design process and have resulted in the implementation of external shading. In spite of the shortcomings of the daylight design from a quantitative and integrated design point of view, the architectural daylight design is successful in framing and defining a central, semi-public indoor space. Conclusion In this study, we have examined some of the challenges and opportunities of architectural daylight strategies in relation to integrated design. From our questionnaire, interviews, and investigation of design documents, we found that the architectural daylight strategies formulated by the architects and engineers at the beginning of the design process were experienced by the “users” in the existing building. The architectural daylight strategy was different in each of the three libraries and analysis of the results shows that daylight strategies that include spatial considerations received more positive evaluations. Furthermore, the study showed that designs aimed at achieving an even distribution of daylight with an illuminance target of 200 lx did not result in higher evaluation of the daylight design. DISCUSSION When we compare the three libraries, it is clear that they were designed from three different approaches. Gentofte was designed exclusively with cardboard models and HL intuition and experience—and is a thoroughly designed project, where every window is carefully located relative to the main architectural daylight strategy. Albertslund Library was based on a com-

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pletely different strategy and design method. Here the focus was on flexibility and achieving a certain illuminance level without compromising the thermal environment. The engineers were clearly involved in the design process and it can be concluded that the strategy and design method succeeded in creating a bright library that meets the functional requirements. The geometric boundaries made Frederiksberg a totally different project. However, in terms of daylight strategy, the project relied on the same ideas as the library in Gentofte. In Frederiksberg, the architectural daylight strategy was to stage the central plateau and ensure that the light level here was so high that you felt you were sitting outside. UR felt that the primary function of daylight was to create “spaces” and he focused primarily on staging and exaggerating the amount of light on the plateau, which meant having one large central skylight. One criticism of the daylight design in Frederiksberg library is that the architect’s idea “won” over the rational use of skylights to create an evenly-lit library, which could have been achieved without competing with the large central skylight. Moreover, problems have been reported with the thermal indoor environment that could have been avoided if the skylight had been analysed using simulation tools. Our investigations show that daylight and artificial light are clearly linked to the subjective experience of spaces, but they are also physical parameters that decide whether we can see and read. The virtual simulation models used today have trouble achieving the same “feeling” that can be achieved when working with a cardboard model. The virtual model can often result in everything being seen from above and there is a tendency to forget to work with the detail and transitions. Albertslund and Frederiksberg are good examples in this respect. Simulation tools can provide important and detailed information with regard to the performance expected of a daylight design and can be used to evaluate various options. We are not suggesting that simulations should be omitted from the design process, but that simulations should be initiated after an architectural strategy for the use of light has been formulated and investigated using cardboard models. This means it is vital that the engineer can understand and work with the spatial qualities that exist in light. However, there is no formal design method or tool to harmonize these approaches to daylight design. What is clear is that a lot can be learned from studying examples where daylight has been used to create interesting, well-lit architecture. REFERENCES

Baker, N., and K. Steemers. (2002). Daylight Design of Buildings. James & James Ltd, 35–37 William Road, London, NW1 3ER, UK. Baker, N., and K. Steemers. (2000). Energy and Environment in Architecture. Spon Press, London. Borisuit, A., J. Scartezzini, and A. Thanachareonkit. (2010). “Visual discomfort and glare rating assessment of integrated daylighting and electric lighting systems using HDR imaging techniques.” Archit.Sci.Rev., 53(4), 359–373. Intelligent Energy. (2006). “Mapping of previous integrated energy approaches”, Part of work package no. 2 in the EU INTEND project—task 2.1. EIE-06-021-INTEND. Inanici, M. N. (2006). “Evaluation of high dynamic range photography as a luminance data acquisition system.” International Journal of Lighting Research and Technology, 38(2), 123–134. Leslie, R. P. (2003). “Capturing the daylight dividend in buildings: why and how?” Building and Environment, 38(2), 381. Löhnert G., A. Dalkowsk, and W. Sutter. (2003). “Task 23—Optimization of Solar Energy Use in Large Buildings—Sub Task B—Design Process Guidelines.”

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Nielsen, B., H. Sorensen, R. Pedersen, and F. Drewniak. (2006). “Albertslund Library, Denmark: Optimization of Indoor Daylight and Thermal Climate Conditions and use of Fan-Assisted Natural Ventilation in a Public Library.” J. Green Build., 1(4), 3–10. Parpairi, K., N. V. Baker, K. A. Steemers, and R. Compagnon. (2002). “The Luminance Differences index: a new indicator of user preferences in daylit spaces.” International Journal of Lighting Research and Technology, 34(1), 53–66. Yin, R. K. (2009). “Case Study Research—Design and Methods” Fourth Edition, SAGA Publications Inc. United States of America. Ward, G. (2011). Photosphere, (Computer program) Available at: www.anyhere.com. Wang, N., and M. Boubekri. (2011). “Design recommendations based on cognitive, mood and preference assessments in a sunlit workspace.” Lighting Research and Technology, 43(1), 55–72.

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Summary

Integrated Energy Design of the Building Envelope Summary of PhD thesis by Martin Vraa Nielsen The research project analyses how the implementation of scientific knowledge at an early stage of design quantifies the facade’s effect on the energyefficiency and indoor air quality of a building – with a view to facilitate a more qualified design development. The project examines the technical aspects and requirements impacting the facade design as well as the actual design process. The project applies the Integrated Energy Design method and evaluates its suitability in relation to facade design. Thus, the project actively looks into the design process in order to test the implementation of energy and comfort to achieve a more holistic building performance. The PhD project illustrates that there is a great potential in incorporating passive building properties in the geometric optimisation of the design. It demonstrates how the integration of technical know-how not only qualifies the geometry at an early design stage but also forms the basis of the actual facade design. By incorporating parameters such as overall facade geometry and orientation, functional layout, room height and depth, windows etc., you achieve a more holistic optimisation of the building performance.

the same time maintaining a very good indoor air quality and a high architectural quality. One of the main conclusions of the research project is that involvement of the engineer in the early concept stage creates common ground for collaboration. This allows for both the aesthetic and the energy-related potential to be fully exploited and thus adds value to the design concept. Genuine works of architecture represent a holistic approach to design, which should be adopted by all professional disciplines involved in the design development. The research project illustrates the importance of a successful interdisciplinary collaboration between engineers and architects. As opposed to some understandings, the performance of a building design is not first determined by the architect’s first sketch but is to a great extent already determined by the context and project brief. This means that both engineers and architects bear a heavy responsibility in the first, critical design stages.

Through a number of projects, this approach has contributed to the development of building designs which offer an energy consumption that is at least 25 % lower than minimum requirements, while at DESIGN WITH KNOWLEDGE |

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Solar Energy 85 (2011) 757–768 www.elsevier.com/locate/solener

Quantifying the potential of automated dynamic solar shading in office buildings through integrated simulations of energy and daylight Martin Vraa Nielsen ⇑, Svend Svendsen, Lotte Bjerregaard Jensen Department of Civil Engineering, Technical University of Denmark, Brovej, Building 118, DK-2800 Kgs. Lyngby, Denmark Received 14 September 2010; received in revised form 12 January 2011; accepted 20 January 2011 Available online 15 February 2011 Communicated by: Associate Editor J.-L. Scartezzini

Abstract The facade design is and should be considered a central issue in the design of energy-efficient buildings. That is why dynamic facade components are increasingly used to adapt to both internal and external impacts, and to cope with a reduction in energy consumption and an increase in occupant comfort. To gain a complete picture of any facade’s performance and subsequently carry out a reasonable benchmarking of various facade alternatives, the total energy consumption and indoor environment need to be considered simultaneously. We quantified the potential of dynamic solar shading facade components by using integrated simulations that took energy demand, the indoor air quality, the amount of daylight available, and visual comfort into consideration. Three types of facades were investigated (without solar shading, with fixed solar shading, and with dynamic solar shading), and we simulated them with various window heights and orientations. Their performance was evaluated on the basis of the building’s total energy demand, its energy demand for heating, cooling and lighting, and also its daylight factors. Simulation results comparing the three facade alternatives show potential for significant energy reduction, but greater differences and conflicting tendencies were revealed when the energy needed for heating, cooling and artificial lighting were considered separately. Moreover, the use of dynamic solar shading dramatically improved the amount of daylight available compared to fixed solar shading, which emphasises the need for dynamic and integrated simulations early in the design process to facilitate informed design decisions about the facade.  2011 Elsevier Ltd. All rights reserved. Keywords: Dynamic solar shading; Integrated simulation; Energy demand; Indoor environment; Office buildings

1. Introduction The ever-increasing focus on the environment and climate transformation as a consequence of the emission of greenhouse gasses means that the building industry is facing a new reality (IPCC, 2008; Brundtland, 1987). Energy consumption doubled in the period 1971–2007, and the operation of buildings accounts for 40% of the overall energy consumption (International Energy Agency, 2009). The Energy Performance of Buildings Directive (EPBD,

⇑ Corresponding author. Tel.: +45 4525 1902; fax: +45 4593 1755.

E-mail address: mavni@byg.dtu.dk (M.V. Nielsen).

0038-092X/$ - see front matter  2011 Elsevier Ltd. All rights reserved. doi:10.1016/j.solener.2011.01.010

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2002) has become an important part of the new reality, and with the recent political acceptance of the new version that prescribes that all new buildings must be “nearly zeroenergy buildings” by 2020 (EPBD, 2010), energy efficiency at every level within the built environment has simply become a prerequisite. The overall reason for constructing buildings is to shield occupants from the outdoor environment and obtain a certain level of indoor comfort. Consequently, to a great extent, it is the level of occupant comfort that determines how much energy is used to operate the building. This puts the facade, as the actual separator between the indoor and outdoor climate, at the centre of the “energy reduction issue”. Choosing the optimal facade, however, is a complex

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discipline with many, often contradictory, parameters of considerable interdependence (Ochoa and Capeluto, 2009). The introduction of dynamic fenestration creates the possibility of obtaining a more beneficial utilisation of the available resources, such as insolation and daylight, with respect to both energy demand requirements and occupant comfort (Lee et al., 1998). There has been previous research into dynamic fenestration technologies to determine their significance in relation to energy consumption and occupant comfort. Results show the potential of dynamic fenestration components, ranging from a decrease in cooling and lighting demand (Athienitis and Tzempelikos, 2002; Tzempelikos and Athienitis, 2007), reduced overall energy demand (Lollini et al., 2010), and improved daylight utilisation (Koo et al., 2010). All this provides insight into how a certain degree of responsiveness in the facade can have a beneficial effect. This article demonstrates that the selection of a facade design can only be justified by benchmarking various design alternatives early in the design process when decisions about the facade are made (Lo¨hnert et al., 2003). When making this comparison, it is important to simulate the performance of the facades as a result of the interaction with the building sub-systems (Lee et al., 2004; Franzetti et al., 2004). The potential energy reductions and increases in occupant comfort from the ability of dynamic facades to adapt to the considerable seasonal changes can only be achieved through an integrated process (Lee et al., 1998). For example, improving the interior daylight conditions can reduce the energy consumption for artificial lighting, but also increase the heat gain, and therefore affect the energy demand for heating, ventilation and/or cooling

(Johnson et al., 1984; Tzempelikos and Athienitis, 2007; Tzempelikos et al., 2007). The main objective of this article is to demonstrate the potential of dynamic solar shading with regard to both energy demand and the quality of the indoor environment through a series of integrated simulations. Our aim is to clarify how a number of interdependent parameters define and affect the performance of the facade. The focus is on investigating the performance of dynamic solar shading compared to fixed solar shading or no solar shading. We use integrated simulations to illustrate the importance of providing data that facilitates early design decisions with regard to the facade (Wilde and Voorden, 2004; Strachan, 2008; Petersen and Svendsen, 2010). 2. Striking a balance Obtaining the desired equilibrium between energy demand and occupant comfort can only be achieved at room level. Only on this scale is it possible to evaluate both behaviour and requirements with regard to the thermal and the visual indoor environment defined by the occupant. The balance that results in the desired level of comfort is often highly sensitive and is represented by many environmental factors (Fig. 1). Even minor alterations in either internal or external loads can have a relatively large impact on the energy demand for heating, cooling, ventilation or artificial lighting. Each of the facade components has a filtering effect on the external impacts, and the indoor environment can only be evaluated by considering the building envelope as a whole (Clarke et al., 1998). So the facade can be

Fig. 1. Typical room with environmental components.

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constructed with a number of static and dynamic components that, in combination, are capable of obtaining a better control of the outdoor climate compared with more traditional facades (Lee et al., 2002). For example: regulating the amount of solar heat gain and daylight can be obtained by installing dynamic solar shading; natural ventilation can be obtained through windows or openings (Fig. 2). Evaluating facades with dynamic properties requires us to perform equally dynamic simulations to determine the level of indoor environment and the energy demand for heating, cooling and artificial lighting. The simulations have to include weather data for the given location and generate results for both the thermal, visual and atmospheric indoor environment – especially when considering translucent components (Selkowitz, 1998). Only then can the components be controlled in accordance with both outdoor and indoor climate, and the potential reduction in energy demand as a consequence of the increased adjustability and the utilisation of the higher luminous efficiency of daylight can be determined (Strachan, 2008). So there is considerable interdependence between the composition of the facades, daylight availability, the need for heating, cooling and artificial lighting, the layout of workplaces, and the wishes of each individual occupant. We chose the fenestration system as a good representative for the often contradictory wishes for facades. Solar shading represents the first opportunity to control daylight and solar heat gain, which is often a key issue in obtaining workstations with sufficient amounts of daylight and avoiding overheating problems. This analysis focuses on early design decisions and therefore concentrates on the

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performance of dynamic solar shading in comparison with fixed solar shading and no solar shading. 3. Method 3.1. Simulation process Analyses were carried out using iDbuild (Petersen and Svendsen, 2010), a tool developed at the Technical University of Denmark, that performs hourly-based calculations of the total energy demand taking into account the energy needed for heating, ventilation, cooling, domestic hot water and artificial lighting. In principle, the program is made up of two parts: a thermal simulation handled by BuildingCalc (Nielsen, 2005), and a daylight simulation handled by LightCalc (Hviid et al., 2008). The integrated simulation is performed by feeding hourly daylight levels into the thermal simulation program. LightCalc essentially pre-calculates the daylight levels at given evaluation points without shading to provide initial values for the artificial lighting loads, the internal heat gain and subsequently the indoor air temperature. 3.1.1. Thermal simulation For each hourly time step, the thermal simulation evaluates the indoor air temperature based on the solar heat gain received through the windows, and the heat exchange with internal surfaces and with the external environment. Based on the indoor air temperature, the defined heating or cooling systems are controlled to achieve given set-point temperatures. If the indoor air temperature is below the heating set point, the heating system will be activated and

Fig. 2. Illustration of the components of the building envelope and the parameters of the external environment they can dynamically filter. Natural ventilation can be enabled through an opening above the window and controlled by a louver, while insolation can be controlled by solar shading.

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if the indoor air temperature is above the cooling set point, the defined systems will be activated in the following order: 1. 2. 3. 4.

Shading Venting (natural ventilation through windows) Increased mechanical ventilation Mechanical cooling

When one of these systems is activated, the thermal indoor environment is re-simulated for the given time step to include its effect and to determine the resulting indoor air temperature. The shading system can be controlled in accordance with the indoor air temperature, the risk of glare, or both. If either of the two conditions is exceeded, the solar shading will be fully lowered and, in the case of adjustable blinds, adjusted to a cut-off angle at which direct sun is just blocked. The risk of glare is evaluated in accordance with a daylight glare probability index proposed by Wienold and Christoffersen, 2006. If controlled according to both indoor air temperature and the risk of glare, the shading system will activate if either of the two conditions occur. If shading has been activated, the angle-dependent light transmittance determined by the WIS program (WinDat, 2006) is used to calculate the daylight level at the user-defined points (see Section 3.1.2 below). The artificial lighting levels required to achieve the given set points and the resulting heat gains from the lighting are determined. Finally, the solar heat gain is calculated by using an angle-dependent total solar energy transmittance for the fenestration system (including shading system) determined by the WIS program. The solar heat gain coefficient for the fenestration system is used for both the direct and the diffuse radiation. Venting is natural ventilation through the windows and can be activated and increased up to a given maximum air

flow. Mechanical ventilation can be varied between a maximum and a minimum air flow. Mechanical cooling is the final measure and will be activated if the indoor air temperature exceeds the cooling temperature set point after shading has been activated and both venting and mechanical ventilation has been increased to the maximum given value. Both the heating and cooling demands are determined analytically in each time step with respect to the given set-point temperatures when all other active systems controlling the indoor temperature have been activated. 3.1.2. Daylight simulation The LightCalc algorithm calculates hourly daylight levels, controls the shading system, and determines its effect on daylight levels, making photo-responsive lighting control possible. The simulation of daylight levels as a result of both diffuse and direct components combines several approaches in determining the external and the internal light distribution. Externally, the diffuse light from scattering in the atmosphere and from the ground and surroundings is modelled using an upper and a lower (inverted) sky dome, as suggested by Robinson and Stone (2006). The upper sky dome uses the Perez all-weather model (Perez et al., 1993) to determine the anisotropic sky radiation, while the lower sky dome is uniform with a constant luminosity expressed by a mean ground reflectance. Both sky domes are divided into 145 patches using the discretisation scheme proposed by Tregenza (1987). The internal light distribution is based on the luminous-exitance method that, like the radiosity method, treats the subdivided internal surfaces receiving transmitted direct and diffuse light as acting like light sources. The algorithms and the methodology behind the implementation are described by Park and Athienitis (2003).

Fig. 3. Geometry of the two-person office with the window centred in relation to the room width and an offset of 0.1 m on each side. The window height was defined from a window parapet with a fixed height of 0.8 m.

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The coupling between the internal and external environment is divided into three components: diffuse-to-diffuse, direct-to-diffuse and direct-to-direct. Each light component has a respective angle-dependent light transmittance calculated through WIS. When direct light hits the solar shading and diffuses, the diffuse-to-direct component is used. Interreflection between blinds and between the solar shading system and glazing is ignored. 3.2. Simulation model The potential of the dynamic facades was investigated through a number of cases to achieve a valid and plausible estimate. Each simulation represented a 3  3  6 m (width  height  depth) office space for two people, with a specific facade type and system configuration (HVAC and artificial lighting system). The window width was kept constant at 2.8 m while the window height was varied. Fig. 3 represents the model without solar shading and a window height of 1.5 m. The room was simulated as a single unit in a larger office building located in Denmark, and only the facade was exposed to the outside climate. Ceiling, floor and internal walls were assumed to face the same thermal environment as the room investigated and their thermal capacity was included. The model was simulated in an environment without any obstructing elements. Additional heat loss through the roof, gable and floor was added so that the energy demand of the office could still be considered representative for all rooms with the same orientation. With respect to building services (systems) and their control, a distinction was made between ‘occupancy’ (8 am to 5 pm) and ‘non-occupancy’ (midnight to 8 am and 5 pm to midnight), and also seasonal between a ‘summer’ situation (weeks 1–18 and 38–53) and a ‘winter’ situation (weeks 19–37). The distinction between summer and winter was made in accordance with the typical heating season in Denmark (EBST, 2006) and coupled with the seasonal temperature set points defined in the European standard (CEN, 2007). The office was occupied by two people and their equipment Monday–Friday throughout the year. Table 1 contains input data on geometry, construction, system configuration, and internal loads for the simulation models. Heating, ventilation, cooling and artificial lighting were only active during occupancy, while infiltration was constant the entire year. Natural ventilation through open windows, indicated as venting, was defined as the maximum air flow rates possible for single-sided natural ventilation during the summer season derived from the Danish standard (EBST, 2006). Set points for heating/cooling and air flow rates for mechanical ventilation corresponded with requirements for Class II in the European standard (CEN, 2007), and the power of the heating and cooling systems was assumed infinite. Both heating and cooling systems were simulated as active during occupancy the entire year, so that

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Table 1 Input values defining the simulation model with respect to geometry, system set-up and efficiency. Geometry Room – width  height  depth Window width and height Width of window frame construction

336m 2.8  1.5 m 0.1 m

Constructions Heat transfer coefficient of opaque facade construction (U-value) Heat transfer coefficient of glazing (U-value) Light transmittance of glazing (LT) Total solar energy transmittance of glazing Heat transfer coefficient of frame construction (U-value) Linear heat transmittance of window frame (Psi-value) Systems and internal loads

0.15 W/m2 K 0.7 W/m2 K 0.53 0.40 1.5 W/m2 K 0.1 W/m K

Occupancy (8 am to 5 pm)

Nonoccupancy

20/24 C 23/26 C 0.1 h1 1.48 l/sm2 0.8

– – 0.1 h1 0.0 l/sm2 –

1.5 kJ/m3 1.8 l/sm2 2.5 10 W/m2

– 0.6 l/sm2 – 1 W/m2

General lighting Illuminance set point max. power min. power (stand-by)

200 lux 6 W/m2 0.5 W/m2

– 0 W/m2 0 W/m2

Task lighting Illuminance set point max. power min. power

500 lux 1.2 W/m2 0 W/m2

– 0 W/m2 0 W/m2

Set-point temperatures – heating/cooling Summer Winter Infiltration Mechanical ventilationa Heat exchanger efficiency of mechanical ventilationb Specific fan power, SFP Venting rate (maximum)c Mechanical cooling, efficiency (COP) Internal loads from persons and equipment

a Equivalent to indoor air quality Class II in the European standard EN 15251:2007 (CEN, 2007). b Bypass of heat exchanger possible. c Defined as ventilation through open windows. Only active outside the heating season and corresponds to maximum values for single-sided natural ventilation in Danish energy calculations (EBST, 2006).

the system set-up would result in temperatures and air quality that always corresponded to Class II requirements. The artificial lighting, in terms of both general and task, was controlled in accordance with daylight availability. It was assumed that work stations would be placed as close to the facade as possible. To represent a relatively conservative indication of the available daylight the evaluation point for the daylight level was placed four metres from the facade, 0.85 m above the floor and centred in relation to the room width. The assumption was made for this particular simulation model with two occupants so as to explore the full effect of photo-responsive lighting control in combination with dynamic solar shading. It would need to be re-evaluated if more occupants were added, if the layout of work stations were different, or if the overall room

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geometry changed. General lighting was controlled by a continuous, linear dimming profile that supplements the amount of daylight available with artificial lighting. The dimming control of the general lighting interpolated linearly between the maximum and minimum power in order to meet the specified set point (200 lux). Task lighting was either on at maximum power, if the daylight level was below the set point (500 lux), or off, if it was above the set point. It should be noted that power for both general and task lighting in Table 1 indicates a power density (W/m2) applicable for the entire floor area. Thus, the value for the task lighting of 1.2 W/m2 corresponds to one 11 W low-energy light bulb per occupant supplying 500 lux at the work station, whereas the general lighting at maximum power of 6 W/m2 supplies 200 lux. 3.3. Parameter variations A series of parameter variations were carried out in order to clarify how various solar shading types affected the indoor environment and the energy consumption. The objective was a continuous comparison of the facade alternatives to obtain a reasonable picture of the performance of the dynamic solar shading, i.e. its ability to control solar gains and thus its applicability in various situations. Three different solar shading types (no solar shading, with dynamic solar shading, and with fixed solar shading) were investigated through all these parameter variations (Fig. 4). The fixed and the dynamic solar shading were modelled as a horizontal, grey Venetian blind with slat thickness, width and distance equal to 0.22 mm, 50 mm and 42.5 mm respectively and a reflectance of 0.54. The fixed solar shading was modelled as being fixed in the horizontal position and not retractable, and thus active during both occupancy and non-occupancy. The dynamic solar shading was modelled as pivoting and fully retractable, and during occupancy controlled according to the indoor air tempera-

ture and risk of glare. If either of the two conditions occurred, the blinds were fully lowered and adjusted to the slat angle at which direct sun was just blocked (the cut-off angle), thus maximising the amount of daylight entering the room while optimising the indoor environment with respect to glare and overheating (Hviid et al., 2008). Outside occupancy, the dynamic solar shading was only controlled in accordance with indoor air temperature. 3.3.1. Design variables Integrated daylight and thermal simulations of the three solar shading types were performed for two design variables through a number of parameter variations as seen in Table 2. The window height in relation to facade transparency was defined from the work plane (0.8 m above the floor) and vertical upward. The width of the window was kept constant at 2.8 m, so by increasing the window height the area of the opaque facade was reduced and both the total heat transfer coefficient (U-value) of the facade and the amount of solar radiation entering the room increased. All models were simulated with the glazing and frame properties indicated in Table 1. 3.4. Evaluation criteria Based on the simulation results, each design variable and its effect in relation to energy performance and indoor environment were evaluated. The evaluations were performed on the basis of the following parameters:    

Total energy demand of the model. Energy demand for heating. Energy demand for cooling. Energy demand for artificial lighting.

Table 2 For all three solar shading types, integrated simulations were performed for each of the four major orientations and three different window heights. What

Why

How

Simulated models

Orientation

Influences the incident amount of solar radiation the facade receives Defines the amount of heat gain and daylight that enters the room

Orientation of window

North, south, east and west 1.0 m, 1.5 m and 2.0 m

Facade transparency

Window height

Table 3 List of primary energy factors as stated in the Danish building regulations (EBST, 2006) and how they are used in the simulations.

Fig. 4. Illustrations of the three different solar shading types: (a) Reference model without solar shading, (b) Model with fixed solar shading, and (c) Model with dynamic and fully retractable solar shading.

Energy source

Factor

Simulation model

Gas, oil and district heating Electricity

1

Space heating and domestic hot water

2.5

Cooling, fans for mechanical ventilation and artificial lighting

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 Daylight represented by the daylight factor and usable area for workstations. To assess the total energy demand as required in the energy directive from the European parliament (EPBD, 2002), a domestic hot-water consumption of 100 l/m2 corresponding to the Danish standard for offices was added. Energy performance was evaluated using primary energy factors as indicated in Table 3 corresponding to the Danish building regulations (EBST, 2006). The thermal indoor environment and the air quality were both evaluated in accordance with the European standard EN 15251:2007 (CEN, 2007). The heating and cooling set points and the air flow for the mechanical ventilation corresponded to the requirements for indoor environment Class II. The energy demand for ventilation was equal for all models since the specific fan power and the airflow was constant, also corresponding to indoor environment Class II. Because the available heating and cooling power was assumed to be infinite, the requirements for indoor environment Class II with respect to thermal environment and air quality were always fulfilled for all models during occupancy. It should be noted, however, that while the heating and cooling systems were both simulated as active all year during occupancy and therefore resulted in an increased consumption, they do render possible a simple and clear comparison of the performance of the different facades. Since the requirements for the quality of the indoor environment were fulfilled, the energy used for heating, cooling and artificial lighting gives a clear indication of the facade’s ability to control both internal and external impacts to maintain a good indoor environment. The addition of natural ventilation (venting) outside the heating season was made to clarify whether or not some facade designs for certain orientations performed well enough to render cooling obsolete. E.g. problems with overheating outside the heating season would either not exist or be small enough to be handled by an increased air flow obtained through natural ventilation. The amount of daylight available was evaluated based upon the daylight factor in the working plane (0.85 m above the floor) and simulated using the CIE standard

overcast sky, which delivers 10,000 lux on an outside unobstructed horizontal surface. The daylight factor indicates the ratio between the daylight on an internal surface and the daylight on an unobstructed external surface and will therefore not differ in accordance with orientation, day or hour. Whether or not workstations could be established was defined by a daylight factor threshold of 2%, which under a CIE standard overcast sky corresponds to an illuminance level of 200 lux. The threshold connects to the general lighting level and thus corresponds to the illuminance set point for the general lighting as defined in Table 1. 4. Results Comparative data with respect to both energy demand and daylight factors are presented below for the three solar shading types: no solar shading, fixed solar shading, and dynamic solar shading. 4.1. Energy demand The data are arranged according to window height and orientation. All models were simulated for an entire year and the results correspond to the annual energy demand per square metre (kWh/m2 per year). As seen in Fig. 5, all the simulated models resulted in an energy demand below 70 kWh/m2 per year, and approximately 22% of the models (7 out of 36) show an energy demand below 50 kWh/m2 per year. The best-performing facade faced south, with a window height of 1.5 m and dynamic solar shading, whereas the worst-performing facade faced north, with a window height of 1.0 m and fixed solar shading. The two facades, best and worst, were simulated to have a total energy demand of 46 kWh/m2 per year and 66 kWh/m2 per year, respectively. Generally, the facade with dynamic solar shading had the best performance with respect to total energy demand. In most cases, facades with fixed solar shading had the worst performance, except for facades facing south, east and west with a window height of 2.0 m, where the facades with no solar shading had the worst performance. The vari-

Fig. 5. Annual energy demand for simulated models depending on orientation, window height and solar shading types.

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ations in energy demand between the three different solar shading types were generally of the same magnitude in all cases. Because air flow rates were determined in accordance with indoor air quality (number of occupants and floor area) as defined in the European standard (CEN, 2007), energy demands for ventilation and for domestic hot water were constant for all models corresponding to 13 kWh/m2 per year and 5 kWh/m2 per year, respectively. Subsequently the differences in total annual energy demand were caused by differences in the energy demand for heating, cooling and artificial lighting. The distribution of energy demand for heating, cooling and artificial lighting, as seen in Figs. 6–9, shows that the north, east and west-facing facades have an increased heating demand when the window height (i.e. the facade transparency/window area) is increased due to the greater heat transmission through the glazed component than through the opaque parts. South-facing facades have a varying tendency depending on the solar shading types. For all models, the energy demand for artificial lighting decreases as the facade transparency and the insolation increases. The energy demand for cooling generally increases as the window height increases, but the increase is proportionally greater in the cases without solar shading for the orientations south, east and west (Figs. 6–9).

4.2. North Models with facades facing north showed a reduction in total annual energy demand between the worst (at 66 kWh/ m2 per year) and the best-performing facade (at 58 kWh/ m2 per year) amounting to approximately 12% (Fig. 6). The north-facing facades with no solar shading or fixed solar shading had the best performance at a window height of 1.5 m, whereas the facades with dynamic solar shading had the best performance at a window height of 2.0 m. All the performance indicators showed similar tendencies and magnitudes for all types of solar shading. When the window height was increased, the heating and cooling demand increased and the energy demand for artificial lighting decreased. 4.3. South Models with facades facing south showed a reduction in total annual energy demand between the worst (55 kWh/ 2 m per year) and best-performing facade (46 kWh/m2 per year) amounting to approximately 16% (Fig. 7). The facade with no solar shading performed equally well with window heights of 1.0 m and 1.5 m. The facade with fixed solar shading had the best performance at a window height of

Fig. 6. Distribution of annual energy demand for heating, cooling and artificial lighting for simulation models with facades facing north.

Fig. 7. Distribution of annual energy demand for heating, cooling and artificial lighting for simulation models with facades facing south.

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Fig. 8. Distribution of annual energy demand for heating, cooling and artificial lighting for simulation models with facades facing east.

Fig. 9. Distribution of annual energy demand for heating, cooling and artificial lighting for simulation models with facades facing west.

2.0 m, whereas the facade with dynamic solar shading had the best performance at a window height of 1.5 m. The tendencies of the performance indicators were similar for facades with fixed and with no solar shading, but the magnitudes differed. When the window height was increased, the heating and lighting demand decreased while the cooling demand increased. Facades with dynamic solar shading displayed an increase in heating and cooling demand, but a decrease in energy demand for artificial lighting. The facades with no solar shading displayed considerable interdependence between all the performance indicators: increasing the window height resulted in an increased cooling demand that exceeded the combined decrease in energy demand for heating and artificial lighting. The facades with fixed or dynamic solar shading showed similar magnitudes of variation between the performance indicators. 4.4. East and west Models with facades facing east showed a reduction in total annual energy demand between the worst (63 kWh/ 2 m per year) and best-performing facade (55 kWh/m2 per year) amounting to approximately 13% (Fig. 8). The eastfacing facade with no shading performed equally well at

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window heights of 1.0 m and 1.5 m. The east-facing facade with fixed solar shading had the best performance at a window height of 1.5 m, whereas the facade with dynamic solar shading performed equally well at window heights of 1.5 m and 2.0 m. Models with facades facing west showed a reduction in total annual energy demand between the worst (62 kWh/ 2 m per year) and best-performing facade (54 kWh/m2 per year) amounting to approximately 13% (Fig. 9). The west-facing facade with no shading performed equally well at window heights of 1.0 m and 1.5 m. The west-facing facade with fixed solar shading performed equally well at window heights of 1.5 m and 2.0 m. The west-facing facade with dynamic solar shading had the best performance at a window height of 1.5 m. For east and west-facing facades, all the performance indicators showed similar tendencies for all window heights and types of solar shading. When the window height was increased, the energy demand for heating and cooling increased and the energy demand for artificial lighting decreased. All east and west-facing facades showed a proportionally greater difference in the energy demand for artificial lighting when the window height increased from 1.0 m to 1.5 m compared to an increase in window height from 1.5 m to 2.0 m. For east and west-facing facades with no

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solar shading, the energy demand for cooling was greater than for facades with fixed or dynamic solar shading. 4.5. Daylight The amount of daylight for the three different types of solar shading at window heights of 1.0 m, 1.5 m and 2.0 m are presented in the form of daylight factors and depicted in Fig. 10, with the threshold of a 2% daylight factor indicated. Because of the uniform overcast-sky conditions, the dynamic solar shading was not activated and daylight factors for models with no solar shading and models with dynamic solar shading were equal. In general, the daylight factor decreases as the distance from the facade increases and the window height decreases. The results group the performances of the facades with respect to daylight factors via varying dependence on the distance from the window. The facades with no solar shading or with dynamic solar shading displayed a greater dependence on the distance from the window compared to the facades with fixed solar shading, and they displayed a more dramatic decrease in the daylight factor as the distance from the facade increased than did facades with fixed solar shading. The difference between the two groups was greatest close to the facade and decreased as the distance from the facade increased, so that daylight factors tended to converge at the back of the room, but still with considerable differences. However, where the window height was the same, facades with no solar shading and facades with dynamic solar shading always performed better with respect to daylight than facades with fixed solar shading. With regard to the amount of daylight, only facades with a window height of 2 m with no solar shading or with dynamic solar shading provided a daylight factor of a minimum of 2% in the entire working zone. Under CIE overcast-sky conditions, only these facades provided an illuminance of minimum 200 lux for the area extending 4 metres from the facade and thereby enough daylight for

the general lighting to be dimmed to the minimum effect indicated in Table 1. Reducing the window height to 1.0 m or 1.5 m reduced the distance from the facade where a minimum of 2% daylight factor could be maintained to 2.25 or 3.5 m, respectively. For facades with fixed solar shading, window heights of 1.0 m, 1.5 m and 2.0 m meant that the distance from the facade where a minimum of 2% daylight factor could be maintained was approximately 1.0 m, 2.0 m and 3.0 m, respectively. 5. Discussion The results for the simulated parameter variations illustrate that even in the relatively cold north-European climate, where heating often dominates the total energy consumption, energy demand for cooling and artificial lighting are also important – especially in low-energy buildings. General for all orientations, of course, is that increased facade transparencies allow more insolation into the room. A general tendency that is observed is a reverse proportionality between cooling and artificial lighting. However, the energy demand for heating and cooling depends not only on increased insolation, which varies greatly depending on the orientation, but also on the change in the thermal performance of the facade that occurs when glazing replaces an opaque facade. Furthermore, our simulations of the daylight factors showed a much greater difference in performance between facades with no solar shading or with dynamic solar shading and facades with fixed solar shading. The results for the cases examined show that in most cases dynamic solar shading constitutes the best design alternative, but also that the difference in total energy demand between the best and the second best are minor and can be non-existent. Thus, when all results are considered, the difference in total energy demand between the worst and the best-performing facade for a given orientation does not exceed 16%. With respect to energy, facades

Fig. 10. Daylight factors in the working plane (0.85 m above the floor) along the centreline in the room in relation to the distance from the window depicted by solar shading type and window height, using the CIE overcast sky. Daylight factors for facades with no solar shading and facades with dynamic solar shading are equal because the dynamic solar shading would not be activated under overcast-sky conditions. The threshold of a 2% daylight factor corresponding to 200 lux when the illuminance on an outside unobstructed surface is 10,000 lux has been indicated.

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with fixed or no solar shading are a relevant alternative for all facades facing north and for facades with window heights of 1.0 m or 1.5 m facing south, east and west. But when it comes to daylight factors, dynamic solar shading shows a dramatic improvement in performance over fixed solar shading. The increased daylight factor results in an expansion of the well-lit area by 70–150%. The increased amount of daylight available provided by a dynamic solar shading more adaptable to the climate, therefore allows a greater and more flexible utilisation of the space, so that more work stations can be established. The facade design, the geometry of the room and its function should therefore be considered simultaneously. It should be noted that the daylight factor, although a simple indication of a worstcase scenario, is still a measure used to document the amount of daylight. Furthermore, the energy demand for the photo-responsive artificial lighting with a continuous dimming profile controlled in accordance with weather data will ultimately reflect the amount of daylight available similar to the daylight autonomy. Thereby the two measures together satisfactorily indicate the facade’s performance with respect to daylight. Thus the results prove the importance of integrated simulations to quantify the potential of dynamic fenestration systems due to the great interdependence of the various parameters. Furthermore, this quantification needs to be performed in the early stages of the design process, where essential design decisions defining the framework and preconditions for the building’s performance are made – not only to obtain a more complete performance assessment, but also to better tailor the facade design to the actual building, its layout and its function. Open plan offices with work stations far from the facade require high facade transparency and a dynamic solar shading to obtain sufficient amounts of daylight without having problems with overheating, whereas fixed solar shading could be considered for a one or two-person office where work stations can be established close to the facade. Dynamic solar shading with its ability to reduce energy consumption and improve occupant comfort may therefore not always be the optimal choice when economics (acquisition and maintenance) or subjective factors such as aesthetics are included. Each simulation was only performed on a single, but representative room in the perimeter zone of a building, and the interaction with the rest of the building was considered as increased transmission heat loss through the roof, gable and floor. The actual performance of the entire building depends not only on the control strategy chosen for each room, but on the control strategy for the entire building. However, our focus was on depicting the performances of different facade designs and the importance of considering alternatives. iDbuild provides adequate information for the comparison and evaluation of various alternatives in respect to both indoor climate and energy consumption. It should be noted that the results represent a building placed in a totally unobstructed environment and therefore with a high degree of daylight available. In an urban envi-

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ronment, where a smaller amount of daylight is available, the potential disadvantage of permanently reducing the amount of daylight by implementing fixed solar shading and thereby increasing the energy demand for artificial lighting is not fully disclosed. Moreover, this article focuses on comparing facades with no solar shading with one specific type of dynamic and fixed solar shading. Therefore the results cannot be used for an evaluation of dynamic solar shading or dynamic fenestration systems in general. However, investigation of other dynamic facade components will form part of our future work. Furthermore, the highly glazed facades which seem to be a prevailing element in modern office buildings mean that dynamic solar shading is very relevant for the control of large amounts of insolation and minimise the risk of overheating, while still providing views of the outside. This relevance will only increase when the stricter demands for “nearly zero-energy buildings” are implemented in 2020 (EPBD, 2010). 6. Conclusion To quantify the potential of dynamic solar shading, we have presented simulation-based results from an investigation of three different solar shading types. Integrated thermal and daylight simulations were carried out to demonstrate comparable results of the performances of the facades with respect to energy consumption and indoor environment. The performances of the facades were evaluated in terms of total energy demand, the individual energy demands for heating, cooling and artificial lighting, and also the amount of daylight in terms of daylight factor. The quality of the indoor environment for all the models simulated complied with Class II defined in the European standard CEN 15251, 2007. For a typical office located in Denmark, the significance of orientation, window area and solar shading types was investigated to emphasise the importance of involving design alternatives in the early stages of design, when critical decisions on the design of the facade are made. The work presented demonstrates how an available open source program can perform integrated simulations, reveal a high degree of interdependence between parameters, and thus make it possible to quantify a facade’s performance in a given context and achieve harmony between the layout of the building and its functions. References Athienitis, A.K., Tzempelikos, A., 2002. A methodology for simulation of daylight room illuminance distribution and light dimming for a room with a controlled shading device. Solar Energy 72 (4), 271–281. Brundtland, G.H., 1987. World Commission on Environment and Development. In: Our Common Future. Oxford University Press, Oxford. CEN, 2007. EN15251:2007 – Indoor environmental input parameters for design and assessment of energy performance of buildings – addressing indoor air quality, thermal environment, lighting and acoustics. Clarke, J.A., Janak, M., Ruyssevelt, P., 1998. Assessing the overall performance of advanced glazing systems. Solar Energy 63 (4), 231–241.

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EBST, 2006. Bygningsreglement for erhvervs- og etagebyggeri. In: National Agency for Enterprise and Construction. Copenhagen, Denmark. EPBD, 2002. Energy Performance Building Directive – Directive 2002/91/ EC of the European Parliament and of the Council of 16 December 2002 on the Energy Performance of Buildings. EPBD, 2010. Directive 2010/. . ./EU of the European Parliament and of the Council of on the Energy Performance of Buildings (recast). <http://register.consilium.europa.eu/pdf/en/10/st05/st05386-ad01.en 10.pdf>. Franzetti, C., Fraisse, G., Achard, G., 2004. Influence of the coupling between daylight and artificial lighting on thermal loads in office buildings. Energy and Buildings 36 (2), 117–126. Hviid, C.A., Nielsen, T.R., Svendsen, S., 2008. Simple tool to evaluate the impact of daylight on building energy consumption. Solar Energy 82 (9), 787–798. IEA, 2009. Key World Energy Statistics 2009. International Energy Agency, Paris. IPCC, 2008: Climate Change 2007: Synthesis Report. Contribution of Working Groups I, II and III to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change [Core Writing Team, Pachauri, R.K., Reisinger, A. (Eds.)]. IPCC, pp. 30. Johnson, R., Sullivan, R., Selkowitz, S., Nozaki, S., Conner, C., Arasteh, D., 1984. Glazing energy performance and design optimization with daylighting. Energy and Buildings 6 (4), 305–317. Koo, S.Y., Yeo, M.S., Kim, K.W., 2010. Automated blind control to maximize the benefits of daylight in buildings. Building and Environment 45 (6), 1508–1520. Lee, E.S., DiBartolomeo, D.L., Selkowitz, S.E., 1998. Thermal and daylighting performance of an automated venetian blind and lighting system in a full-scale private office. Energy and Buildings 29 (1), 47–63. Lee, E., Selkowitz, S.E., Bazjanac, V., Inkarojrit, V., Kohler, C., 2002. High-performance commercial building facades. Lawrence Berkeley National Laboratory: Lawrence Berkeley National Laboratory. LBNL Paper LBNL-50502. <http://www.escholarship.org/uc/item/ 7d30b3rd> (accessed 14.09.10). Lee, E.S., DiBartolomeo, D.L., Rubinstein, F.M., Selkowitz, S.E., 2004. Low-cost networking for dynamic window systems. Energy and Buildings 36 (6), 503–513. Lollini, R., Danza, L., Meroni, I., 2010. Energy efficiency of a dynamic glazing system. Solar Energy 84 (4), 526–537.

Lo¨hnert, G., Dalkowski, A., Sutter, W., 2003. Integrated Design Process: A Guideline for Sustainable and Solar-Optimised Building Design. International Energy Agency (IEA) Task 23 Optimization of Solar Energy Use in Large Buildings, subtask B. Austria. Nielsen, T.R., 2005. Simple tool to evaluate energy demand and indoor environment in the early stages of building design. Solar Energy 78 (1), 73–83. Ochoa, C.E., Capeluto, I.G., 2009. Advice tool for early design stages of intelligent facades based on energy and visual comfort approach. Energy and Buildings 41 (5), 480–488. Park, K.-W., Athienitis, A.K., 2003. Workplane illuminance prediction method for daylighting control systems. Solar Energy 75 (4), 277–284. Perez, R., Seals, R., Michalsky, J., 1993. All-weather model for sky luminance distribution – preliminary configuration and validation. Solar Energy 50 (3), 235–245. Petersen, S., Svendsen, S., 2010. Method and simulation program informed decisions in the early stages of building design. Energy Buildings 42 (7), 1113–1119. Robinson, D., Stone, A., 2006. Internal illumination prediction based on a simplified radiosity algorithm. Solar Energy 80 (3), 260–267. Selkowitz, S.E., 1998. The Elusive Challenge of Daylighted Buildings. Daylighting’98 Conference, Ottawa, Canada. Strachan, P.A., 2008. Simulation support for performance assessment of building components. Building and Environment 43 (2), 228–236. Tregenza, P.R., 1987. Subdivision of the sky hemisphere for luminance measurements. Lighting Research and Technology 19 (1), 13–14. Tzempelikos, A., Athienitis, A.K., 2007. The impact of shading design and control on building cooling and lighting demand. Solar Energy 81 (3), 369–382. Tzempelikos, A., Athienitis, A.K., Karava, P., 2007. Simulation of facade and envelope design options for a new institutional building. Solar Energy 81 (9), 1088–1103. Wienold, J., Christoffersen, J., 2006. Evaluation methods and development of a new glare prediction model for daylight environments with the use of CCD cameras. Energy and Buildings 38 (7), 743–757. Wilde, P.D., Voorden, M.V.D., 2004. Providing computational support for the selection of energy saving building components. Energy and Buildings 36 (8), 749–758. WinDat, 2006. Window Information System software (WIS), WinDat Thematic Network, TNO Bouw, Netherlands. <http:// www.windat.org>.

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Project overview This overview provides information on the location, gross floor area, year of design/construction, type of assignment, client and collaboration partners of the 15 projects presented in the cases of the book. The projects are arranged alphabetically according to name. Campus Roskilde p 95 Location  : Roskilde, Denmark Client : University College Sjælland Gross floor area : 20,000 m2 Construction period : 2010-2012 Type of assignment : 1st prize Team : Henning Larsen Architects, Cowi, Thing & Wainø and Enemærke & Pedersen

Carlsberg City District p 83 Location  : Copenhagen, Denmark Client  : Carlsberg Properties Gross floor area : 80,000 m2 Design period : 2011 Type of assignment  : Competition proposal, finalist Team :  Henning Larsen Architects, Dorte Mandrup Architects, Polyform Architects, Signal Architects, Wohlert Architects, Peter Andreas Sattrup

Energinet.dk Office Building p 67 Location  : Ballerup, Denmark Client  : Energinet.dk Gross floor area : 4,000 m2 Construction period : 2010-2011 Type of assignment  : 1st prize Team :  Henning Larsen Architects, Schul Landscape Architects, Dahl Enterprise and Hansen, Carlsen & Frølund

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King Abdullah Financial District pp 61, 122 Location : Riyadh, Saudi Arabia Client : Capital Market Authority and Public Pensions Agency Gross floor area : 1,600,000 m2 Design period : 2006-2010 Type of assignment  : 1st prize, international Team : Henning Larsen Architects, Buro Happold, Møller & Grønborg, DTZ and Geoffrey Barnett Associates

Klaksvík City Centre Location : Klaksvík, Faroe Islands Client  : Klaksvík Municipality Gross floor area : 150,000 m2 Design period : 2012 Type of assignment  : 1st prize, international Arkitekt : Henning Larsen Architects

p 39

Klostermarksskolen Location  : Roskilde, Denmark Client  : Roskilde Municipality Gross floor area : 1,000 m2 Construction period : 2011-2012 Type of assignment  : 1st prize Team : Henning Larsen Architects and Hundsbæk & Henriksen

p 51

Novo Nordisk Corporate Centre pp 23, 115 Location  : Bagsværd, Denmark Client  : Novo Nordisk Gross floor area : 50,200 m2 Construction period : 2011-2013 Type of assignment  : 1st prize Team : Henning Larsen Architects, SLA Landscape Architects and Alectia

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Nørrebro City District pp 36, 102, 120 Location : Copenhagen, Denmark Gross floor area : 150,000 m2 Status : Completed 2012 Team : Henning Larsen Architects, Algreen Architects and Peter Andreas Sattrup

Kolding Campus - University of Southern Denmark p 45 Location  : Kolding, Denmark Client :  The Danish Property Agency Gross floor area : 13,600 m2 Construction period : 2012-2013 Type of assignment  : 1st prize, international Team : Henning Larsen Architects, Orbicon and Kristine Jensen Landscape Architects

Siemens Headquarters p 73 Location  : Munich, Germany Client  : Siemens Gross floor area : 45,000 m2 Construction period : 2011-2015 Type of assignment  : 1st prize, international Team : Henning Larsen Architects, Topotek1, Werner Sobek, Transsolar, PMI, Müller BBM, AG Licht and CL MAP

Spiegel Headquarters p 110 Location  : Hamburg, Germany Client : Robert Vogel & Co and ABG & Co Gross floor area : 50,000 m2 Construction period : 2008-2011 Type of assignment  : 1st prize, invited Team : Henning Larsen Architects, Höhler + Partner, WES & Partner, Ingenieurbüro Dr. Binnewies, DS-Plan, Schlegel und Reußwig, Kardorff Ingenieure Lichtplanung and Ippolito Fleitz Group 188 | DESIGN WITH KNOWLEDGE

Thomas B. Thriges Gade pp 80, 115 Location  : Odense, Denmark Client  : Odense Municipality Gross floor area : 50,000 m2 Design period : 2011-2012 Type of assignment  : Competition proposal, finalist Team : Henning Larsen Architects, Polyform Architects, Drees og Sommer, WTM Engineers, Argus Engineering, Rambøll, Speirs + Major and Procasa

Umeå School of Architecture p 89 Location  : Umeå, Sweden Client  : Balticgruppen Gross floor area : 5,000 m2 Construction period : 2007-2011 Type of assignment  : Commission Team : Henning Larsen Architects, White Architects, Rambøll Swedem, TM-Konsult and LPS Konstruktörer

Viborg City Hall p 29 Location  : Viborg, Denmark Client  : Viborg Municipality Gross floor area : 19,400 m2 Construction period : 2009 – 2011 Type of assignment  : 1st prize, international Team : Henning Larsen Architects, Cowi and LIW Planning

Västra Dockan p 58 Location  : Malmø, Sweden Client : Malmö City & Dockan Exploatering Gross floor area : 80,000 m2 Design period : 2008-2009 Type of assignment  : Competition proposal Team : Henning Larsen Architects and LIW Planning

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Glossary ATES e.g. p 48 ATES is short for Aquifer Thermal Energy Storage. An ATES system is a ground water system with two units – one for cooling and one for heating.

Energy renovation e.g. pp 51, 138 Energy renovation has become a commonly applied strategy. Re-insulation is a typical example of energy renovation.

Building envelope e.g. p 53 The building envelope is where the building meets the outside space. The term not only covers the vertical surfaces but also the roof and ground decks.

Facade design e.g. pp 31, 75, 97 A substantial part of the energy-optimising and producing measures introduced have direct influence on the facade design.

Certification e.g. pp 73, 110, 111 Many different certification systems exist today. Denmark applies the German system DGNB.

Functional layout e.g. pp 65, 73, 83 Functional layout is another word for the organisation of the various functions in a building. The functions have different needs for indoor air quality

Climate conditions e.g. pp 40, 62, 122 In the northern hemisphere, the sun is gladly welcomed – while protection from the intense sun is preferred in desert countries such as Saudi Arabia. Comfort e.g. pp 45, 52, 58 Comfort is about the users’ experience of a building or an urban space. It is determined by a comfortable climate and an intelligent layout. Complete renovation e.g. p 138 Complete renovation projects are based on longer time perspectives than usual and incorporate for instance social or health-related aspects. Context e.g. pp 24, 30, 40 The context of a building is the buildings, the city, the landscape and the society that the building must relate to. Daylight e.g. pp 37, 47, 121 Daylight is the most important means of achieving a dynamic, experiential design. At the same time, it is a significant parameter in sustainable urban planning and building design. Density e.g. pp 62, 106 Density is a wide-spread concept in the development of sustainable cities. The denser a city is, the fewer resources are used. Dry cooling e.g. p 26 As opposed to traditional cooling towers, a dry cooling system dissipates excess heat by means of ventilators instead of liquid. 190 | DESIGN WITH KNOWLEDGE

Geometry e.g. pp 24, 84, 96 The geometry of a building or a city has a great impact on the energy consumption. The geometry regulates the amount of daylight in a building. Groundwater cooling and heating e.g. pp 32, 48 Groundwater cooling is used for space and process cooling. A groundwater cooling system provides cooling by exploiting the natural temperature of the groundwater. Green roof e.g. pp 25, 31 Green roofs delay the percolation of rainwater on site, convert CO2 into oxygen and cleans the air from particles. Heavy structures e.g. pp 47, 75, 97 Concrete has a special ability to transmit and store heat and cold. By exposing the building structures, this ability is exploited to control the indoor air quality. Holistic approach e.g. p 102 Taking a holistic design approach results in resource-conscious architecture in construction and in operation. Indoor air quality e.g. pp 47, 116, 123 The comfort of a building largely depends on the indoor air quality, which is regulated by healthy, nontoxic materials, acoustics, air exchange and temperatures.

Integrated (Energy) Design e.g. pp 67, 105 The method allows you to design cities and buildings that solely by means of design achieve the lowest possible energy consumption. Infrastructure e.g. pp 62, 81 Infrastructure that offers reduced focus on private car transport and increased focus on public transport, cyclists and pedestrians has a highly positive influence on the environment. Land use e.g. pp 59, 52 Land use is a central concept in the sustainable design of cities and buildings. City density and building compactness are important parameters. Lighting e.g. pp 54, 98 Installation of sustainable light fittings is an energy-optimising measure. Needs-based or daylightbased LED technology is a widely used means of ensuring a sustainable building. Local roots e.g. s. 40, 111 A project should be rooted in the local context, including the cultural, climatic and urban context. Materials e.g. pp 84, 111, 119 Sustainable materials have a large influence on the energy consumption and comfort of a building. All buildings should have an overall material strategy. Microclimate e.g. pp 40, 58 Microclimate refers to the local climate around the building. It is affected by very small changes of for instance the adjacent buildings.

Reflectance e.g. pp 119, 120 Reflectance addresses the ability of the surface to reflect light. This has a significant influence on the amount of daylight in and around the building and depends on the material selection. Sustainability e.g. pp 29, 73, 91 Sustainability is a complex concept that must be limited when used in practice. Solar design e.g. pp 37, 106 Solar design is a means of renovating the individual buildings and dwellings in the city with a view to optimise aesthetics, daylight and comfort. Solar cell system e.g. pp 32, 48, 76 A solar cell system generates energy from the rays of the sun. It can be integrated into the building in many ways, for instance on the roof or in the facade. Transparency e.g. pp 111, 123 The transparency of a building impacts its energy consumption and visual contact to the surroundings. Glass can be more or less transparent. U-value e.g. p 53 U-value is most often used to express the insulation performance of windows and building envelopes. Green buildings aim for a low U-value. Urban space design e.g. pp 58, 80, 106 Urban space design deals with the function, position, orientation, flow etc. of the individual spaces â&#x20AC;&#x201C; from the first sketches to completed project.

Position and orientation e.g. pp 24, 46, 96 The orientation and position of the building are decisive in terms of making optimal use of its passive properties.

Ventilation, natural e.g. pp 54, 97 Natural ventilation adds fresh air to and dissipates used air from a building by means of different temperatures in the various building spaces and by making use of wind through windows and doors.

Preservation e.g. pp 40, 74 Demolition causes significant economic and environmental impacts. Partly preservation can thus form part of a sustainable strategy.

Ventilation, mechanical e.g. pp 70, 76, 98 Mechanical ventilation refers to ventilation by means of an electric ventilator. It is more effective than natural ventilation but consumes energy.

Re-insulation e.g. pp 53, 103 Many renovation projects have focus on re-insulation. The investment is profitable in the short term but can also result in poor comfort if it stands alone.

Zoning e.g. pp 25, 31, 75 Buildings and cities are often divided into zones according to function. Several climate zones allows for a more accurate regulation of the indoor air quality â&#x20AC;&#x201C; and thus the energy consumption. DESIGN WITH KNOWLEDGE |

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Design with Knowledge New Research in Sustainable Building 1st edition, 1st impression 2012 © Henning Larsen Architects, Copenhagen, Denmark Editor : Signe Kongebro, Manager of Department of Sustainability, Associate Partner and Architect, Henning Larsen Architects Scientific research : Jakob Strømann-Andersen, MSc, PhD, Sustainability Engineer Martin Vraa Nielsen, MSc, PhD, Sustainability Engineer Michael Jørgensen, MSc, PhD student Texts and textual research : Farid Fellah, Josefine Lykke, Lise Mansfeldt Faurbjerg, Erik Holm-Hansson, Lisbet Fibiger Translation : Cecilie Qvistgaard Cover design and graphic layout : Philip Johansen Print : Formula A/S Bookbinder (special edition) : Co’libri, Malene Lerager ISBN 978-87-993081-3-2 Published by : Henning Larsen Architects – www.henninglarsen.com All illustrations are designed by Henning Larsen Architects if not otherwise mentioned. Photos and illustrations : Åke E :son Lindman (6, 86, 88, 93, 191) Martin Schubert (20, 22, 27, 191) Martin Stahl (34) Peter Andres Sattrup (37, 103) Signe Kongebro (100, 132) Mikkel Hune (55) Thorbjørn Hansen, Kontraframe (64, 66, 71, 188) Cordelia Ewerth (108, 112-113, 190) Thomas Borberg, Polfoto (118, 190) Agnete Schlichtkrull (126) Danish Technological Institute (134) GXN (136) 192 | DESIGN WITH KNOWLEDGE


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