Environmental retrofit of 1970s house

ENVIRONMENTAL RETROFIT OF 1970S HOUSE IN UNITED KINGDOM University of Westminster, faculty of architecture and environmental design Department of architecture MSc Architecture and Environmental Design Collaborative thesis with Scott Batty s Architecture 2018/2019 Semester 2 & 3 Thesis Project Environmental Retrofit 1970s house In United Kingdom Negin Esmailzadehhanjani September 2019

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Abstract

In recent years there has been a rapid increase in number of refurbished houses in UK. Yet even by having a big share of construction works there are few practices that take into consideration the importance of environmental approach in retrofit. Even recent Government’s programs and flexibilities in giving constructional permissions, especially for existing houses, has not yet made the way smoother for environmental retrofit.

Detached houses are one of the seven main UK residential building typology some dated back to 300 years ago. Refurbishment has been the main approach to maintain them and keep them habitable. The thesis aim is to identify, explore and compare capital costs and benefits of conscious refurbishment by evaluating an example in St. Albans, UK, that has been refurbished in 2018 with careful consideration of environmental strategies.

To assess the achievements of environmental passive strategies, in terms of energy consumption as well as capital costs of environmental refurbishment, the research initiated from conducting POE by considering before and after retrofit versions of the selected houses and the results were compared to what was derived from dynamic thermal simulations and ultimately conducting capital cost analysis.

Results has shown that the amount of success in implementing environmental strategies are mainly dependent on having a thorough understanding of environmental principles combined with a proficient abilities of designers to produce detailed drawings. Moreover this approach can reduce energy consumption by more than 61% in house while simultaneously shrink yearly energy consumption to almost half.

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Table of content ................................................................................................................................................................

1.

Introduction and summary .......................................................................................................... 7 1.1.

Summary of the issue ............................................................................................................ 8

1.1.1.

Climate change............................................................................................................... 9

1.1.

Government policies ............................................................................................................. 9

1.2.

Scope ................................................................................................................................... 10

1.3.

Significance of study ............................................................................................................ 11

1.4.

The purpose of the study .................................................................................................... 12

1.5................................................................................................................................................... 12

2.

3.

1.6.

Research questions ............................................................................................................. 12

1.7.

Research hypothesis............................................................................................................ 12

Methodology .............................................................................................................................. 13 2.1.

Introduction ......................................................................................................................... 14

2.2.

Literature review ................................................................................................................. 14

2.3.

Fieldwork ............................................................................................................................. 14

2.4.

Evaluation of the both simulation and fieldwork results .................................................... 14

Theoretical background ............................................................................................................. 14 3.1.

Literature review ................................................................................................................. 15

3.2.

Sustainable Design .............................................................................................................. 15

3.3.

Typology of UK Houses ........................................................................................................ 17

3.4.

Environmental strategies applicable in UK ......................................................................... 18

3.5.

Precedent ............................................................................................................................ 19

3.5.1.

Case one ....................................................................................................................... 19

3.5.2.

Case two ....................................................................................................................... 21

3.5.3.

Case Three .................................................................................................................... 24

3.5.4.

Case four ...................................................................................................................... 25

3.5.5.

Case five ....................................................................................................................... 26

Conclusions .................................................................................................................................... 27 4.

Field work studies ...................................................................................................................... 28 4.1.

Introduction ......................................................................................................................... 29

4.2.

Methodology ....................................................................................................................... 29 3

4.3.

Context ................................................................................................................................ 30

4.3.1.

Climate ......................................................................................................................... 31

4.3.2.

Future climate changes ................................................................................................ 32

4.4.

Introduction to fieldwork .................................................................................................... 34

4.4.1.

House 1 ........................................................................................................................ 35

4.4.2.

House 2 ........................................................................................................................ 41

4.5.

Limitation............................................................................................................................. 41

4.6.

Analysis ................................................................................................................................ 42

4.7.

Outcome .............................................................................................................................. 44

Conclusions .................................................................................................................................... 47 5.

Dynamic thermal simulations .................................................................................................... 48 5.1.

Introduction ......................................................................................................................... 49

5.2.

Methodology ....................................................................................................................... 49

5.3.

Construction and simulation gap ........................................................................................ 50

5.3.1.

5.4.

Calibration .................................................................................................................... 50

Analysis ................................................................................................................................ 51

5.4.1.

Solar space ................................................................................................................... 51

5.4.2.

Insulation...................................................................................................................... 59

5.4.3.

Role of each strategy in reducing heating load ........................................................... 62

5.5.

Energy consumption after the refurbishment .................................................................... 64

Conclusion ...................................................................................................................................... 65 6.

Cost analysis ............................................................................................................................... 66 6.1.

Introduction ......................................................................................................................... 67

6.2.

Capital cost analysis ............................................................................................................ 67

6.3.

Methodology ....................................................................................................................... 67

6.4.

Specification ........................................................................................................................ 68

6.5.

Costing scenarios ................................................................................................................. 71

Conclusion ...................................................................................................................................... 73 References.......................................................................................................................................... 75 Appendix ............................................................................................................................................ 81

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Acknowledgments

I would like to give my sincere thanks to Dr. Rosa Schiano-Phan with her efforts .Writing of this thesis would have not been possible without her guidance and support. Thank you so much Rosa for putting this course together and for all your pure care about not only environment but your students and also all the professors in this course who are trying so hard to educate architects about the environmental impacts of design.

Also I Would like to thank Dr.Joanna Goncalves and Juan Vallejo, Zhenhou Weng and all quest lecturer for all the time and patience they have put into our learning and all the energy they have put to educate us about environmental concepts also thanks to all my classmate they were all great people and I wish them all the best.

I want to also thank Scot batty for his guidance and collaboration and help for providing access and making the fieldwork stage smoother.

Also I want to thank my family for all their support and help especially their moral support.

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1.

Introduction and summary

This chapter will include a quick introduction about the issues that the thesis is trying to target and the Main scope of the thesis including:      

Summary of issue Government policies Scope Significance of study Research questions Research hypothesis

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1.1. Summary of the issue The ever increasing rate of population leading to more energy demand which is mostly the result of the misconception of many people about energy being inexhaustible. It is expected that by 2040 the population of the earth will grow and reach 9 billion people also with swift incline in the urbanization comparing to 1950 the population that are living in urban area is expected to be doubled by 2050 This will led to energy crisis in planet earth ( UN, 2019).

Figure 1–1 EU energy consumption by fuel type and global energy delivered by sector Source: https://grandsolarminimum.com/2018/11/19/world-energyconsumption/

Large increase in population and consumption of fossil fuel has brought more economic output. Human being has obtained grand growth yet whether this progression overweight the impact of unsustainable practices is questionable .This by itself can pressurize the ability of the planet to supply future generation needs (OECD, 2011).

The energy consumption has a direct contribution to nature degeneration.

Prolonged dependence on fossil fuel consumption has not only caused depletion in limited natural resources but also resulted in increase in emission of carbon dioxide.

Figure 1–2 Share of each sector in co2 emission source: https://www.buildinggreen.com/newsbrief/urgent-zero-carbon-buildingsneeded

Government and scientists have a general agreement that the climate change is the result of human activities. Concentration of the greenhouse gases especially carbon dioxide are increasing and if it not to be controlled, there will be irreversible damages on human beings lives and other occupants of this planet (Coyle et al, 2014).

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the economic prosperity rate of the country nevertheless complexity comes when scientists are proposing policies which will target energy reduction.

1.1.1. Climate change Amongst all impacts of CO2 increase, the main one which is the greenhouse effect has resulted in global warming. The urgent respond is to be made as it can be inferred from the three IPCC report that the earth temperature can rise by 3°C in this century (UNFCCC, n.d). Dry season rainfall reduction, sea level rise and frequency of natural disaster all known as climate change are the results of global warming to name but a few (Solomona and Plattnerb, 2008).

In Europe in recent year’s policies has been made to implement suggestions of the road map to 2050 for saving energy. In 2009 European policy makers have commissioned countries in EU to reduce GHGs by 50% by 2050 (EC, 2012).

Looking at energy consumption in EU, according to figure 1-1, 17.3% of energy in EU is used in household and residential sector. It is anticipated that floor space of household will incline by 29 % up to 2030, this means that, depending on the region and climate of countries, energy demand for space heating or cooling will incline sharply. Therefore the biggest share of the energy consumption in built environment will keep getting bigger and bigger everyday (EC, 2020).

As a wide spread belief most of economist do believe that reducing global emission will cost a lot and questions like what should be done and how quickly it should be done has remained unanswered. Different countries around the world start to target global warming by making policies for different energy consumer sectors (Henderson et al, 2018).

Moving to smaller scale, in UK, after transport the highest energy demand is for domestic usage for heating up the spaces (figure 1-3 and 1-4). In 2009, 25%, 18% and 19% of the total CO2 production was due to Water heating, lighting and appliances respectively.

In order to target this, government has come up with different strategies. In 2006 government decided that by 2016 all new homes generate as much energy as possible on site which seemed to be ambitious pledge.

According to 2008 act building industry must reduce carbon emissions by 34% up to 2020 and 80% till 2050 which not seems to be reachable (McPartland, 2017).

1.1. Government policies In order to degrade fossil fuel, as a primary source of energy, and ultimately target adverse climate changes effect, policy makers has tried to address the issue and reduce energy consumption and replace it with renewable energy.

Exerting a unified attitude toward energy consumption seems to be fairly hard since all the countries around word need to make sure that the energy supplies are enough to meet

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Similarly legislation has been made so that by 2020 new buildings will be zero carbon although there is less talking about 80% of the existing building stock, typical buildings that will still be around up to 2050. This is an interesting question which does not seem to have answer yet seems like a huge amount of construction work and properties in future have not been seen yet. One answer can be reusing existing building in the most sustainable way which is refurbishing and renovating.

and retrofit in the building industry (Coarse and Highfield, 2009).

Even in refurbishment methods has been used to alleviate or even reduce the amount of energy consumption in building with the main focus on reducing heating demand such as using double glazed or high efficient windows, continuous insulation (DBEIS, 2018) or even the idea of increasing the number of the users in the house. In other words increase the density through concepts such as houses with multi-generational use, cohabiting of the grand-children children and grandparents together which will lessen the impact on the environment, share resources and improve the quality of life.

Sustainability now is the word that everyone including designers, builders and contractors in the building industry will have at least encountered once during the building process. One way to target sustainability, is to recycle and reuse the existing resources as much as possible. By opting the refurbishment rather than new building and demolishing, a considerable amount of energy will be saved ultimately.

Yet it seems that retrofit and refurbishment are to be investigated more about its role and contribution to energy consumption reduction in building.

Attitude toward refurbishment has been significantly increased in UK not only because of the historical context of country1 but also for the financial advantages that can be obtained by opting for refurbishment rather than new building. According to statistics refurbishment cost 50 to 80 percent of the cost of new building.

Also the fact that it will be less time consuming approximately half to three quarter of the time needed for demolish and new construction. Moreover, Refurbishment now accounted for half of the construction industrial output, around 49% total work that has been done by the construction industry.

This signifies the position of refurbishment

Figure 1–3:UK detached house annual energy usage

1.2. Scope

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According to NHLE more than 500,000 building in UK are listed

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The main focus of this study is to investigate achievement of passive strategies in small scale residential building. Investigating the benefits that conscious refurbishment can have comparing to traditional ones both in terms of comfort of habitant and reduction in energy consumption.

Also the costs has been considered to see how much this strategies has added to the capital cost of retrofit. The results can be used to illustrate the long-run financial benefit of incorporating passive strategies.

This study is limited to retrofitted residential houses as well as the main energy used in houses for space heating and testing the passive strategies. In order to do so a 1970s detached house has been studied which has gone through retrofit already finished in 2018.

It is located in suburban area of London. This house has been proposed by the Scot Batty s architecture as a sample of environmental design.

Figure 1–4 UK detached house annual energy usage

1.3. Significance of study Investigating the implementation of passive strategies in residential houses can ultimately target more than half of energy which has been used in domestic sector. The thesis goal is to help designer being able to satisfy and convince costumers and contractors to implement these strategies also provide habitants with more environmental friendly ways to maintain living.

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- Long-run financial benefit of incorporating passive strategies

1.4. The purpose of the study Working in the small architectural offices make it harder to satisfy customers and contractor to bring any kind of environmental features to the project .Yet talking about these features from cost and benefit point of view can justify their implementation. The main purpose of the study is to evaluate implementation of eco-friendly features in existing house while doing retrofit.

Furthermore, try to make it possible for small practices to see the possibilities that these features can bring even to small projects.

1.6. Research hypothesis - If changes are to be done in terms of retrofit according to principles of environmental design the energy consumption of the house will reduce.

- It is expected that in long run the capital cost of the retrofit will be covered by the savings from the reduced energy consumption.

- It is anticipated that passive strategies that has been implemented in house will work properly for the purposes that are designed for

1.5. Research questions - understanding the performance of passive strategies - Energy analysis as handy instrument to determine the predicted function of the building - Using post occupancy evaluation to rate what these added feature has brought to the building - Interview with the architect to understand about the journey that the building went through - understanding whether doing these strategies according to principles will work or it differentiate case by case?

- What are the Major capital cost of retrofitting a detached house considering environmental aspects?

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2.

Methodology

This chapter includes the main steps of the research and how the questions from previous chapter are to be answered.

This chapter include:    

Introduction Literature review Fieldwork Evaluations and comparison

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occupants to record their daily occupancy time and their habits.

2.1. Introduction A three steps approach methodology has been used to answer the main questions of the thesis:

2.4. Evaluation of the both simulation and fieldwork results

- Literature review - Fieldwork - Analysis

In this stage it is important to assess the results from the field work to understand the existing situation and compare that with the outcome that has been driven from the simulation. Later simulations will be conducted by analysis of climate and microclimate following by dynamic thermal simulations using EDSL TAS as a main software.

2.2. Literature review Literature review in this thesis will compile accessible and related topics to the environmental design. It will also comprise references to principles thereby making a basis to compare the result of the design with what has been implemented in the proposed house.

Having known about the precedents, principles and also typical form of houses like the target one, the foundations of comparisons can be made. It is also essential to collect architectural drawing to differentiate the process of construction.

3.

Theoretical background

This chapter is literature review. Going more to details of sustainable design, its applicability to the residential houses. It will explore the typology of UK houses and environmental strategies applicable to UK context.

This chapter will include:

2.3. Fieldwork

   

According to oxford dictionary “fieldwork is a practical work that is being conducted in environment rather than laboratory”. In this case fieldwork will be separated in two parts.

First step is the interview with the owner of the house and the architect second part will comprise the post occupancy evaluation (POE).

POE conduction will include putting continuous temperature monitoring devices (data loggers) around the house in order to record indoor temperature, also asking 14

Literature review Sustainable design Typology of UK houses Environmental strategies in UK

quality of built environment and minimize their impact on the environment. Similar to other fields sustainable buildings are essential to stop effecting other creatures environment or even problems for future generation (Sodagar, 2008).

3.1. Literature review To understand the thermal function of the typical detached house in UK, its materials and passive strategies that has been used in this climate it is essential to go back and review literature.

This section will present information about:

According to Kilbert different terms has been used to address environmental design like green architecture, eco-friendly architecture and so on. However there is a mutual principles between them such as aiming to use indefinite sources of energy and new technology as logical as possible. It is important to know that technology should serve the design not vice versa and last but not least it should comply with economic and social situation of the context.

1: Typical materials and construction forms of the UK detached houses from 1950 to 1980 period.

2: Typical plan and form of the detached houses 3: Information about the main constructional details 4: Passive strategies that has been used or suggested.

Obviously the current approach of consumption and production is everything but sustainable. Developed and developing countries speed up the globalization with the aid of new technologies. In most of the industrial fields efforts has been made to address sustainability.

Design for sustainability cannot only increase quality and coherency with nature but also improve performance (Crul and Diehl, nd).

These steps will alleviate the way of understanding the existing form and materials as well as number of occupants and typical form of passive strategies that has been suggested or used according to UK climate necessities.

According to oxford dictionary sustainability means “meeting the needs of the present without compromising the ability of future generations to meet their own needs�. What has been missing from this definition is the role of human and other species living on the planet and has part in planet earth ecosystem (Kim and Rigdon, 1998).

To achieve a sustainable design, impact of the building should be considered as a whole which will include impacts that the building can have during its life span which in general is separated in 3 different categories. First one is the initial impact which is caused by design and construction the second impact is resulting from the annual heating, ventilation and cooling or either refurbishment and repairs and the final one is occurring during the deconstruction of the building (white paper, 2017).

Proper interpretation of sustainability in development and planning will lead to introducing proper approaches to maximize

Different approaches in different stage of construction can be used to target either initial impact or annual impact of the building.

3.2. Sustainable Design

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Starting from forming a good design brief continuing with recognition of needs and how the house will meet those.

- Type: type of activity, occupancy time, equipment and so on that is being used in building.

To target the second impact, passive and active measures are the ones that usually designers and architects takes into account.

Active ones are the methods or better than that systems which is used to achieve comfort while passive strategies are the ones that mainly target the building envelope to reduce energy demand.

- Tenure: who is benefiting from it and is going to invest.

- Age: age itself is not an indicator of the amount of work that needs to be done but helping to distinguish the construction element of the building and how it will limit the available choices.

- Condition: considering the condition especially for each element of the building and whether or not they are in poor state or in a good one or is there a collapse risk.

To be a successful eco-building, a building needs to adapt with climate and microclimate and that would not be possible but through an intact understanding of people, building, climate and their relationship with each other.

Yet it is crucial to consider the fact that reducing energy demand is simply a human behaviour and is an answer to this question “what temperature is considered to be comfortable�. However increasing energy efficiency is related to design a technology which can effect and be affected by cultural traditions.

- Historical significance and context: lastly the context that the building is in will have a direct impact on what can be done according to regulation and what cannot be done. It may seem that the older the building the hardest it gets to make them thermally comfortable yet in reality the traditional building seem to be more thermally adaptive ( Prasad and Penoyre, 2014).

It is not important that energy considerations is at the heart of one project or not, what is crucial is that in every step architect and designers consider each project as a way to modify and achieve maximum energy efficiency.

The decision of whether using passive or active strategies in retrofit, can be effected by designer’s choices, building type and finance yet for these there is a hierarchy. A hierarchical approach through sustainable design advocating the prevention of using extra energy should come first and using renewable energy as next and eventually trying to consume fossil fuel in the most efficient way as possible.

As mentioned before retrofit by itself is an environmental approach yet none of the retrofitted buildings can reduce energy consumption in all three fields not until when the building gone through what is called as a deep retrofit.

Passive and active strategies includes: Heat protection, direct solar gain and heat rejection, incorporating of each one is dependent on climate and building characteristics itself. Active strategies categorized in heat generation, heat

There are different variable while considering environmental retrofit below are some of them with brief description:

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dissipation and electricity (Thaleia and Alejandro).

Having the oldest dwelling stock in Europe, with 21% of the dwelling built before 1919 and 16% built from 1919 to 1945, an attitude toward retrofit and refurbishment has been stronger than anywhere else in EU. That is the reason why important to go through the history of the existing houses and the typology of the residential premises in UK.

All energy efficiency constructional plans are great for environment and economy it is the way to protect all domestic consumers.

It is important to briefly mention the retrofit, refurbishment and renovation meanings which will been used interchangeably from this stage on. These words are often used when a new system has been installed such as using double glaze.

Main category of UK houses are flats and house that distributing to detached and semidetached and bungalows with the distribution of 19% former and 81% later ones ( English Housing Survey, 2008).

Retrofitting means “providing something with a component or feature not fitted during manufacturing or adding something that it did not have when first constructed” (Eames, 2014).

From 1918 and by the Victorian expansion of railway it became possible to move material along the country. The main material that has been used in housing construction from that point up to even now are brick, timber, grout and in recent years steel and concrete for high raised building, especially after war from 1945 with prefabrication to target acute overcrowding of the houses.

Refurbishment is used when a process includes improvement of an element and renovation is used while turning something to good state.

From 1960s to 70s 425000 houses including towers, as a solution to housing needs, were built in UK this is the biggest residential construction number in UK history.

3.3. Typology of UK Houses In past two centuries UK has gone through alterations in technology, culture, society and so on. This has inevitably effected the housing context and features. Yet one third of the houses in UK dated back to wold war two and less than one-third has been built during the period when thermal regulations came in (Cassar, 2009).

Looking at the plan and special design of the houses from different period the phrases like” boxes for living “which was used before 1965 transformed in to 1970s properties which were more functional with lots of floor spaces.

Homes during this time do not have high floor to ceiling height or minimalist characteristics of modern era (NHBC, 2015). Benefitting from minimum overhangs, flush windows with introducing gas central heating system which made them free of fireplace and chimneys.

As moving forward engineers and architects are seeking ways to establish a generation of homes which are in harmony with 21st century needs. Sustainable design has already find its way to the residential sector which has resulted in transformation of existing and new homes.

Skylights became an inseparable part of these houses. They were supposed to make the house well-lit thereby lowering electricity bills. Furthermore these houses benefit from 17

huge rear and front gardens which is still one of the feature bringing attention to these houses. The effect of the architectural rebellion against traditional designs can be seen in these houses by Adapting to open plans, bigger kitchen, 1st floor and en-suite bath-room (Ideal home, 2015).

building site plays an important role in energy requirements of the building.

By understanding these two aspects heating and cooling loads can be targeted and ultimately reduced.

In UK, the aim is to maximize solar gain with balancing out heat loss through windows by using shutters and buffer zones. At same time trying to incorporate thermal mass which is officially the means of heat storage and controlling temperature fluctuations in room.

The main details of the houses form this period has been shown in figure 3-1.Roof trusses, concrete tiles with plastic guttering and some insulation. Most houses had cavity

Figure 3–1 typical details of houses from 1960s to 1980s source: NHBC, 2015

walls (block for inner leaf and brick for outer leaf) single glazed timber casement windows or horizontal sliding aluminium windows, concrete strip foundations are the main material that they inherit form mid -1960s houses.

With the technology progression, it is possible to incorporate high efficient windows in the right orientation which will correspond to the climate as well as better insulation in building with controlled resistant and air tightness.

According to Lebens (1980) north windows and roof cause large amount of heat loss while incorporating huge windows in south with double glazing will cause increasing thermal resistant which can be tackled by two main economical attractive ways such as night walls, curtains or drapes or external moveable insulation panels.

In order to maintain living in this houses or the ones before these minor to major amends and refurbishments has been done .According to English housing survey report (2008) there were around 23.7 million dwellings in England one fifth of this number is the houses that are built before 1919 and 75% of this are premises that had at least undergone major alterations as well as 43% of them having loft conversions or extensions added.

The larger temperature differences, between inside and outside, put another layer of importance on insulation as Yannas (1996) mention the effectiveness of thermal insulation is dependent on thickness and quality of material and largely on detailing to ensure continuity and avoid thermal bridges.

3.4. Environmental strategies applicable in UK Vernacular architecture is usually the best way to respond to environment also the

Lebens (1980) also propose that the insulation is better to be placed on the outside of 18

masonry walls so that this will allow them to act as primary or secondary thermal mass for this will bring them to the insulation envelope.

practice that has been participated in a research claimed that usually after the construction post occupancy evaluation is not conducted because of the lack of standardized proper guideline and the fact that it is a bit time consuming. This made finding a proper sample of post occupancy evaluation in small scale hard. Same issue is with finding of proper example of doing retrofit while considering environmental factors specifically in small residential houses.

Another important factor is air changes in building. As a rule , air change between inside and outside is happening due to pressure and temperature differences, some amount of this air change is inevitable because of the need of fresh air inside yet the rest which is happening through construction leaks is not desirable.

Using sealing techniques can reduce ventilation rate of the building to 0.2 ac/h which might be ideal for cold countries yet designers need to be careful about this rate since ventilation is directly connected to the air quality and might cause issues such as condensation (Nicholls, 2002).

3.5.1. Case one Case one is a work of ECD Architects, 1930s terrace house with 3 bed rooms located in south London. The existing situation of the house included double glaze low quality window, concrete flooring and loft which had flat roof and pitched roof benefiting from 25mm and 100 mm insulation respectively.

3.5. Precedent To develop any piece of architecture either huge projects or small ones, before design process, there will be a research targeting either the preferences of the client or on the needs of project which will then lead to forming a concept. The process of design usually include investigate and check precedent works and design and try to see positive and negative aspects of the case studies.

The precedent study can be categorized by samples of post occupancy evaluation in small residential houses and also passive strategies that has been used in common practices especially in retrofit and refurbishment.

In this case providing post occupancy evaluation of samples of environmental retrofit seems to be necessary. yet according to RIBA report (2014) eight architectural

Figure 3–2 1930s front and back picture source: http://www.greenspec.co.uk/building-design/retrofit-1930sterrace-house/

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By aiming for 80% reduction in energy usage the designers started from reducing the amount of heat loss through fabric2 and decline energy consumption of equipment.

This has enabled the property to use all the flushing water needed from the annual

Here are some of element s u-values - Suspended timber floor – 0.2 W/m2K - External walls – 0.15 W/m2K - Pitched or flat roofs – 0.1 W/m2K In this house the loft space was planned to be used as place for mechanical ventilation unit, so combination of insulation products has been used to cover joists rafters and party walls.

Overall the project aims were well insulating loft and extension and replacing windows with triple glazed one with warm edge spacers.

Also detailing has been considered as crucial aspect to keep the continuity of insulation and avoid any cold bridges.

Figure 3–3 source: http://www.greenspec.co.uk/buildingdesign/retrofit-1930s-terrace-house/

Average rainfall. Simultaneously sustainability has been considered in materials both internally and externally by taking into consideration that the chosen manufacturer has produced less toxic substance and the material itself is a durable material needing less maintenance. Internally the main focus is on volatile substances and trying to choose the materials that will have least off gassing.

This aspect gets bolder in the houses where infiltration is really low. Also the occupants were encourage to grow vegetables and plats in garden.

Whole heating system has been upgraded to new boiler and solar collectors are now the source of hot water.

Finally this house has achieved 80% reduction in CO2 emission. Including triple glazing windows accounted for third of CO2 production. The ultimate primarily energy usage is estimated at 67 kWH/m2/yr.

In terms of water efficiency, using rainwater harvesting which will have a tank stored underground and water being pumped to the header tank did not seem to be the good option for this property mainly because of maintenance and installation costs. Instead the final decision was to use a gravity-fed harvested system located above staircase.

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Final cost evaluation has shown that there will be around 85% energy reduction with saving of 600£ per year.

(Sustainable refurbishment of housing, Yates, BRE Press, 2006)

By Increasing the resistance of materials

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Victorian

3.5.2. Case two Second case study is looking at the analysis that has been done by Neroutsou and Croxford (2014) a Victorian semi-detached house located in London built before 1919 going through retrofit from June to December 2006.

The work that has been done include 220mm insulation with 50 to 100 mm thickness, using 100 mm Rockwool between rafters of the roof, replacing floor boards , all the kitchen and attic being insulated with Rockwool in between joist, all windows being upgraded to double glazed window and rare living door was equipped with triple glazed.

The improvement in u-values of the different scenarios that has been used to evaluate the house has been shown in table 1. The base of this study was on three case scenarios by using EDSL TAS software considering current refurbished house, before refurbishment and using Passiv-haus criteria.

Figure 3–4 House picture from front source: https://ars-els-cdncom.ezproxy.westminster.ac.uk/content/image/1-s2.0S0378778816305291-gr1_lrg.jpg

In this study a case in which Part L1 B was the main target has been compared to hypothetical refurbishment complying with Passive House (EnerPHit).

Here are the comparisons that has been done in terms of heating loads.

(Neroutsoua and Croxford, 2016)

Figure 3–5: Plan of the house source: https://ars-els-cdncom.ezproxy.westminster.ac.uk/content/image/1-s2.0S0378778816305291-gr1_lrg.jpg

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External Wall − Front Facade External Walls Party Wall Attic Wall Roof Attic Floor Intermediate Floor Kitchen Floor Hall Floor Living room Floor Windows

Pre refurbishment 1.24 1.24 0.73 2.17 3.11 2.27 2.06 0.96 0.96 0.78 4.80

Current state 0.32 0.5/0.32 0.73 0.24 0.20 0.35 2.06 0.32 0.96 0.18 0.8/1.7/2.1

Table 1: U values (W/m2K) of different scenarios.

Figure 3–6 Energy use breakdown (KWh/m2a).

Source: https://www-sciencedirect-com.ezproxy.westminster.ac.uk/science/article/pii/S0378778816305291

Figure 3–7 Heating loads (kWh/m2) and retrofit measures. Source: https://www-sciencedirect-com.ezproxy.westminster.ac.uk /science/article/pie/S0378778816305291

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EnerPHit 0.13 0.13 0.21 0.14 0.13 0.35 2.06 0.15 0.15 0.134 0.8

External Wall Insulation Before (KWh/m2)

Party Ground Attic Windows Roof Air wall floor floor and Skylights Insulation tightness Insulation Insulation insulation Doors

146.0

120.3

120.2

91.2

88.0

86.8

61.0

After(KWh/m2) 120.3

120.2

91.2

88.0

86.8

61.0

48.3

Difference (KWh/m2)

−0.1

−29.0

−3.2

−1.2

−25.8

−12.7

−25.7

Table 2 Retrofit measures’ effect on heating loads. Source: https://www-sciencedirectcom.ezproxy.westminster.ac.u k/science/article/pii/S 03787 788163052 1

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3.5.3. Case Three Third case study is a house in oxford benefiting from natural and renewable material for insulation, energy efficient underfloor heating with thermal mass walls and flooring and energy efficient lighting and appliances.

This house is a solid stone cottage aiming for low carbon emission refurbishment by reusing natural materials renewable energy resources.

Figure 3–8 : oxford house picture from the front of the house source: http://www.ecovation.org.uk/htmldesigns/ecovationopenday.html

Moreover there was a careful plan to do the detailing of vapour- permeable insulation of flooring, walls and roof. The insulation solution that has been used in this example can be a good precedent for all solid wall home which has the share of around 7-9 million houses in UK.

Main strategies: - Minimising energy lost through fabric - Using renewable energy resources - Installing energy efficient heating and lighting appliances - reuse and reclaim existing material - High efficient heating system Decisions which has been made for this refurbishment has reduced the final energy consumption of the house by 58% (Roaf, 2013).

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3.5.4. Case four The fourth case is conversion of the barn to a house. They are numerous agricultural and industrial building in cities or sub urban areas that has not been used for so many years so it will be waste of money and energy to demolish and rebuilt them. These building usually are made of brick and stone which are uneconomical for construction field today.

The Crossgar project was an experiment to test how to reuse these structures also consuming second hand materials to save overall embodied energy and the timber was provided locally. A conservatory has been built to drive passive solar benefits. Rainwater recycling and grey water treatment is another strategy in this project. The main purpose of the project was to avoid wastage and use every scrap of the wood and stone.

There isn’t any post occupancy or more information about the project success rate yet it was worth mentioning here because of the fact that refurbishment can also enable architects to reuse old buildings and change their usage.

Figure 3–9 Rachel Bevan architecture, old mill. Crossgar source: http://www.bevanarchitects.com/projects/awardwinningandpublis hed/oldmill/

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3.5.5. Case five Fifth case study is an oxford eco-house a three-story detached house in a north-south alignment site. The difference between this case and the previous ones is the fact that this house was originally built to be eco-house yet it is worth mentioning because of numerous passive strategies as well as active ones that has been incorporated in this house.

It was built with cavity wall system originally.

The main aim of the design was minimum carbon emission. This was achieved through heavy construction, careful selection of the materials and also buffer spaces in back and front of the house with the main purpose of keeping damp cloths inside them.

Figure 3–10 Oxford eco house source: http://gbezine.greenbuilding.co.uk/the-oxford-ecohouse-timelessand-iconic/

Main strategies: - Careful material selection in wall - Precise detailing - Wall, floor and roof insulation - Sun space at both sides - Using renewable energy sources such as photovoltaics solar panels Using small vents in buffer spaces provide a good quality natural ventilation also the buffer spaces itself made a huge impact on the performance of the house, thermal mass has help to stabilize indoor temperature, triple glazed window help the overall building performance (Roaf, 2013).

Figure 3–11 Oxford eco house strategies source: http://www.ideaarchitecture.org/_buildings/b_119/conc/_zoom/zoom_01.htm

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Conclusions Combined together, literature review, sustainable design, typology of UK houses and environmental strategies that are applicable in UK draw attention to need of considering sustainable approach even in small refurbishment projects. In UK there has been always more attention to providing comfort in the building in cold seasons yet the climate change should bring designers attention to the hot seasons as well.

From the precedents of environmental retrofit, it can be inferred that upgrading windows and insulating walls and floor will always come first then additional strategies such as sunspace, environmental friendly materials, and upgrading heating system.

27

4.

Field work studies

This chapter is explaining the field work process and the results that has been inferred from it. It will start from explaining the context and the climate followed by the features of selected houses and final outcomes.

This chapter will include:      

Introduction Context Introduction to the houses Limitations Analysis Outcome

28

Post occupancy will illustrate the extent of project success as well as enabling designers to identify essential improvement.

Benefits:  Getting feedback on the performance of the building  To help building operator to manage the building  Getting feedbacks which will help future projects  To identify and reduce performance gap (Ward and Agha-hossien, 2016).

4.1. Introduction In this study the field work will be done inside of the Barncroft house 1 and 2. This houses has been introduced by Scott Battys architecture which is a renovated detached house and, its former version, neighbour house.

It is also important to mention both houses are dated back to 1970 they have exact same plan and volume and also orientation.

The occupant are given a schedule to record their daily affairs. Yet access to the former version of the house is limited because of the approval needed from the owner.

The fieldwork was initially intended to be done both for cold and hot season yet because of limited time of doing research it will include results of 24 days in cold time of the year. It will mainly focus on the effect of the passive strategies that has been implemented.

Step one: Identifying what exactly is the POE role in this project.

- POE is the crucial step in this project to see the differences between existing situations of the building compared to what it was expected from the building to achieve before construction.

- It will evaluate the role of passive strategies and how they operate

4.2. Methodology It is important to go through literature about POE to explain the methodology and the steps. Post occupancy evaluation can be effected by culture and how it has been utilized in different region and accordingly gets its meaning.

In all definition a mutual aspect of POE is that it is a systematic data collection, analysis and comparisons to evaluate the building which has been occupied for some time. The RIBA add to this definition the benefits that POE can have for architects which is getting more information about their design function and it helps to see what designers and engineers already have done (Hariri and Crozier, 2008).

Step two: Try to identify the target spaces - Evaluating the spaces that are supposedly benefit from the passive strategies.

Step three: Brief the POE - Timing: Almost a month - People who is responsible to conduct POE: student - People who is involved: occupant 29

- The equipment that will be used is data loggers to do continuous temperature monitoring

4.3. Context Both houses located in UK sub urban area of London called St. Albans , in fairly low dense residential part .The history of this area goes back to 20 BC when a tribe started to build their capital there back then the context of this town included wooden huts with thatched roofs. From then up to now there were ups and downs in history of prosperity of this town. Right after world war many industries has been attracted to that part of city yet in 20th century it remained as a commuter’s town. In 21st century it is still flourishing with 6300 population (lambert, nd).

Data which has been gathered from the field work will then be analysed and compared with the generic data produced by dynamic simulation and analysis done by EDSL.TAS software to reconcile the predicted performance of the building and its achievement through the implemented passive strategies. Also to compare the existing situation with previous version of the house and identify the improvements.

Figure 4–1 : St Albans location and location of the both houses map. Source: Google map

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London climate records are available form 1659 which is showing that form 1919 it has become warmer since autumns having milder weather. Today London climate is similar to south east England with mild temperature in winter and summer the average day time temperature is around 11 °C with 5.5 °C in January and 18°C in July additionally it has 200 dry days out of 365 and a precipitation of 585mm (Clout et al., 2017)

4.3.1. Climate With having a temperate climate, the climate which is influenced by oceans, UK seldom gets extremely hot or cold. In general it has wet and warm summers and winters. Also the changes in weather conditions are very probable. Inside United Kingdom different parts have different climate features for instance Cumbria in north-west has more rainfall and cooler temperature comparing to London in south east with cold and dry climate in winter yet warm and dry climate in summer (BBC report, 2019).

Here are some of the information about London climate which will be related to the thesis subject.

Temperature in United Kingdom is dedicated to latitude in general south east being the warmest area while the temperature gets less and less moving to the north. Prevailing wind is coming from the south west while four other direction with less powerful winds (SYM Ltd, 2018).

Figure 4–2 UK wind map and UK climate regional climate. Source: https://www.bbc.co.uk/bitesize/guides/zjk7hyc/revision/1

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In first figure all average climate data is shown. It is indicating that mid-May to midAugust the average will go above 20 °C calling for cooling strategies while rest of the year the average temperature is less than 15 °C going even below 10 °C between November to January indicating that cold seasons are more important and will prolong more in London climate.

emission will continue to be the same this number will hit 5 °C by the end of this century (London environmental strategy, 2017).

Under UNFCC Paris agreement of 2015 many countries including UK agreed on keeping global temperature changes to 2 °C (NIC, 2016).

To put another layer of importance on heating strategies and going more to the details figure 4-4 is showing average horizontal radiation with maximum rate happening in July and minimum horizontal sun incident in December.

When it comes to vertical radiation (figure 45) north gets least of sun radiation throughout the year. In spite of the fact that south is receiving the highest radiation in cold months during the hot months of the year (mid-April to mid-August) east and west faced surfaces will get the highest solar radiation.

4.3.2. Future climate changes The site is locating close to the London as one of the main international centre of financial trade which has made it the most vulnerable part of UK to climate changes. Its location is already in drier south east of England. As in the London micro climate within and between sectors will also alter. The UK climate risk assessment calls for immediate changes to be made in areas such as built environment (CCRA, 2012).

London as one of the biggest growing cities in world encounter pressures to improve the infrastructure, services, wellbeing and prosperity of Londoners. Average global temperature has increased by 1 °C since 1850 in this city if the trend of greenhouse gases 32

30.00

DBT mean min

25.00

Global Horizontal Radiation

20.00

Wind Velocity

15.00

DBT mean average

10.00

ASHRAE-55 Adpative Comfort - 80% acceptability

oC

kW/m2

m/s

DBT mean max

5.00 0.00 Jan

Feb Mar Apr May Jun

Jul

Aug Sep

Oct Nov Dec

Figure 4–3 Monthly average climate data. Source: Meteonorm weather data

6.00 5.00

kW/m2

4.00 Global

3.00

Diffuse 2.00 1.00 0.00 Jan

Feb Mar Apr May Jun

Jul

Aug Sep Oct Nov Dec

Figure 4–4: Daily average horizontal radiation source: Meteonorm weather data

3.50 3.00 2.50 North

kWh/m2

2.00

East 1.50

South

1.00

West

0.50 0.00 Jan Feb Mar Apr May Jun

Jul

Aug Sep Oct Nov Dec

Figure 4–5: Monthly average global vertical radiation source: Meteonorm weather data

33

According to LCCP report (2002) in future cold winters will become fairly rare in UK and in general the climate will be warmer. The probability of having hot summer days will increase to more than 10 days per summer with the average temperature higher than 33 ºC. It is expected that this situation get worse in big cities with another 5 ºC to 6 ºC incline in the temperature. This implies more energy usage in summer for cooling and ultimately calling for passive strategies in built environment targeting that.

As mentioned before the house that has been introduced to evaluate in this thesis is 1970s detached house located in St. Albans. In this thesis house one is the above house, named to enable reader to distinguish between target house and the neighbour house and is the exact original version of the target house.

4.4. Introduction to fieldwork This section consist of brief summary about the house itself and how the fieldwork has been implemented. Also including more detailed information about the passive strategies’ that the architect has implemented.

Green Field

House 1

House 2

Figure 4–6: Location of the houses source: Google map

34

Barn

4.4.1. House 1 A two story detached house form 1970s with planning typology coming from the similar era. Open plan consisting common space in first floor, rooms and more of private spaces in second floor. The area of the house is 112 m2 for ground floor and 70 m2 for the first floor.

One project can include retrofit, renovation and refurbishment simultaneously this is the case with house one.

Figure 4–7 House 1 front elevation Figure 4–9 house 1 rare elevation

The whole process of retrofit and refurbishment has been separated by architect in two phases. First stage has been already finished in September 2018.it is not the typical form of refurbishment being done with different practices due to the reasons below.

Windows Windows area is usually between 5 to 10 % of total surface area of the houses yet they usually are responsible for up to 30 % of the energy loss. First stage is to target windows and doors and upgrading them to double glazed high efficient ones (Hydro, nd). In older properties with wooden frame around windows loosing heat through it can be even more.

Figure 4–8 House 1 front view

In the house the whole windows has been upgraded to argon filled double glazed windows with the u- values 3of 1.4 W/m²K also the area of the windows in whole house has been increased by adding new window to the east room, openable glass door for the rare extensions and roof lights added above the staircase area and in one of the rooms.

Figure 4–9 House one entrance

3 One the main features of the window is U-Value which usually accounts for the amount of heat that will be lost through the window.

35

Insulation According to NIA (2010 to 2019) usually 25 % of the heat lost is through roof it is recommended to insulate the roof up to 27 cm.

asked for the reason of doing so the answer was “It felt colder upstairs than ground floor”.

Moreover the architect main aim was to keep the facades and the general look of the house as it was before and not to alter the main characteristics of 1970s house by keeping the cladding to the first floor.

Most of the houses in UK have either a cavity or solid wall. A cavity wall can loss more than 35 % of the heat in the house if the solid wall is used without the insulation this amount can be doubled.

Also House one is already benefitting from the cavity wall which has been insulated yet the designer approach was to add another layer of insulation below cladding on the façade of the first floor. This layer will be attached to the existing façade of the building and be covered by the final finish this will not only allow the house to have fresh new look but also is easier to install, will not affect floor area of the building and will reduce damp since the wall is no longer the cold surface. Furthermore all cavity walls around the house has been injected with insulation, therefore first floor benefits from double insulation both inside the cavity wall and on the outside surface.

Solar radiation and infrared emission are two main factors that can effect heat transfer through roof and vertical walls yet the dominance of them is less in the walls comparing to the roof. The difference is because of the fact that the roof has more area facing atmosphere therefore it is more prone to lose heat through infrared radiation.

Convection lost is dependent on the prevailing wind direction usually walls facing up wind direction lose more followed by roof and side walls and downwind walls (Álvarez, 2016).

Second strategy was to equip the house with continuous insulation going around the first floor and roof of the house to make an envelope which is called as Tea cosy by the designer. Occupant and architect has been

Moreover more than 15% of the heat inside the building can be lost through floors this amount will increase in the extensions. In the extension floor of the house in east part the insulation thickness goes up to 0.20m.

Figure 4–100: House 1 insulation line source: Scott batty s architecture

36

Sun space

In all these systems that are based on solar access the best orientation in north equator is south with highest vertical radiation incidence in cold seasons. The glass should be a transparent glass with low emissivity, these systems are called as indirect-gain ones which works on getting the short wave length and higher U.V radiation getting through the transparent panel and heating the air through conduction which is the basis of greenhouse effect ( Sharma and Gopta, 2015).

The building research establishment has announced that solar gains in UK house already contributes to about 15 % of the heating loads in houses (Woolley, 1997).

As a third passive strategy the designer has allocated space in east part of building as a sun space which is supposed to provide hot air through a window to the rooms and can be called as solar chimney.

According to Ong and Chow (2003) solar chimney is a space which has one or more transparent wall. The process starts with solar energy heating up the air and difference in air density make the air move.

The concept is similar to Trombe wall yet solar chimney is designed to provide ventilation in building during day time. Providing natural ventilation is another benefit of sun chimney.

Natural ventilation has been used extensively specifically in recent years for it will reduce the energy consumption.

Figure 4–11: Cross section: solar space area function in winter days

Figure 4–12: Cross section solar space area function in summer

37

As pictures are showing this space has around 1.4 m2 area and 4.4 m height. The whole east façade of the space is cover by double glazed tinted window and a window with area of 70 cm2 in the first floor connecting the space to the occupied area of the first floor. The whole space is located at the top of the entrance in the ground floor which has been separated with internal door from the small hall in ground floor. This strategy is supposed to effect three main occupied spaces the sitting room in ground floor and tone bedroom and a bathroom in the first floor.

Figure 4–12 Sun space from outside east elevation

The main idea of this sun space was coming from an American architect s 4sketch which enables the space to work for both summer and winter. As it has been shown in figure 411 solar area is supposed to provide hot air for the adjacent spaces while opening the window5 connecting this space to occupied areas in first floor. As for winter nights by closing door and window this space is supposed to work as a buffer zone to delay heat lost.

Figure 4–14 Sun space internal window to the bathroom

As mentioned before in near future there will be an increase in temperature calling for cooling strategies as well. Hot air is prone to move upward, by putting an extra window in the roof this air will be extracted and if the cross windows will be open this can initiate cross ventilation in the house.

Figure 4–15 New rare elevation (Source of all pictures above is Scott batty s architecture architecture)

4

5

Dennis Holloway

This is the window which bring the air to the occupied areas in the first floor

38

Careful detailing

As stated in first chapter with the ever increasing rate of population, there is an acute need to increase the number of homes which are affordable and sustainable. Today concepts such as multi-generational houses, co-living and co-housing ideas has become a concept which allocate available spaces to more people. According to night frank report both of these ideas has a long history.

Communal living (co-living) concept dated back to seventeenth century especially after world war two it became a solution to address economic restrictions.

As Plunkett mention (2015) “successful interior design depends on sound construction and beautiful detailing. Creative conceptual thinking depends on creative practical thinking if the sprite of a project is to be successfully expressed in the finished building.�

The other feature of the house is that the construction was done by the constant presence of the architect making one to one details to enable the contactors and builders readings easier. The main objective was to make the final construction as close as possible to concepts of the architect and avoid any cold bridges and gaps. This is called as production drawings or working drawings which will provide builders and contractors comprehensive idea of drawings and the quality of work that is needed.

Co-living will enhance social health of society, making affordable houses for younger generation, also it is the idea of having more with less which means less menace for environment.

In twenty first century the generation of young people that are unable to afford a house is less than before. New research has shown that many families like the idea of availability of new multigenerational homes that can accommodate young and old generation of the family under one roof.

A house for generations All the solutions and strategies mentioned above is already implemented in phase one of the project. In phase two the idea is to join garage to the house as a living space for future generation of the family. This part will share communal and services areas with the main house yet with the different entrance and ensuit room.

Figure 4–16 Detailing process source: Scott batty s architecture

39

New findings has suggested that almost 70% of the UK household are multigenerational usually this type of the houses has three up to four room that make them suitable for different generation of the family ( NHBC, 2017).

Upgrading the heating system The heating system of the house has been also upgraded, changing existing open loop to a close loop and using new boiler with high insulated cylinder. The boiler has been put as close as possible to the cylinder making the heat lost through the pipes minimum. Yet these changes has not been considered in simulations and during thesis except for the part that the energy bills has been monitored.

Figure 4–17: 3D view of the house and with ground floor and roof plans source: Scott batty’s architecture

40

4.4.2. House 2 House two (figure 4-18) is the neighbour’s house with the exact shape and outside materials of the older version of the retrofitted house. The plan of the both first and second floor is the exactly the same except for the fact that this house has a conservatory at the west part (rear garden) while House one (retrofitted house) has an extension in back. This house has been used during field work to see the respond of both old and new version of the house to similar weather condition.

4.5. Limitation The limitation of the study are: - In house 2 the occupant has turn the heating system on during the POE period - The occupants were asked to record their daily presence inside the house yet the presence of occupant inside each room separately has not been recorded - Since the thesis time was 6 month the time of the study is limited to 24 days fairly cold season.

- Because of the unavailability of the house 2 occupant’s continuous temperature monitoring devices installed later than the first house yet still providing 24 days of monitoring results.

Figure 4–13 house two plans and front elevation source: Scott batty s architecture

41

4.6. Analysis The analysis has been done from 12 April 2019 to 15 May 2019. It started form collecting data logger and extracting data form them and try to make a logical connection between the results and the occupation log that the occupants has kindly provided. These data will especially be useful for the calibration in dynamic thermal simulations.

Figure 4–19: Sample of occupation log

42

2

Figure 4-20 and 4-21 are showing location of data loggers in both houses to monitor temperature during the specified period.

3

The main aim of putting data logger in different locations:

1

- At the top and bottom of the sun space to understand the temperature differences between top and bottom of the space - In dinning and sitting area to see the effect of the large windows

First Floor Plan 1. Bottom of solar chimney 2. Dining Room 3. Sitting area

- In second floor double bedroom to check the relationship between the temperature of this room and sun space

5 6 7

- In staircase to check the effect of large roof light

4

- In north-east bedroom to check the effect of the window

Second Floor Plan 4. Top of solar chimney 5. Top of Stair Case 6. Single bedroom 7. Double bedroom

Data logger’s location

Effected areas Solar Chimney Less affected area Chimney Figure 4–20 Data logger’s location in section and plan

Figure 4–21 location of the data loggers

43

4.7. Outcome Also the deductions has been separated in two parts, first showing the average temperature difference between the floor covered by insulation and second one is comparing the top and bottom of the sun space area to check if temperature difference which is essential for air movement is occurring.

Expected results Expected outcomes can be categorized in two: First one is that resultant temperature will rise while thermosiphon effect is happening in sun space. Second one is less heat loss and more constant temperature with new windows and continuous insulation.

It is crucial to mention that the trend of the occupancy during these days were mostly like: the house being occupied usually after 5 PM to 6:30 AM additionally during 5 days of this period one person was constantly inside house one.

In temperate climate like London with almost cold winter it is crucial to stabilize temperature especially in cold seasons to reduce energy demand. This study may result in interesting results that by using simple passive strategies it is possible to target that goal.

Since data that has been collected form Data logger was hourly for 24 hours of 24 days, the best way to show the average results of the occupied space was to separate first and second floor and try to get the average temperature of the spaces in 24 days of the that the fieldwork has been done.

Outcome In this section fieldwork results from the house one has been shown. It is important to mention that the results from house two will be plotted on the same graph with dynamic thermal simulation results to make the readings easier.

20.5

20 19.5 19 Dry Bulb-Temperature °C

18.5 18 17.5 17 16.5 16 Space 5

Space 7

Space 6

Graph 1: Average temperature of the first and second floor

44

space 2

Space 3

As it is shown in graph one in general the average temperature of the 1st floor spaces are higher than the ground floor. In general the average DBT temperature of the first floor benefitting from the insulation was 1.47 °C higher. It is also important to mention that the average DBT temperature of the outside during this period was fluctuating between minimum 5 °C during the night up to maximum 18 °C during the day.

It can be deducted from graph two that the second floor of house one has close temperature to same floor of house two where the heating system was on with around 0.5 °C to 0.7°C difference. Whereas in the ground floor space the DBT difference is almost 2 °C.

As mentioned before occupants of the both houses were asked to turn the heating system off during fieldwork period yet this was not possible for house two. In fact this has given the opportunity of comparing the retrofitted free running version of house to the old house with the heating system being on.

Graph three is plotting the results from data loggers which was located at the top and bottom of sun space for four consecutive days consisting both sunny and cloudy days. As it can be seen in the graph temperature difference is happening in the sun space.

Graph 3: Comparison of the average temparature in house 1 and house 2

21 19 17

Dry Bulb-Temperature °C

15 13 11 9 7 5 3 1 space 6

space 7

First floor

House one

Ground floor

House two

Graph 2: House one and two spaces, DBT temperature comparison

45

space 3

Yet this graph can raise two more questions first one is about the fact the trend is the same during night and days which shouldn’t be the case with the insulated wall in the bottom and glassy façade at the top which make the heat lost duration different. Second issue comes with the fact that during cloudy days, with less radiation, although the highest and lowest points dropped yet the temperature difference of the top and bottom part still remained between 1.5°C to 2.5°C which is like sunny days with more radiation coming inside .More investigation has been done in the dynamic thermal simulation to answer these doubts.

25

20

Dry Bulb-Temperature °C

15

10

5

Time

0

00:00 06:00 12:00 18:00 00:00 06:00 12:00 18:00 00:00 06:00 12:00 18:00 12:00 06:00 12:00 18:00 00:00

outside temperature

Top of sun space

Graph 3 : DBT Results from top and bottom of sun space for four days

46

Bottom of sun space

- Although the temperature difference is happing between top and bottom of sunspace the similar day-night trend and no differences between cloudy - sunny days brought about some questions.

Conclusions Comparing each one of environmental strategies that has been used in house one showed that all the aspects of these strategies has been made according to principals from the extra layer of insulation on the outside layer to careful consideration of details.

Although sunspace orientation and transparency of its glassy faรงade is not as precise as it should be from the principles. Yet according to architect, the main reasons to do it in a way it is was the difficulties in getting planning permissions.

These conclusions and questions make a foundation of further investigation in next chapter.

Also the window above the space which was mentioned in the sketches has finally omitted during the construction phase from the building and replaced by fan with thermostat to evacuate the air when the temperature inside the space gets more than specific amount.

Fieldwork has help to investigate the role of insulation in house one properly the average temperature of the space and the comparison that has been made by comparing DBT during 24 days can bring numerous conclusion confirming the positive role of insulation and simultaneously questions: -The average temperature of the spaces located in the well-insulated zones is higher than less insulated ones during the 24 days fieldwork.

- The comparison between house two (neighbour house) and house one (target house) has shown that free running retrofitted one (house one) can maintain constant similar temperature of house two with the heating system being on.

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5.

Dynamic thermal simulations

This chapter will include the simulation that has been done in order to answer question from previous chapter and illustrate the gap between simulation and construction. Each aspect of house one has been investigated separately. It is crucial to mention that for each aspect optimization has been done by considering the fact that all the proposition should be in a way that can be installed and placed in a an environmental retrofit.

This chapter include:     

Introduction Construction and simulation gap Analysis Methodology Energy consumption

48

5.1. Introduction

5.2. Methodology

First step to find weaknesses and try to propose improvements is evaluating the quality of the existing building. Building respond to the environment can be examined hourly and very detailed through simulations.

With little innovative, simulation are not only capable of considering all inputs but also enables users to get output step by step and in the format that is needed.

The choice of simulation tools will be a strategic decision. In this thesis the software that has been used is EDSL TAS software.

In other to get the deductions as close as possible to reality these steps has been done: Step one It has been tried to make the model with exact same dimensions which the real house has.

Similarly zoning has been done according to different usage of each space and room and also according to the main focus areas of the thesis.

Advanced analysis can be achieved through dynamic thermal simulations and analysis of each component of the building like, windows, shades, orientation and different systems.

Step two

Since the results of the field work was from the time of the year when there is a need for heating system, the simulation in this chapter will include heating load, thermal comfort and different scenarios which will show the effect of each strategy separately for cold month.

Doing calibration, which is making the internal gains and conditions as close as the reality during measured period. Additionally the weather data that has been put in the software has been change according to closest weather data station to location of houses to make the external conditions similar.

In any thermal simulation project, it is essential to make the model as simple as possible this helps narrow down the analysis results as well as being less time consuming.

Moreover, there are some inputs like internal gains, materials, opening s percentage and occupancy profile which will reflect the condition of the model. Meanwhile model will be effected by environmental factors which will be defined by weather data file.

Step three Since the results from EDSL TAS is endless the main focus is on internal Dry bulb temperature, heating load and frequency of overheating.

Step four It is combined with step three in a way that after identifying issues or positive aspect there will be a proposition to optimize each strategy.

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5.3.1. Calibration

5.3. Construction and simulation gap

To address all aspects of energy consumption there is a need to do the whole building simulation which can closely render the actual behaviour of the building. This type of thermal modelling incorporate calibration techniques which make the operating condition as close as possible to reality and will hopefully make virtual thermal model results more reliable. In this way, the underlying reasons of any malfunction can be better targeted (Dronkelaar, 2016).

Notable gap can usually be recognized by monitoring building performance after construction, which is showing difference between predicted and actual energy usage of the building. Usually building using 1.5 to 2 times more energy than their predicted consumption. Up to this date, most of energy performance gap analysis main focus is on the non-domestic building. Identifying this gap will show the final industry product weakness (Jones et al, 2015).

According to Holly W. (2015) the professional practices usually use calibration by including unregulated load, revising plug loads, occupancy profile and actual weather data as an input. The accuracy of calibration is dependent on how much data has been collected. The main usage of calibration is to safeguard that the building function in the model will be as it was intended to be.

Baseline building performance will not illustrate the actual energy consumption and environmental behaviour of the building this is due to the constant relationship between the building and surrounding (ASHREA, 2014).

In fact, modelled building will never represent the reality yet it is useful in a way that it will help architects to understand performance gap and how energy model’s results are different from the ones measured in reality (Dronkelaar, 2016).

The type of calibration that has been used in this thesis is more evidence base meaning it is based on updating weather data measurements and occupant’s profile.

From the previous stage, fieldwork analysis, there were some question that arose, are to be answered in this chapter.

Since it was not possible in this thesis to ask both household to record their exact time of using lights or electrical appliances or their attendance inside each one of the rooms. The type of calibration is as Holly W. (2015) named “partial-calibration”.

This step is to alleviate narrowing down the indefinite information that is possible to achieve and put highlight on the results from the spaces that can help with the aim of the project.

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part with glassy façade material. As Lebens said “Thermal mass is the means of heat storage and air temperature stabilization.”

5.4. Analysis 5.4.1. Solar space Air movement will happen when the cold air and hot air move. The buoyancy force will happen with specific height difference and when there is temperature differences.

Accordingly, the potential for air movement will happen with the existence of three main elements size of opening, difference in height of inlet and outlet and temperature difference (Wahab et al., 2016).

Each one of this aspect has been taken into consideration to help to move one step forward and do the optimization.

Figure 5–1 position of the data logger inside the solar space, occupancy profile and weather condition

For analysis calibration has been done and the weather data and user profile has been changed according to the reality of the days that the fieldwork was implemented.

Before 5PM

After 5PM

House 1

As mentioned before analysis started form getting deep into the questions that has been risen by fieldwork analysis.

House 2

Therefore the room in the first floor located in south west, as the room which is indirectly benefiting from the solar chimney, is the main target. Furthermore, the house two analysis of the same room both in simulation and fieldwork has been plot on the same graphs to make the comparison more straightforward.

Temperature difference Graph four is showing a result for a typical sunny day in May and the behaviour of the sun space during 24 hours. The result of the fieldwork and simulation are close with the maximum difference of 1.4 °C differences. As it was expected the temperature of the bottom part with being surrounded by solid insulated wall is more constant than the top 51

X3

According to the occupant log the window to the occupied space were open during the measurements. The temperature difference is fluctuating between 0.3 to 2 °C. Graph 3 confirmed the existence of air temperature difference inside the space when sun shines outside.

Questions that statement:

are

following

above

- How many days - What time of the day - Under what condition difference can happen.

temperature

According to Yanna (1994) the availability of solar radiation in the site is by itself dependant on the atmosphere conditions. Cloudiness and cloud coverage is important factor in UK climate variability. Usually availability of the sun during cloudy winter days are too low to contribute to space heating.

The question that will rise is that with characteristics of the UK climate for colder months of the year (graph 5), when the vertical and horizontal radiation is the least, is there any temperature difference inside the space?

30

25

20

15

Dry Bulb-Temperature °C

10

5

0

1 AM

6 AM

Night-Time

12 pm Day-Time

Outside Db-T

Solar-Chimney Top-Measured

Solar -Chimney Top -Simulated

Solar Chimney Bottom-Simulated

Graph 4 Temperature of top and bottom of sun space simulated and fieldwork results together

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18 pm

00 pm Night-Time

Solar-Chimney Bottom- Measured

According to evaluation of the results and weather data, the simulation (graph 5) is showing that the temperature difference in this space is prone to happen in almost one third of the December 6(12 days) and mostly between 12 o clocks to 14 which will continue to exist up 4 hours yet with the reducing trend in last two ones. Furthermore with the sky cloudiness of more than 30 % the temperature difference will stay below 0.21 °.Similar investigation has shown that the temperature difference will mainly happen in autumn and spring with the probability increasing from 12 Days in December to 17 Days in October resulting from the east direction of the sunspace.

.

Dry Bulb-Temperature °C Graph 5: Temperature difference in sun space in one month

6

As a coldest month of the year

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Stack height and flow rate Further investigation needed to be done to check that the 4.4 m height of the space and also the height difference between inlet and

3

outlet are enough for the air flow while the adjacent doors and windows to occupied spaces are open.

Graph 4: Aperture flow rate of the in December

Flow rate through the solar space window which is connected to the occupied space is less than 0.032 m3/s. Therefore it is unlikely that the effect can reach the bedroom or any further spaces. (Graph 6) With purpose of checking the effect of the air through the hot air supplier window and the effect of the sun space on the adjacent occupied room, four different cases has been shaped to test the alterations in temperature of the room in south-west. These cases consist of opening the windows and doors that are connecting these spaces during coldest months of the year.

2

solar space window

1

The results (graph 7) are showing no matter which door or window is to be opened the temperature difference will be less than 0.3 and the best results will be achieved when the door of the target room is closed. Target window, rooms and doors has been illustrated in figure 5-2 in red colour.

Figure 5–2: Perspective view of first floor, target doors and windows are in red

0.035 0.03

Aperture volume flow rate (kg/s)

0.025 0.02 0.015 0.01 0.005 0 Graph 6: Aperture flow

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Another way to see the effect of sun space is to investigate the heating loads in the same scenarios above. Space 2 and 3 in the second floor and space 1 in the first floor. The space is mostly effected is space 2 which is in adjacent to sun space it reduce the heating load of this zone by 65 % following by 26% for space 1 and 1 % for space 2.

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Considering these three spaces without any connection to the sun space has shown 54% increase in heating load of space 2. This pledge that firstly the effect will not go any further form the space 2 and secondly the sunspace role during winter days is mainly acting as a buffer zone.

External Temperature (°C)

All doors and Windows closed

Chimney window open & all the Doors open

solar space window open & Target Doors open

solar space Window Closed & Target Doors Open

15

Dry Bulb-Temperature °C

10

5

0

-5

-10 Graph 7: different scenarios to check the effect of the solar space on the DBT of adjacent room

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Optimizing the solar space From the results that has been inferred three main cases are considered to be tested.

- Changing the orientation of the solar space - Keeping the same orientation and changing the size and position of the space - Changing specification of existing transparent façade as well as changing inlet and outlet height There might be the optimal case which cannot be implemented in retrofitting this building in which the regulations and situation of existing building has to be considered .From the SAP results the set point in all the heating simulations has been considered to be 21 °C to enable comparison between SAP and dynamic thermal simulation.

B A

Different orientation have a different access to the sun thus the amount of solar incident on the surface differs from one orientation to another. In UK latitude a north-facing façade have direct sun access for very short period unlike the south orientation which benefit from the sun in most days of the autumn and winter from sunrise to sunset. East and west are in between they are in view of sun for half a day. The downside about these elevation is that they get more radiation in summer when it is least needed (Yannas, 1996).

First Case

C

The first case that has been considered for solar space is moving it to the south edge of the building where it will have solar access during cold season when it is needed. (Figure 5-3) Figure 5–3 Position of the proposed sun space: 3D view, First floor and ground floor

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Moving this space with same dimension yet different orientation (figure -5-3) will reduce heating load of space A, B and C by 58%, 35%, 23% consecutively. This will not only increase the effect further more than one room but reduce the risk of overheating in the space itself and also in the adjacent spaces because of the orientation.

Second case Making changes to the height and size of the opening of inlet and outlet and also increasing the air temperature difference which will change the inlet flow rate. The area and the height from these three factors are the ones that are manageable from the architectural point of view for temperature difference is more reliable on the climate (Bhatia, 2007).

.

2 1 3

In this case the orientation has been kept the same, east, yet move the space more to the heart of the plan and increase the size of the space and also the height between two inlets has been increase by 10% (figure 5-4). These alterations has effected more rooms with 36 %, 35%, 9% and 11% for room one, two, three and four sequentially

4

1

Figure 5–4 : Position of the proposed sun space: 3D view, First floor and ground floor

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Case three Case three is mainly dealing with existing situation and is more time and cost efficient way of improvement in the sunspace. In this case solar transmittance of the existing window has been increased from 0.2 to 0.8 also the area of the inlet has been enhance from 0.5 m2 to 0.8 m2 .Comparable heating load results has been plotted on graph 7 and the improvements that can be achieved .

2

5

1

3

4

Figure 5–5 : spaces position inside the house

1600

Heating load in Kwh

1400

Existing

1200

proposing

1000 800 600 400 200

0 1

2

3

4

Graph 8: case three effects on different spaces

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5

5.4.2. Insulation By identifying the probability of temperature difference incident, further more exploration has been done to compare sunny and cloudy day differences in the main occupied space the selected room is south-west bedroom. In order to do so, both field work and simulation results has been plot on same graphs yet separately for sunny and cloudy day.

As mentioned before, heating system in the refurbished house were off during the fieldwork. This is not the case with the old version of the house which is a neighbour house. At this point it was interesting to plot the results of both rooms, of both houses from the fieldwork and simulation, on the same Graph. It is important to draw attention to the fact that weather condition for sunny day in this graph is similar to the one of graph 3 so that any effect form the sun chimney can be traced as well.

Before 5PM

After 5PM

ND

.

2

F Plan: Room Location

House 1

X3

House 2

25 Sunny- day

20

Dry Bulb-Temperature °C

15

10

5

Day-Time

Night-Time 1 AM

Night-Time 12 pm

6 AM

18 pm

0 Outside Db-T

Measured DB-T House 1

Measured DB-T House 2

Simulated house 2

Graph 9: House one and two south-west room

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Simulated House 1

00 pm

It has been tried to show these results in this graph:

Moreover, the presence of architect during the construction phase and further explanation from him to the builders effect the quality of details and continuity of the insulation. Consequently the construction gap has been reduced as it can be inferred from the DBT in simulated and fieldwork results and also presence of stability in the graphs. Graph 11 is showing how the changes has effected heating loads of house 1 comparing to house 2 in the first floor room by room.

- The differences between the free running retrofitted versions of the house compared to the older version with the heating on.

- Illustrate the differences between the cloudy and sunny day to investigate the effect of the sun space more.

It can be inferred from graph 4 that house two results are fairly close to house one in spite of the fact that heating system was on in the second one . A considerable gap from simulations and fieldwork results was expected according to literature review. Yet the results for house one is not showing much gap, with less than 0.5 °C in for house one.

There is one more important deduction which is the fact that a room from the first floor of house one shows almost constant trend in both sunny and cloudy days which can put another layer of justification on the performance of insulation.

25 Semi sunny day

20

Dry Bulb-Temperature °C

15

10

5

0 Outside Db-T

Measured DB-T House 1

Measured DB-T House 2

Simulated house 2

Graph 10 :South-west bedroom DBT temperature for 24 hours

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Simulated House 1

Energy consumption in KWh

3000 2500 2000 1500 1000 500 0 South east Room

North east Room

North west Room

South west Room House 1

Staircase

South bathroom

Corridor

Staircase

House 2

Graph 11: Heating loads of each room in first floor comparing House one and house two

Increasing insulation to ground floor level

B

A

According to the occupant’s comments, in sitting area (shown as B in figure 5-5) there is a feeling of overheating. Also space A, an Eastfacing room, window’s size is bigger than it was before. Further investigation has been done to see if overheating is happening in the house one which has shown that both room mentioned above are not passing CIBSE TM52 criteria by incorporating London weather file which consider more hot days during summer time (table 3)

C

This has shaped another idea which was making a model with a continuous insulation going around the whole house and at the same time evaluating whether it will increase the overheating risk or not.

Figure 5–6: position of the overheated rooms in existing and proposed scenario

Occupied time 5PM to 7 AM and weekends

Temperature equal or more than 25 °C 5.5 % of the occupied hours

Table 3: Checking the house against CIBSE TM-52 criteria

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Spaces

Windows

A and B

Fully Open when the temperature is equal or more than 22 °C

Results are showing that space C will not Pass CIBSE TM-52 if the whole house is to be insulated. Additionally to CIBSE TM-52, graph 10 is showing the frequency of increase in DBT in each space of the house in both existing and whole house insulation scenario. According to this graph the probability of the DBT being between 25 °C and 26°C in GF rooms will be more than other domains.

Neighbour house (house two which is the before retrofit version of house one) which has all the characteristics of 1970s house is using 24180 Kwh energy which is 22 % more than what SAP results is proposing for retrofitted version. It can be inferred from comparing each case that the insulation by itself can reduce the energy consumption by 41% followed by using double glazed window contributing around 20 % in energy reduction.

Amongst all these cases, the best case would have been insulating the whole house and changing the position of the solar chimney to the south part of building.

5.4.3. Role of each strategy in reducing heating load The existing house (as it is retrofitted), neighbour house and all cases and scenarios mentioned above will reduce or increase the heating loads. Graph 11 and table 4 has been produced to make the comparison possible between each one of them.

.

Number of the hours

400 350 300 250 200 150 100 50 0

x ≥ 25.0-1st floor insulated

x ≥ 25.0-Whole house insulated

x ≥ 26.0-1st floor insulated

x ≥ 26.0-Whole house insulated

x ≥ 27.0-1st floor insulated

x ≥ 27.0-Whole house insulated

x ≥ 28.0-1st floor insulated

x ≥ 28.0.-Whole house insulated

Graph 12: frequency of temperature in each room comparing existing house with the house being completely insulated

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It has been proven before that by over insulating the house the probability of overheating will be increased. So the best results could have been resulted just by relocating solar space area.

consumption of the building. One of the reasons of the difference between results can be the fact that in reality the cavity walls of the property benefits from injected insulation while in SAP results this has not been considered.

What is more interesting is the fact that dynamic thermal simulation present more promising results than what it has been anticipated for the house through SAP results which is the standard assessment procedure to compare and anticipate the energy

As mentioned before in all simulations related to heating load the set point has been considered to be 21 °C according to SAP calculations and the average infiltration rate for the house is 0.75 ach.

30000 Energy consumption in KWh

25000 20000 15000 10000 5000 0 Typical 4 bedroom detached House

Neighbour SAP Results House

House House With House House as without insulation retrofitted retrofitted insulations just for GF without With High solar space Efficient Window

Graph 13: Heating load in each scenario and cases compared to Existing house 1 and 2

.

Table 4 : The contribution of each case in energy consumption reduction

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House with House case one covered with proposed insulation solar space and location proposed solar space

It is important to mention that the energy bills included some days that the exact readings of meters were not available for the energy company so the estimation has been used.

Furthermore, The house during September to February was still going through minor amendments and also the results were available just for four month, thereby it is expected that the energy consumption will reduce more in the future bills. Graph 5-6 is showing the results of monitored energy bills for four month of the year.

5.5. Energy consumption after the refurbishment As mentioned, phase one of the refurbishment has already completed in September 2018, with the help of the owner of the house the energy bills has been monitored.

From the previous year’s energy bills it has been inferred that 82% of the whole energy consumption has been used from September to February of each year The refurbishment has already reduced 21% of the energy consumption in the house during 4 month period as it has been shown in the energy bills.

year 2017

year 2018

year 2019

2500

Energy consumption in KWh

2000

1500

1000

500

0 September

October

December

Graph 14: energy bills showing amount of energy consumption in 4 cold month of the year

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February

Conclusion Several conclusion can be made from this chapter some of the most important ones has been mentioned below: - Taking the principles into consideration is the first and foremost important initial steps to avoid any complication or overestimation of the role of any passive strategy.

- No matter how small or big the project is, architects should try to provide the most accurate and readable version of drawing to the contractors and builders.

- Calibration is one of the important steps in simulation since it can not only make the result as close as possible to the reality but also make irregularities in the readings more comprehensible.

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6.

Cost analysis

This chapter is an analysis of capital cost of the project per square meter per extra details that the architect has designed.

Also it will include the anticipation that fairly how long it takes that the energy saving from each strategy pay back the initial costs.

This chapter will include:      

Introduction Capital cost analysis Methodology Specification Costing scenarios Conclusion

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fact that environmental measures should be considered as an economical approach or not.

6.1. Introduction While working at small architectural offices it is so hard to convince costumers to implement any environmental friendly strategies, mainly because of their perception about it being expensive.

6.2. Capital cost analysis The dispensation of the cost in each element of construction is called as cost analysis. Cost analysis can induce information that can be used to estimate cost of future building.

Similarly, in the project, it make it possible to compare between the costs of different building aspects enabling to choose most cost efficient ones with the highest performance.

The most frequent question in this regard is how much it will cost to build any extra bits of environmental strategies and how these efforts will reduce the costs in long run.

That was the main reason to add this chapter to the thesis to compare the capital cost of each strategies that has been used in this house.

According to RICS (2013) cost analysis can be used:

Cost has always been a great significance to choose material and construction methods in architecture, therefore finding the best option between all available choices specifically in refurbishment is always combined with financial decisions. Depending on the measure, purposes, quantity and quality of refurbishment it has been always important to find the cost efficient choices.

- Estimating the costs of similar buildings - Estimating the cost of similar construction elements - Comparing the cost of design options at an element level - Cost modelling design solutions.

6.3. Methodology

The approach to the cost analysis in this thesis is slightly different in a way that it has been done through architectural details that has been used in the retrofitted house. It will also consider the comparison between some of proposed cases in chapter 5 to see the initial cost of selected ones compare to benefits that they would have bring in terms of energy consumption.

As a first step sketches and detail drawings has been collected with the help of Scott batty as an architect and owner of this house. The sketches will include the insulated cavity wall system, the roof insulation system, extension’s insulation, sun space and also the double insulated facade of the first floor.

For the aim of this thesis, capital cost analysis has been done for the thermal envelope, floor, roof, wall solar space and windows separately.

Spon (2018) as a UK leading costing manual has been referenced as a manual to calculate the labour work and the time that each of strategies needed to be done. The name of each product was available therefore a direct quote has been requested from the producer.

In practice, the condition of the building before refurbishment is a key factor shaping the capital cost of refurbishment and also the 67

In order to enable the readers to compare the work of architect U-value has been mentioned in comparison with the part-L of the building regulations which provide guidance for building work carried out in England make it clear that how much thermal resistance of each material has been improved compared to general practices.

the roof is 0.15 W/m²K. (Part L regulations suggested 0.18 W/m²K)

Front extension floor Front floor extension is benefiting from almost 0.2m continuous insulation board which is covering the whole floor of extension of the north-east room with the u-value of 0.14 W/m²K. (Part L regulation suggested 0.25 W/m²K)

6.4. Specification External walls

Roof and loft insulation

Cavity walls surrounding the house has a thickness differing from 0.26m to 0.32m it consists of one external brick layer with the cavity in between which has been filled with Polystyrene Bead the inner leaf of the wall is 100mm block work with the u-value of 0.3 W/m²K. (Part L regulations suggested is 0.3 W/m²K).

Roof structure is starting from a layer of vapour control inside with the 0.15m insulation layer covered on top with membrane. Final layers are tiles on the top of two layers of horizontal and vertical battens with the first layer forming an unventilated space.

Windows

Loft is also benefiting from a thick layer of insulation separating the final unheated space of the house from the occupied space. The final U-value of the roof is 0.11 W/m²K. (Part L regulation suggested 0.16 W/m²K)

Windows are double glazed windows filled with argon gas with u value of 1.4 W/m²K and 1.3 W/m²K in case of the sliding glazed doors in back yard extension. (Part L regulations suggested 1.6 W/m²K)

External wall of the first floor with cladding The tea cosy idea has been formed details of this part of the house, which is working like a blanket around the walls of the first floor.

Starting from the outer part of the wall with the layer of insulations covered by the breathable membrane which is under a layer of vertical and horizontal battens forming a structure for the final larch vertical cladding.

The final U-value of the first floor wall is 0.2 W/m²K. (Part L regulation suggested 0.3 W/m²K)

Extension roof For the phase two architect wants to add a sedum roof on top of extension that is the reason why insulation and membrane such as top seal has been consider for the outer layer of the rare extension. Another layer of continuous insulation with 0.12m thickness with vapour control layer at the bottom facing the warm part of the roof. The final U-value of

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Sketches and detail drawings Here is the table of main important details of structure.

Sun space detail

- 120mm kingspam k7 Kooltherm insulating board between new rafters - 150x50 C24 joist - Rhinovent Pro Breathable Membrane - Polythene vapour control layer - Marley Eternit tile 200 fascia depth - Tantalised batten - 38 mm cross batten - Continuous inset aluminium gutter by ARP Aluminium - 150x50 joist around roof light

Tea cosy detail

- Block layer - Injected insulation - Brick work - 50mm rigid Kingsman Kooltherm insulation - Nilvent breathable membrane - 38mm vertical batten - 38mm horizontal batten - 19mm horizontal batten - Larch vertical cladding

Rare extension roof detail

- 100x100 angled welded to top of c section - 300x100 steel PFC - 120mm continuous Kingspam warm roof insulation - Flat roof membrane - Recessed mastic

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Roof and loft detail

- Kingspam k7 kootherm insulation board between rafters - Extra layer of insulation up to 20cm at the bottom of loft space

External ground floor detail

- 10 cm layer of block - Cavity injected by Polystyrene Bead - 10 cm layer of final brickwork

Front extension floor detail

- Continuous larch block - 300X100 Steel C section no - 150X50 c24 joists at 400 - White rendered soffit

Table 5: details of the main important features source: Scott batty s architecture

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6.5. Costing scenarios around 10000 £ difference for a typical four bedroom house.

Costing scenarios has been developed to make comparison between three main types of that is possible to consider for a refurbishment projects. The methodology in each one is similar yet the type of material that has been used to get the quotes are different. First scenario is doing the refurbishment with the similar details yet without extra parts that the architect has been used in the evaluated project. Second one is using the low cost materials and third one is when the main aim is to incorporate high quality components.

If just materials are to be considered the cheapest one will be adding extra layer of insulation in extension with 2.2 £ square meter in front extension and 3.5£ per square meter for front one followed by injectable insulation costing up to 7.5 £ square meter and lastly 20 £ per square meter for loft and roof insulation. Also adding extra layer of insulation around the wall combined by cladding will cost 50£ per square meter.

Amongst all, incorporating sunspace will cost more comparing to rest of details about 280£ per square meter since it has transparent façade.

It is important to mention that labour work is also considered and the time that is needed to construct each square meter of these features. All scenarios will include material, labour and also hours of labour required.

Interestingly, it is possible to incorporate insulation strategies by spending less than 30£ per square meter yet the difference in cost is dependent on the quality.

For windows a typical 4 bedroom house has been considered and the results has been illustrated in different graph separately for the rest of results. As graph 14 is showing the most expensive part of renovation is updating the windows. Between using typical type of double glazed window which can satisfy the regulation to a low-emissivity high efficient double glazed one there will be

Window is the most expensive part on retrofit followed by constructing sun space area, cladding on façade plus insulation and extra layer of insulation in extension and in between cavity wall.

30000 Pounds (£) per square meter

25000

20000 15000 10000 5000 0 Typical Retrofit

Low Quaility

High Quality

Graph 15: Windows cost scenarios

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600 500 400 Pounds (ÂŁ)

300 200 100 0 Solar area

Typical Retrofit

Tea Cosy

Low Quaility

Front Extension

Rare Extension

Whole Roof

Ground Floor Wall

High Quality

Graph 16: Capital cost of each extra part of the refurbishment in each scenarios considering labour work and time

Long term financial benefit

If the inflation rate will be almost the same for same 10 years period after 2024 and the reduction in heating load tend to be 61% as it has been calculated in chapter 5.

According to Statista website inflation rate in UK from 2014 to 2024 fluctuates from 1.46% to 2 %. This will include different products as well as gas and electricity and take taxes and federal fees into account. (Table 6)

The house will save 38880 ÂŁ each 10 years compensating the capital cost of roof insulation in 34 months , windows in 82 months, Tea cosy idea in 89 month and sun space in less than a year. By considering heating loads and capital cost in 36 years time the cost for material and labour will be recompense.

Before retrofit, the annual energy bills of the house one is showing around 19200 Kwh usage of gasper year.

2014 1.46%

2015 0.04%

2016 0.06%

2017 2.68%

2018 2.48%

2019 1.84%

2020 2.01%

2021 2.01%

2022 2.01%

2023 2%

2024 2%

Table 6 : Inflation rate in UK from 2014 to 2024 source: https://www.statista.com/statistics/270384/inflation-rate-in-the-united-kingdom/

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Conclusion Sun space Having done both energy and cost analysis some conclusions can be made.

more while the improvement in energy consumption would have been just 7%.

In order to implement any kind of passive solar energy strategies it is important to consider the site and if the literature and principles are to be referenced they need to be done with the careful consideration of the site and microclimate.

Insulation vs high efficient window In small practices who are usually doing small projects of retrofit and refurbishment the budget is really strict and clients are so hard to be convinced to do any extra work therefore the decision that which step and strategy should be prioritise is important.

In BarnCroft house retrofit if the construction of sun chimney has been done with more careful consideration of better distribution and façade it would have contributed 6 % more in energy reduction and cost 400 £ less in total than existing one (case 2 chapter 5 section 4.1). if any changes are to be made to deal with the existing situation ( case 3 chapter 5 section 4.1 ) it will cost 2030£ in total and the final contribution to energy consumption reduction would be 3.2% more .

Insulation will cost 45% less than using high efficient window yet it can be more effective to reduce energy consumption by 25% compared to windows.7 Careful detailing 19th century was almost the start of architects settling down in the offices and being away from the architectural sites. In Barncroft house presence of architect on site with one to one scale drawing has helped reducing the construction gap (Results from the chapter 4 and 5).

Insulation As mentioned before one of the main element in construction which the building will loss heat from is through roof therefore if the project has a limited financial resource it is important to try to identify the main weak points of building. Moreover over-insulation will not only increase the risk of overheating (section 4.2 chapter 5) but also will not be financially efficient. In Barncroft house if the architect continued the Tea cosy layer up to the ground floor there was a need of 37000£

Getting back on site and try to explain the main purposes of constructions and details to contractor specifically in small scale refurbishment and retrofit where the engineer is not usually present at site will alleviate the construction process and can be considered as an environmental strategy itself.

7

Consider the fact that this is the case when the property is already benefiting from the first or second generation of double glazed windows

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References Articles and Books

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24 June 7 reasons to love living in a 1970s property Ideal Home June 24, 2015 5:47 pm https://ksassets.timeincuk.net/wp/uploads/sites/56/2016/11/ideal-home-author.png https://www.bbc.co.uk/bitesize/guides/zpykxsg/revision/3 https://www.s-cool.co.uk/gcse/geography/weather-and-climate/revise-it/the-climate-of-theunited-kingdom Lambert, T., A WORLD HISTORY ENCYCLOPEDIA. http://www.localhistories.org/stalbans.html Lydia kallipoliti,l.,” From shit to food graham caine’s eco-house in south London”, http://web.b.ebscohost.com.ezproxy.westminster.ac.uk/ehost/pdfviewer/pdfviewer?vid=1&sid=4 332c008-c278-4093-80a5-456c9b83ca97%40pdc-v-sessmgr06 To coincide with the publication of the UK Climate Change Risk Assessment (CCRA) 2012 http://climatelondon.org/wp-content/uploads/2017/11/CCRA-London.pdf https://www.britannica.com/place/London https://www.london.gov.uk/sites/default/files/adapting_to_climate_change.pdf http://www.nmhydro.ca/pdf/tips/Energy%20loss%20through%20windows %20and%20doors.pdf https://www.nia-uk.org https://www.thegreenage.co.uk/how-much-energy-does-my-home-use/ https://www.statista.com/statistics/270384/inflation-rate-in-the-united-kingdom/ https://www.retrofit2050.org.uk/ 79

Historic England, (2017), Vernacular HistoricEngland.org.uk/listing/]

Houses,[accessed

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University of Westminster

course coversheet form CA1

Marylebone campus I confirm that I understand what plagiarism is and have read and understood section on assessment offences in the essential information for students. The work that I have submitted is entirely my own (unless authorised group work). Any work from other authors is duly referenced and acknowledged .STUDENT MUST COMPLETE THIS SECTION ONLY IN FULL CAPITAL Surname

ESMAILZADEHANJANI

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NEGIN

Course

ARCHITECTURE AND ENVIRONMENTAL DESIGN

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ROSA SCHIANO-PHAN

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Second of September 2019 17012

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