Passive House Plus (Sustainable building) issue 30 UK subscriber

INSULATION | AIRTIGHTNESS | BUILDING SCIENCE | VENTILATION | GREEN MATERIALS

S U S TA I N A B L E B U I L D I N G

AIRS & GRACES

Max Fordham’s air-heated passive wonder

MIDSUMMER NIGHTMARE

No bills - just profit

Somerset passive home that pays its way

Counting carbon

The key role of environmental product declarations

Issue 30 £3.95 UK EDITION

Designing to avoid overheating

Air source heat pumps Study shows strong results in retrofits

EDITOR’S LETTER

PA S S I V E H O U S E +

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Publishers

Temple Media Ltd PO Box 9688, Blackrock, Co. Dublin, Ireland t +353 (0)1 210 7513 | t +353 (0)1 210 7512 e info@passivehouseplus.ie www.passivehouseplus.co.uk

Editor

Jeff Colley jeff@passivehouseplus.ie

Deputy Editor

Lenny Antonelli lenny@passivehouseplus.ie

Reporter

John Hearne john@passivehouseplus.ie

Reporter

Kate de Selincourt kate@passivehouseplus.ie

Reporter

John Cradden cradden@passivehouseplus.ie

Reader Reponse / IT

Dudley Colley dudley@passivehouseplus.ie

Accounts

Oisin Hart oisin@passivehouseplus.ie

Art Director

Lauren Colley lauren@passivehouseplus.ie

Design

Aoife O’Hara aoife@evekudesign.com | evekudesign.com

Contributors

Elizabeth Donovan, Aarhus School of Architecture | Claire Jamieson, architect Urszula Kozminska, Aarhus School of Architecture | Marc Ó’Riain, doctor of architecture | Sofie Pelsmakers, Aarhus School of Architecture | Peter Rickaby, energy & sustainability consultant | David W Smith, journalist | Jason Walsh, journalist

Print

EDITOR’S LETTER

editor’s letter “

Things fall apart, the centre cannot hold; mere anarchy is loosed upon the world.”

The words of WB Yeats in the aftermath of World War I have rarely seemed more apposite, or more frequently quoted by commentators vainly hoping that the immortal words will lend their less-than-inspired writings some gravity and heft – rather than throwing their own ordinariness into sharp-relief.

I don’t wish to make the case for anarchy, and like so many people I watch with horror at the rise of nationalism, the polarisation that is eroding the very notion of society such that common ground may not be found, the retreat into romanticised conceptions of a past that never truly existed: a wave of fevered nostalgia for a utopian dream that risks birthing a dystopian nightmare. But often these concerns come from a particular place: a place where the centre does hold, where any changes that do happen are incremental, and resulting from compromise. Politics, by this diktat, is the art of the compromise.

But the natural world doesn’t do compromise. It doesn’t understand our arguments, and it will not reach agreements with us to enable us to change our behaviours at glacial speeds – if that metaphor holds anymore in a rapidly warming world – without disrupting our economies, or causing taxpayers to grumble.

The confluence of rapidly emerging, exponentially-growing environmental crises that will come to characterise this moment in history call not for compromise, but for informed radicalism. Evidence-based radicalism, you might say.

I’ve always been deeply uncomfortable with the baggage that such radicalism implies - it allows you to be pigeonholed as part of an earnest, pious chin-stroking fringe. As abnormal. As eco zealots whose pontificating isn’t relevant to the struggles of the so-called honest, hard-working people that feature so prominently in so much political rhetoric. In part the problem is aesthetic: the notion that

ISSUE 30 by articulating a set of political arguments as a look, a turn-of-phrase, a particular cause, it becomes possible to ‘other’ it. To turn it into an ism, a lifestyle choice, a misguidedly narrow ideology that is defined in contrast to the unnamed mainstream view. The danger is that the desire to avoid being pigeon-holed and marginalised – and to win over people of whatever political persuasion – can easily lead to compromise, to moderating the arguments in order to make them more palatable.

But the evidence is becoming increasingly clear: we need utterly radical action in all areas of life - buildings, energy, transport, agriculture, industry, protection of biodiversity, etc. We simply can’t afford to compromise anymore.

I have to process what that means in my life and in my work. But I have the beginnings of an answer, at least in terms of how we make buildings. It means quantifying impacts. We have the tools via evidence-based sustainable building standards such as passive house to solve the space heating and cooling issue, though we need to consider impacts of climate breakdown on how our buildings will perform – with the prospect of future temperature increases on one hand and possibly the impact of the Gulf Stream shutting down on the other.

But we have massive ground to make up in quantifying embodied energy and carbon, and in quantifying the multiplicity of environmental pressures our buildings place on an environment that is at breaking point.

We do not have all of the answers: buildings are just one part of the change we need to make, albeit a relatively substantial part. But my colleagues and I hope that our readers find some inspiration and utility in the information contained within these pages, and in our archived back issues and online directory – to help deliver the kind of radically green buildings that the world so badly needs.

Regards, The editor

GPS Colour Graphics www.gpscolour.co.uk | +44 (0) 28 9070 2020

Cover

Max Fordham passive house Photo by Tim Crocker

Publisher’s circulation statement: Passive House Plus (UK edition) has a print run of 11,000 copies, posted to architects, clients, contractors & engineers. This includes the members of the Passivhaus Trust, the AECB & the Green Register of Construction Professionals, as well as thousands of key specifiers involved in current & forthcoming sustainable building projects.

Disclaimer: The opinions expressed in Passive House Plus are those of the authors and do not necessarily reflect the views of the publishers.

ABC Certified Average Net Circulation of 10,046 for the period 01/07/17 to 30/06/18.

About

Passive House Plus is an official partner magazine of The Association for Environment Conscious Building, The International Passive House Assocation and The Passivhaus Trust.

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CONTENTS

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CONTENTS COVER STORY

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30

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INTERNATIONAL

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NEWS

18

COMMENT

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CASE STUDIES

This issue features two new buildings built to the passive house standard - an elementary school in Austria and a gorgeously simple house in the Ore Mountains of the Czech Republic.

Bicester business centre achieves passive house landmark, new research suggests passive houses may be less likely to accumulate radon, and analysis of whether procurement systems are stifling natural building materials.

In his latest column on the history of low energy building in the 20th century, Dr Marc Ó Riain looks at the golden age of solar water heating, and Dr Peter Rickaby writes about the four key principles of managing moisture risk in buildings.

COVER STORY: Legendary engineer builds engine-less home — Max Fordham’s passive house

Engineer Max Fordham — together with bere:architects & Bow Tie Construction — has produced a simple and beautiful urban home with no wet heating system that draws on his lifetime of work applying the principles of simplicity, practicality and replicability to the design of building services.

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Site Specific - Somerset passive house adapts to tight plot

The best architecture responds skilfully and sensitively to its surroundings, so when a long and narrow plot beside a busy road became available in the Somerset village of Chew Magna, architect David Hayhow set out to design a passive house, inspired by nearby farm buildings, that would be both private yet filled with light — quite the challenge given the site’s tight restraints.

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Inner Strength - 60s Dublin City scheme a model for retrofit-based regeneration

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Cork retrofit blitzes new build NZEB standard

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The retrofit and extension of a run-down semi in Cork shows just how radically a typical Irish home can be transformed with a skilful retrofit — and why, if your budget is limited, upgrading the building fabric should be your first priority.

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INSIGHT

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Air source heat pumps are rapidly becoming one of the dominant technologies in sustainable building, but how well do they perform in real world conditions, and can they be part of the solution to retrofitting homes? A rare monitoring study on a pioneering retrofit scheme offers encouraging signs.

Quantifying the greenness of construction products: the rise of environmental product declarations

Climate breakdown and global ecological crises mean that our efforts to make buildings sustainable must go far beyond operational energy use – including number crunching and drastically reducing environmental impacts of building materials. John Cradden reports on progress in the uptake of the building blocks of life cycle analysis of buildings: Environmental Product Declarations.

The dramatic conversion of 22 old bedsits on the north side of Dublin City into 11 passive-grade apartments offers an inspiring example of how to retrofit inner city housing while radically improving quality of life for residents.

Superhomes

CONTENTS

The PH+ guide to: overheating

As awareness of the urgency of the climate crisis grows, efforts to kickstart en masse deep energy efficiency interventions are gathering apace. But poorly conceived low energy building efforts can lead to unintended consequences including overheating – a risk that’s bound to grow as the world warms up. Phi Architecture co-founder Claire Jamieson details the risks and offers some solutions on how to create low energy buildings that are comfortable in summer and winter.

MARKETPLACE

Keep up with the latest developments from some of the leading companies in sustainable building, including new product innovations, project updates and more.

Reflections on sustainable Nordic architecture

It’s no coincidence that Nordic countries are some of the most advanced in the world when it comes to low energy design. Frankly in such extreme climates, needs must. Three assistant professors of architecture at Aarhus School of Architecture, Sofie Pelsmakers, Urszula Kozminska & Elizabeth Donovan discuss areas where we can learn from our Nordic neighbours – and where the favour might be returned.

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AUSTRIA

I N T E R N AT I O N A L

INTERNATIONAL Photos: Bruno Klomfar

A SELECTION OF PASSIVE & ECO BUILDS FROM AROUND THE WORLD

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I N T E R N AT I O N A L

AUSTRIA

WANT TO KNOW MORE? The digital version of this magazine includes access to exclusive galleries of architectural drawings.

The digital magazine is available to subscribers on www.passive.ie

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AUSTRIA

I N T E R N AT I O N A L

UNTERDORF ELEMENTARY SCHOOL, HÖCHST, AUSTRIA

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or this new elementary school in Höchst, architects Dietrich Untertrifaller sought to take the Scandinavian concept of a ‘cluster school’ and apply it to western Austria — the essential idea being to design a building that allows for teaching in small groups across flexible spaces and diverse open areas, many of them outdoors. These open layouts are designed to encourage new and alternative forms of teaching and learning, and Dietrich Untertrifaller describe the Unterdorf elementary school as a “radical, uncompromising example” of these principles.

“There are no hierarchies in a one-storey school building; all children have equal access to the outdoor areas and special classes,” says architect Patrick Stremler.

Large areas of glazing allow teachers to easily see pupils as they are learning or playing in different areas, while some of the outdoor areas are also open for locals to use freely, too.

The school was built to the passive house standard from a pre-fabricated timber frame system, and Stremler points out that prefabrication offers a big advantage in the construction of schools, which typically must be completed to strict deadlines — sometimes even over the summer holidays.

Perhaps not surprisingly, the building’s open, community-centred design was informed by an advisory group that included teachers and community representatives.

“This close cooperation was a key factor in the successful implementation of this trendsetting pilot project, which implements a new standard for schools in Austria,” say the architects.

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Environmentally responsible, low cost heating: Vitocal 200/222-A

One of the quietest monobloc units of its kind thanks to Advanced Acoustic Design Heating and cooling with a single appliance thanks to reversible circuit Up to 40% COâ‚‚ and 20% fuel saving compared to a gas condensing boiler Energy efficiency class: A++ / A (Type 221.A04: A+ / A) Internet-enabled with Vitoconnect (accessory) and free ViCare App Easy to operate Vitotronic control unit with plain text and graphic display No minimum distances between indoor and outdoor unit High DHW convenience thanks to 220-l integral DHW cylinder (222-A) For more information please see www.viessmann.co.uk/vitocal222

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I N T E R N AT I O N A L

Photos: Filip Šlapal

CZECH REPUBLIC

HOUSE ON WINDY PEAK, ORE MOUNTAINS, CZECH REPUBLIC

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his gorgeously simple house has been dubbed ‘House on Windy Peak’ by architects Stempel & Tesar, and true to its name, it is located 750 metres up in the Ore Mountains of the northern Czech Republic, not far from the border with Germany.

And how better to protect yourself against the cold, windy winters up here than by living in a passive house? Built from clay blocks that are externally insulated and clad in the dark timber typical of the region, that house’s simple, rational form — a hallmark of Stempel & Tesar’s work — befits the stark mountain setting. It also made it easier to meet the passive house standard, too, by minimising the area from which heat could escape.

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And while the house is sited near a wind farm, the architects report that the superinsulated, airtight structure is excellent at blocking out any noise. Meanwhile, the main elevation facies south from the mountainside, and the living area is lined with large floorto-ceiling windows to make the most of the sweeping views.

The short summer season also inspired the addition of a ‘winter garden’ — a covered terrace in the central part of the southwestern facade that can be accessed from the living and dining rooms. Thanks to a large sliding window, the space can be permanently opened during the warm season, and shut off in winter. “It has become the heart of the house,” say the architects.

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I N T E R N AT I O N A L

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I N T E R N AT I O N A L

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NEWS

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NEWS

Bicester centre is UK’s first nondomestic passive house ‘plus’

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reating 125 modern workspaces, a new £4m cornerstone development is the latest addition to North West Bicester’s pioneering zero-carbon eco town, Elmsbrook.

A first of its kind, Bicester Eco Business Centre combines Cherwell District Council’s zero-carbon objectives with the rigorous passive house standard, to become the first non-domestic building in the UK certified to the ‘passive house plus’ standard.

The new North West Bicester eco-town is a “revolutionary” development of over 6,000 highly sustainable homes, public facilities and infrastructure, with the recently completed Business Centre offering premium office space for the town’s future population and surrounding area.

Designed to meet the changing expectations of office dwellers, coupled with the call to action from the British Council for Offices for a more committed approach to health and wellbeing in the commercial property sector, the new Eco Business Centre focuses on a comfort-optimised internal environment for business tenants.

The new ‘passive house plus’ standard not only radically reduces energy use in the first instance, as per the classic passive house standard, but also requires buildings to generate a minimum amount of renewable energy on site. Besides meeting this

ambitious new standard, the building is also set to achieve a BREEAM excellent rating.

Sensitively designed, the building strikes an important balance as a distinctive gateway building that inspires a professional, cutting-edge aesthetic, without imposing on the surrounding residential zones and other amenities of the local centre.

Internally, spaces have been designed in collaboration with future users to provide a mixed arrangement of flexible hot-desking areas, self-contained offices and dedicated communal areas, all connected by multi-use spaces that promote interaction and are designed to foster community.

The project has been designed

by Architype and delivered by Kier Construction in a tight one-year programme, made possible through lessons learned on growing legacy of passive house performance buildings between the contractor and design team.

Architect Lee Fordham of Architype said: “It is always brilliant to work with a client that prioritises quality and sustainability. This project has been a fantastic opportunity to bring together Architype’s expertise in both building performance and low-carbon design into a commercially viable scheme that could form a precedent for other buildings of this kind in the UK.” • (above) The new Bicester Eco Business Centre.

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Passive houses open to experience summer performance

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rom 28 – 30 June 2019, the mid-year International Passive House Open Days, organised by iPHA and its affiliates, will take place. The mid-year event allows participants to experience the benefits of buildings built to the passive house standard in a different season to the event in November.

The International Passive House Open Days are a great opportunity to learn about passive house and energy efficient building, get in contact with current owners and learn first-hand what it is like to live in a passive house and what the building or retrofitting process was like. Some open houses and buildings will even have professionals on hand with the knowledge and tools to explain the technical details of passive house projects.

As well as all the opportunities to talk and learn about passive house, participants can experience passive buildings – both residential and non-domestic – for themselves, enjoy the comfortable interior temperatures, take a look at the ventilation system, ask questions and consider the possibilities of passive house for their own building projects.

Free to attend, booking is essential Visit the UK Passivhaus Open Days Summer 2019 event page to find out if any projects are open in your area and for further booking details for each scheme. For more information visit: https://bit.ly/2HOSe9u

(above) Passive buildings from around the UK will be open to visit from 28-30 June, including Ecospheric’s pioneering, petrochemical-free Enerphit Plus certified townhouse retrofit project at Zetland Road, Manchester.

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NEWS

Blind & shutter group calls for Part B changes

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he British Blind & Shutter Association (BBSA) has challenged what it described as the defacto banning of shading on tall glass buildings in Part B of the building regulations, and is seeking a judicial review on several points, principally that the regulation is misconceived as it focusses on combustibility rather than flammability.

Part B of the building regulations covers fire safety and was updated following the Grenfell disaster in London.

“The reality though is that England has a ban on glass skyscrapers due to latest changes to Part B of the Building Regulations. The Shard, for example, could no longer be built,” a BBSA statement said. This is because shading is seen as vital to ensure occupant comfort in highly glazed buildings.

Since December 2018, combustible materials on external walls are banned.

Whilst glass and frames are exempt, the government has confirmed that attachments within the façade or affixed to it are not and this includes blinds, PV and other technologies. The regulation applies to buildings over 18 metres tall with any residential component. The statement said: “So quite simply, tall highly glazed buildings with any residential element are no longer possible due to these latest changes. We are not sure where this leaves building designers trying to meet Part L and TM59 [an overheating assessment methodology].”

“Dynamic shading incorporated within the glass façade is a recognised, proven and safe solution to overheating in highly glazed

buildings.”

“The BBSA fully understands and supports the need to prevent flame spread and can confirm that, based on initial testing, our members’ products will not contribute to the problem of flame spread.” Further full-scale testing is currently underway to confirm this, the group said.

Quality shading is seen as essential to prevent overheating and unnecessary energy consumption for air conditioning, particularly as global temperatures rise.

“Banning dynamic shading products, that are crucial enablers of buildings with large areas of glazing by helping to achieve the all-important energy balance of buildings, is not a solution to the climate change problems we all face,” the statement said. •

Passive homes may have lower radon levels — new study

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nitial findings into radon levels in 75 certified passive house buildings in Ireland and the UK shows that there is a 60% reduction when compared against the Irish national average.

The research has also monitored an additional sample of standard and nearly zero energy homes (NZEBs). The study is also examining ten selected comparative case studies located in high-risk areas for radon, a radioactive gas that causes circa 300 lung cancer deaths per year in Ireland – twice the number of road deaths in 2018.

The hypothesis of the study is that homes built and certified to the passive house standard — which have a specific airtightness level coupled with mechanical heat recovery ventilation systems that are specified, installed and commissioned in accordance with quality criteria set out by the Passive House Institute — have lower concentrations of radon due to the presence of consistent, balanced mechanical ventilation.

The initial research findings (120 results to date) have also

uncovered an interesting development in relation to the radon distribution between downstairs and upstairs. While radon concentrations are usually higher on the ground floors of typical dwellings, there is significant variability in this sample. This finding needs to be analysed further before presentation, said lead researcher Barry McCarron of South West College in Enniskillen.

“Indoor air quality and the prevalence of overheating are attracting an increasing amount of research attention across Europe but post occupancy monitoring of indoor radon concentrations is severely underrepresented, especially in Ireland and the UK,” states the report, titled ‘A Pilot study of radon levels in certified passive houses buildings’ and published in the journal Building Services Engineering Research and Technology.

McCarron told Passive House Plus he believes that the balancing of the mechanical heat recovery ventilation (MVHR) to +/- 10 per cent, as required by the passive house standard, is a key determining factor in the reduced radon concentrations. •

A comparison of the radon levels of passive houses and neighbouring homes in high radon areas. Numbers 8 & 9 are in Salthill, Galway – one of the highest radon areas in Ireland.

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NEWS

PA S S I V E H O U S E +

Is procurement stifling natural building materials?

Words by Lenny Antonelli

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s the very nature of the way that construction products are bought and sold limiting the wider proliferation of natural and sustainable materials? While those in the green building sector may be informed about a diverse array of natural and ecological products, many of these have struggled to penetrate the mainstream market, which tends to rely on the same materials over and over again, like concrete and synthetic insulants.

“The uptake of natural insulation products is limited by the current systems of procurement,” says Will Kirkman of leading sustainable building materials supplier Ecomerchant. “There is often a presumption that if an architect or self-builder wants to specify something, that everything is readily available.

But how easy is it really for a specifier to get the products and materials they are looking for?”

Kirkman pointed out that mineral wool, polyurethane rigid board and polystyrene foams make up over 95% of the approximately £900 million annual total of UK insulation sales.

“The very ubiquitous nature of just a few insulation products creates the artificial impression that these are the only ones on the market,” he said. “The big builder’s merchants, for example, usually don’t stock natural insulation materials on the shop floor — so they can appear to be invisible.”

He likened this representation of choice to going into a supermarket and finding only white bread on the bread aisle — perhaps of various different types and from different manufacturers, but just white bread nonethe-

less. “If all you ever saw is white bread, that’s the bread you would buy,” he says.

Kirkman says this is compounded by the fact that building regulations only measure thermal performance, meaning natural materials are often overlooked by specifiers as too expensive because they are compared with plastic insulants on U-value alone.

Cultural mindsets This point is echoed by passive house architect Jae Cotterell, one of the developers of the PH15 build system from Passivhaus Homes. PH15 is a passive house suitable timber-frame system that uses natural insulants like woodfibre and sheep wool insulation.

“Education is an enormous part of it,” Cotterell says. “If you only look at U-value, clearly the woodfibre isn’t going to perform as well as Celotex [for the same thickness].”

But there are a host of other factors that often aren’t considered when insulation is specified — these include embodied energy, carbon sequestration, decrement delay, breathability and so on.

“The negative perhaps of using a system like PH15 is that you have a thicker wall, but the advantage is you have something that addresses building biology as well as building physics.”

Cotterell also believes there is a perception, at least in the mainstream industry, that some of these natural materials carry greater risk, making the industry very slow to move away from the systems and materials they are used to.

One example is the perception that woodfibre insulation might be a fire risk,

because wood is typically seen as a fuel. “Wood fibre is actually incredibly robust under fire,” Cotterell says. “The timber industry have a big job to do to deal with that cultural mindset.”

Clearly, new lines of communication are needed between those specifying building materials and those supplying sustainable alternatives. Kirkman points out that an expert supplier like Ecomerchant, who cover a huge breadth of sustainable building products, is often engaged too late in the procurement process to be able to offer advice on material choice. Typically an architect will have specified a particular product, and the contractor will then approach Ecomerchant looking for it. But if an expert supplier is engaged earlier, Kirkman says, it can offer advice on the best products and systems to use for a particular application.

It points to an issue that Passive House Plus repeatedly hears from those in the sustainable building sector: the need for a much more collaborative approach to procurement in order to deliver high quality, sustainable buildings — as opposed to the traditional approach, which is based purely on price, and which encourages cost-cutting and the worst kind of ‘value engineering’.

Indeed, Passive House Plus frequently hears about the need for designers and contractors to work together collaboratively from the early stages of a project — but perhaps there is a strong argument that expert merchants have a role to play in that process, too. Passive House Plus plans to return to the issue of procurement, and to cover it in more depth, in upcoming issues. •

(above) A passive house in Wivelsfield, East Sussex, built using natural materials by Kithurst Builders, whose walls were built with naturally insulated passive panels (NIPPs) containing 300mm Steico Zell woodfibre insulation, along with a 60mm woodfibre insulation board.

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NEWS

Housing ‘race to the bottom’ bad for climate & quality — energy expert

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he pressure to build large volumes of additional housing in response to the housing crisis is driven by false logic and risks undermining both the quality of new homes and UK carbon targets, according to Richard Tibenham, lecturer in building physics at the University of Lincoln and director of Greenlite Energy Assessors.

“We often hear that we just need to build more houses to make them more affordable, but this represents a misunderstanding of how the market actually operates,” Tibenham said.

He pointed out that the dramatic rise in house prices between 1997 and 2008 was driven not by an increase in demand, but by financial speculation. "When the desires of profit seeking speculators, landlords and developers was met with a willingness by private banks to extend credit, prices rose.”

"When US subprime mortgage holders started to default in 2008, the system crashed. Central banks intervened using low interest rates and quantitative easing programmes in an attempt to stimulate the market. This prevented a far deeper economic crash, but also prevented property prices from correcting, causing the protracted imbalances that we are now observing. Essentially the interests of borrowers were prioritised over the interests of those yet to invest.”

“The younger generation have been shackled with debts through higher student tuition costs. Traditional financial savings

have been disincentivised via prolonged and historically low interest rates. Real salaries have stagnated, whilst at the same time, landlords have leveraged this position through increased rental yields and asset values. This has driven an increasing divide between the young and the old, the haves and the have nots.”

Illogical targets Tibenham added that the current drive to ramp up housebuilding in response to high prices is illogical, as it is monetary policy that is driving these high prices, rather than demand. “The government target is to build 300,000 homes each year between 2019 and 2025, but this far exceeds what is actually needed to house the UK’s growing population and won't necessarily reduce prices. The real issues here are about quality and distribution and less is being done to address these,” he said.

“There are enough houses to go around, they're just not distributed effectively and many are unfit for the demands of the 21st century. England has an estimated 200,000 empty properties, for example, enough to house its homeless population of 277,000.

Building yet more energy inefficient houses suits certain commercial interests, but not the interests of society at large. Many people underestimate just how pivotal monetary policy has been in causing this disfunction in the market. It's not the free market that many believe it to be, reacting to supply and demand

stimuli; it's heavily manipulated via the credit creation of private commercial banks."

He continued: “There was the intention to build homes to zero carbon standards by 2016, but this policy was pulled shortly before its implementation. Apparently, the argument to build volume outweighed the need for quality. Now the government says it will introduce a new future homes standard in 2025, but by this time, 1.8 million more high energy demand homes will have been built if the governments' targets are to be met. Yet again, this pushes problems a few years into the future, rather than tackling them now.”

“Further inefficient and potentially unnecessary housing stock will create an infrastructure time bomb for current and future generations, leaving a legacy of high energy demand, high emissions housing.

This will inevitably require costly modifications or demolition within a short time frame if we are to address carbon reduction targets.

It would be far cheaper to do things right first time round by, for example, building to passive house standards today." •

Researchers develop plant-based foam insulation

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ashington State University researchers have developed an environmentally friendly, plant-based material that they claim works better than polystyrene foam for insulation.

The foam is mostly made from nanocrystals of cellulose, the most abundant plant material on earth. The researchers have also developed an environmentally friendly and simple manufacturing process to make the foam, using water as a solvent.

The work, led by professors Amir Ameli and Xiao Zhang, is published in the journal Carbohydrate Polymers.

While other researchers have created cellulose-based foams, these plant-based versions typically haven’t performed as well as polystyrene. They are not as strong, don’t insulate as well, and degraded at higher temperatures and in humidity.

In their work, the WSU team created a material that is made of about 75% cellulose nanocrystals from wood pulp. They added polyvinyl alcohol, another polymer that bonds with the nanocellulose crystals and

makes the resultant foams more elastic. The material that they created contains a uniform cellular structure, making it a good insulator.

For the first time, the researchers report, the plant-based material surpassed the insulation capabilities of polystyrene foam. It is also very lightweight and can support up to 200 times its weight without changing shape.

It degrades well and burning it doesn’t produce polluting ash.

“We have used an easy method to make high-performance, composite foams based on nanocrystalline cellulose with an excellent combination of thermal insulation capability and mechanical properties,” Professor Ameli said. “Our results demonstrate the potential of renewable materials, such as nanocellulose, for high‑performance thermal insulation materials that can contribute to energy savings, less usage of petroleum-based materials, and reduction of adverse environmental impacts.”

“This is a fundamental demonstration of the potential of nanocrystalline cellulose as an important industrial material,” Professor

Zhang said. “This promising material has many desirable properties, and to be able to transfer these properties to a bulk scale for the first time through this engineered approach is very exciting.”

The researchers are now developing formulations for stronger and more durable materials for practical applications. They are interested in incorporating low‑cost feedstocks to make a commercially viable product and considering how to move from laboratory to a real-world manufacturing scale. • Scientists have a created a high-performance foam insulation made from wood pulp.

ph+ | news | 17

MARC Ó RIAIN

COLUMN

The golden age of solar water heating Renewable energy technologies are often regarded as new and innovative, but in some instances their roots predate the oil age and go back to the start of the industrial revolution. Dr Marc Ó’Riain finds important insights in past failures of early solar thermal systems.

W

e often consider renewable energy technologies to be recent developments, perhaps as old as the first oil crisis in ’73-’74. It might come as very surprising that solar water heating technology was developed as early as 1760 and in widespread usage in California & Florida by 1900, prior to the widespread roll out of electrification.

In 1760, Horace de Saussure developed a solar heater with a rectangular pine insulated glass topped box, capable of heating air to 109C. The clear glass allowed a certain amount of solar radiation to be transmitted through the glass. The solar radiation was then absorbed by materials in the box construction and this ‘heat’ was slowly exchanged with the internal air increasing the overall temperature (Islam et al 2013).

In 1891, Clarence Kemp released the first ‘Climax’ solar water heater in Baltimore.

He placed several water-filled iron elliptical tubes inside the box in series with cold water entering one side and warm water exiting from the other end. Multiple tubes avoided warm and cold-water being in close proximity, thus avoiding adverse heat exchanges. Although the collector heated water to 38.8C the weakness of the design was in its poor resistance to winter frosts and heat loss at night. A third of all homes in Pasadena and California had ‘Climax’ solar water heating by 1897 (Chiaro 2007).

Figure 1. A Diagram of a roof mounted solar hot water system from the mid 1930s, (Adopted from Scott 1976).

William Bailey improved on the Climax with his ‘day and night’ collector in 1909.

By separating the collector from the storage

18 | passivehouseplus.co.uk | issue 30

unit, and insulating the storage tank people could have hot water in the morning (fig 1).

The black painted collector had narrower water-filled pipes which were more efficient at absorbing solar energy aided by a thermosyphon system which required the storage tank to be mounted above the collector, with hot water rising to enter the top of the tank (Butti & Perlin, 1979). By 1920, Bailey had sold over 4,000 ‘day and night’ units and boom years for solar water heating followed in the 1930s.

After WW2 domestic usage of washing machines was on the increase and thereby the demand for domestic hot water.

Electrical boosters were fitted to new and existing installations. From 1938, the unit price of electricity started to fall steadily from 8c/kWh down to 2.5c/kWh by 1973. The cost of electrical water heaters continued to fall in comparison to the cost of a solar installations. As such the dominant builder-developers adopted the cheaper electrical water heaters. Consumer confidence in solar water heating was damaged by leaking tanks, which, due to a corrosive reaction between the copper tubing and the steel tank, over-flowed causing secondary damage to ceilings, furniture and flooring. Owners were faced with the choice of replacing a solar tank or moving to a cheaper electrical or gas hot water heating (Scott 1976).

As time moved on, solar water heater installations continued to rise in cost as the cost of electricity continued to fall.

Even though solar hot water would still have resulted in long term cost savings, the duration of a mortgage, where families were trading up, would result in the savings being passed onto the following owner. The result would be a collapse of confidence and economics for a previously dominant renewable technology in southern latitudes.

This historical precedent provides an interesting parallel for contemporary policy makers. High capital cost low energy conservation strategies like heat pumps, external insulation, heat recovery ventilation systems and triple glazing may still represent a significant barrier to traditional homeowners, who may not recoup the value within their ownership, despite the existence of 30% government grants for some low energy

strategies. Market acceptance of NZEB retrofit today may require the government to implement more targeted policies. Perhaps, there is a need to set a ten-year timeline for the phasing out of all oil and gas fired heating systems. We need to tell the consumer market that non-renewable home heating will increase by 10% per annum for the next ten years. We may need to increase the grant structures to 50% for all the aforementioned energy conservation strategies and we definitely need a 0% top up mortgage via the European Investment Bank if we are to see a significant increase in NZEB retrofit market penetration in the immediate future. n

Figure 2.

Dr Marc Ó Riain is a lecturer at the Department of Architecture at Cork Institute of Technology, one of the founding editors of Iterations design research journal and practice review, a former president of the Institute of Designers in Ireland, and has completed a PhD in low energy building retrofit, realising Ireland’s first commercial NZEB retrofit in 2013.

COLUMN

DR PETER RICKABY

Managing moisture:

why we must learn the four Cs Moisture problems are the Achilles heel of many new builds and retrofits, explains Dr Peter Rickaby – problems that can be exacerbated with poorly-conceived energy efficiency efforts, and which may become more prevalent due to climate breakdown.

W

e usually photograph buildings in the sun – look at any featured project in this magazine. So, I was surprised, on a recent training course, to be shown a picture of a building during heavy rain. The picture showed an abutment of a pitched roof to a wall, and the rain was bouncing of the roof and running in a torrent down the line of the flashing. The point was that buildings must withstand serious and sustained attack from water, and much traditional construction and detailing is attuned to that task. There are ancient skills involved – look at the outside of any medieval cathedral, where every detail of the stonework is designed to throw rainwater off the building and stop it running down the face of the masonry. Those buildings have lasted for eight hundred years, so the

Dublin. In the UK, much work has been done by the Sustainable Traditional Buildings Alliance (STBA), leading to the development of the acclaimed online ‘Guidance Wheel’.

Publication of the seminal BSI ‘White Paper’ Moisture in Buildings: an integrated approach to risk assessment and guidance has led to the establishment of the UK Centre for Moisture in Buildings (UKCMB) and to the forthcoming update of BS 5250 Code of practice for the control of condensation in buildings. UKCMB now offers CPD courses in Understanding and Managing Moisture Risk in Buildings and is working towards qualifications for building moisture safety professionals similar to those already established in Sweden.

At UKCMB and elsewhere, researchers are improving our understanding of building moisture risks and developing the tools to

Buildings must withstand serious and sustained attack from water, and much traditional construction and detailing is attuned to that task. masons clearly knew what they were doing.

It took me nearly ten years working on domestic retrofit projects to realise that retrofit risk management is all about controlling and balancing moisture. Not only keeping the rain out but also dealing with rising damp, plumbing leaks, and the moisture occupants create through respiration, bathing, cooking and laundry. Not only liquid water but also ice and water vapour.

Not only moisture outside the building but also moisture inside the building (in the air) and in the building fabric. Not only moisture itself but the consequences of having too much of it in the wrong places: damage to building fabric and finishes, and mould, with associated risks to health. Even new buildings are at risk: there are reports of mould in new homes – a consequence of airtightness combined with under-ventilation.

The series of Breaking the Mould articles in Construct Ireland (Construct Ireland is the former title of Passive House Plus magazine) set me thinking about these issues. Those articles have led to the current Hygrothermal Risk Assessment module in the Building Performance course at the Technical University of

manage them. The BSI White Paper sets out four key principles of moisture risk management, embedded in a holistic approach covering the planning, design, construction and operation of buildings. We know these principles as ‘the four Cs’: Context The building context includes not only its location, orientation and exposure (to sun, wind and driving rain) but also its construction, historical and cultural significance, its state of repair, its use and its energy efficiency. All these factors are important considerations.

Coherence The coherence principle is about ensuring that the technical, hygrothermal approach to a building is consistent, in design, detailing, construction and use. It distinguishes two fundamentally different approaches to moisture control. A ‘moisture closed’ approach, as found in most new buildings, attempts to exclude moisture from the building fabric, using impermeable materials. A ‘moisture open’ approach,

as found in most traditional buildings, manages the dynamic equilibrium between moisture inside the building, moisture in the building fabric and moisture outside.

A moisture open approach has greater capability to deal with building defects and provides capacity for drying.

Capacity Where there is uncertainty about the moisture performance of a building, capacity should be built into the processes of design, construction and use. Current and future uncertainties include changes of occupancy and the effects of climate change.

For example, ventilation systems should always be capable of providing more than the minimum ventilation rates required by Building Regulations (and demand control can maintain energy efficiency by matching ventilation demand, room-by-room).

Caution The cautionary principle is well known.

There is a lot that we do not yet know about how moisture interacts with buildings, especially with modern moisture loads, materials, construction methods and standards of heating and ventilation. The unknowns, uncertainties and complexities about moisture risks necessitate cautious specification and ongoing watchfulness to mitigate possible problems. Despite contrary economic pressure, buildings should not be over-optimised.

These four principles are part of the legacy of the late Neil May. The more I apply them to building projects the more I am convinced of their effectiveness. With luck, the four Cs will soon be widely applied by building professionals, we will pay more attention to moisture risks, and we will confidently take more photographs of our buildings in the rain. n

Dr Peter Rickaby is an independent energy and sustainability consultant, Chair of the BSI Retrofit Standards Task Group and Principal Research Associate at the UK Centre for Moisture in Buildings at University College London.

ph+ | column | 19

MAX FORDHAM

CASE STUDY

L E GE NDA RY ENG I NEER B U I L D S

E N G I N E - L ESS H O ME M A X F O RD H AM’ S PAS S IVE H O US E

With this stunning, award-winning passive house in Camden, the legendary engineer Max Fordham — together with bere:architects & Bow Tie Construction — has produced a simple and beautiful urban home with no wet heating system that draws on his lifetime of work applying the principles of simplicity, practicality and replicability to the design of building services.

Words by Jason Walsh

WANT TO KNOW MORE? The digital version of this magazine includes access to exclusive galleries of architectural drawings.

The digital magazine is available to subscribers on www.passive.ie

20 20 | passivehouseplus.co.uk | issue 30

CASE STUDY

MAX FORDHAM

£21.66

per month for space heating costs (estimate)

£8.00

per month for hot water (estimate) Building: Infill mews passive house 145 sqm Completed: February 2019 Location: Camden, London Standard: Passive house (certification pending)

H I

1. Use figured dimensions only 2. Do not scale from this drawing 3. All dimensions to be checked on site and the Architect to be informed of any discrepancies before construction commences 4. All references to drawings refer to current revision of that drawing.

5. Structural and services information shown is indicative only.

Refer to consultants' drawings for details and setting out.

6. All work and materials to be in accordance with current applicable statutory legistlation and to comply with all relevant codes of practice and British and European standards

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Rev A B C D E

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Description Stage 4 draft production information Tender Tender revisions Further tender revisions Construction issue. Inc: plaster instead of fair faced concrete, lighting and electrical updates, gridline E moved, under-slab ins changed, Mew wall cladding details, change to 100mm blockwork, changes following FF slab level error, green roof instead of planters to FF terrace, party wall brick thickness and waterproofing changes.

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hat kind of house would one of Europe’s leading heating engineers build? If you are Max Fordham then you build a passive house, but one that also takes into account decades of both practical engineering work and environmental thinking.

Fordham, who founded Max Fordham LLP in 1966, having worked in engineering since 1958, has been described by CIBSE Journal as “Britain’s most influential services engineer” and is one of the earliest advocates of sustainable building design. At school— the educationally experimental Dartington Hall in Devon — Fordham was on track to become an engineer, but says his interest later began to wane.

“I was interested in physics so that I would learn the science behind engineering, and I was in a school that was an arty school. So then when I went to university I was bored by engineers and interested in architects,” he says.

Project:

442cm 6 Camden Mews

Subject:

Ground floor plan (course)

bere:architects

© Bere Architects 2016

54a Newington Green, London, N169PX

Scale:

1 : 50

Creation Date:

09/13/18

Project:

442cm 6 Camden Mews

Subject:

First floor plan (course)

T +44 (0)20 7241 1064 bere@bere.co.uk www.bere.co.uk Project

0442

Disc. Package. Drawing

Stage

REV

A.G20.P00(course) I

bere:architects

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Description Tender revisions Further tender revisions Construction issue. Inc: plaster instead of fair faced concrete, lighting and electrical updates, gridline E moved, under-slab ins changed, Setting out of GF openings in existing brick garden wall Setting out GF doors. Mews wall demolition marked.

Living room shelf removed and sockets and switches moved, Entrance gate updated

© Bere Architects 2016

54a Newington Green, London, N169PX

Scale:

1 : 50

Creation Date:

09/13/18

T +44 (0)20 7241 1064 bere@bere.co.uk www.bere.co.uk Project

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This was because of a step change in architecture at the time, and one of those who Fordham met was Leslie Martin, one of the architects behind the Royal Festival Hall.

“At Cambridge I met the first architect who wasn’t an artist, he was a designer of buildings,” Fordham says of Martin.

Now retired and in his eighties, though still busy, Fordham recently sought to build a new home for himself. Located in Camden Mews in London, the finished house is a three-storey blockwork-built terrace, in-filling between two existing houses. Just before going to print, it picked up two RIBA London Awards, including the sustainability award for 2019.

A certain frugality informs the design: there are no en-suite bathrooms and no heating system, relying instead on heat recovery ventilation. The simplicity of the house’s architecture also reflects Fordham’s own engineering philosophy of keeping things simple and practical. There is also a clear

13/09/2018 11:27:26

Rev D E F

1. Use figured dimensions only 2. Do not scale from this drawing 3. All dimensions to be checked on site and the Architect to be informed of any discrepancies before construction commences 4. All references to drawings refer to current revision of that drawing.

5. Structural and services information shown is indicative only.

Refer to consultants' drawings for details and setting out.

6. All work and materials to be in accordance with current applicable statutory legistlation and to comply with all relevant codes of practice and British and European standards

1. Use figured dimensions only 2. Do not scale from this drawing 3. All dimensions to be checked on site and the Architect to be informed of any discrepancies before construction commences 4. All references to drawings refer to current revision of that drawing.

5. Structural and services information shown is indicative only.

Refer to consultants' drawings for details and setting out.

6. All work and materials to be in accordance with current applicable statutory legistlation and to comply with all relevant codes of practice and British and European standards

Rev C D E F

G

Description Tender revisions Further tender revisions North window revisions for minor material planning ammendment Construction issue. Inc: plaster instead of fair faced concrete, lighting and electrical updates, gridline E moved, under-slab ins changed, Mew wall cladding details, change to 100mm blockwork, changes following FF slab level error, green roof instead of planters to FF terrace, party wall brick thickness and waterproofing changes.

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focus on accessibility: it is possible to live entirely on the ground floor, for example, while cork flooring provides some safety against falls.

Fordham’s house, though not yet certified, is a passive house. This is interesting because Fordham has in the past been seen as a critic of the passive house standard. But he says that coming to the principles that informed his own house followed a logical process.

“David Levitt [the architect] and I combined to design a little block of around 50 flats that we thought would be pretty efficient, but before you know where you are you find yourself designing for a low ventilation rate so that the heat loss is minimised—and the insulation of components is more or less straightforward,” he says.

“But making it airtight is not straightforward and so you are trying to design a building where the ventilation needs to be limited. Then you have to have a mechanical ventilation system with heat recovery.”

ph+ | max fordham case study | 21

MAX FORDHAM

CASE STUDY

Bow Tie Construction built mechanised test versions of the shutters using Lego.

This was the Caspar (City-centre Apartments for Single People at Affordable Rents) development in Leeds for the Joseph Rowntree Housing Trust, finished in 2000, and it was not a happy experience, though for structural reasons rather than anything energy-related.

A report by structural engineers Arup later found that the building — constructed with a prefabricated system from Japan — had a two per cent chance of collapsing in exceptionally high winds, and it was ultimately evacuated and demolished.

But Fordham’s approach of increased airtightness, adding mechanical heat recovery ventilation and attempting to eliminate the need for heating — principles at the very heart of the passive house standard — was vindicated through experience. And despite the structural issues at Caspar, the project did provide data and reported experience from occupants.

22 | passivehouseplus.co.uk | issue 30

“We had three years’ worth of fuel bills in 50 flats, so there was a decent statistical group showing that, basically, the buildings needed no heat,” says Fordham.

“The heat loss from the flats on a freezing, overcast day was 300 watts. But then the electric use for the refrigeration and all the things that electricity does for the industrial revolution, all of those things, communications, cooking, are producing 300 watts.

That’s the electricity bill for the flats. Then when you add to that that people go to sleep at night: two people sleeping for eight hours at night produce another 100 watts.”

“That, I think is a recipe for making housing…that doesn’t need any [space] heating at all. These would help to decarbonise the nation,” he says.

According to Fordham, ventilation—a lack of understanding of it and crude techniques resulting in overventilation—are the source of the worst excesses of the building

industry.

“Ventilation is certainly the big problem in the industry,” he says. “In particular, once you’ve solved the ventilation problem you’ve got a building that doesn’t really need any heating. What’s happening a lot with passive houses we’re seeing built is that people are demanding things like underfloor heating.”

Fordham believes there is a reluctance to challenge the idea that space heating is an essential component of any house.

“I think it’s a conservatism: people are afraid, so passive house is being adopted but people are adding underfloor heating to the brief. That’s the worst kind of heating to have, in a way, because if you have a thermally heavy [passive] building it doesn’t actually need any heating. So, if you don’t need any heating, you’d better not put in a heating system that is difficult to control and slow to control. It may look very luxurious and nice, but you can’t really turn it off. It’s just wasting heat.”

Fordham’s own house, he says, proves the point: with a properly designed and built house, a conventional space heating system is no longer required. He hopes that this becomes more widely understood. “I hope we can get this message out to one-off builders, to councils and to the Barratt Homes of this world,” he says.

Fordham only moved into his own new house in February, so he has not yet experienced a full winter. He is confident, though, that he will not need space heating even in the depths of the season; perhaps just a sweater. (He did use a small 2kW electric heater, however, to heat up the three-bedroom house at the outset, finished, as it was, in winter).

Now, at the time of writing three months later, Fordham is starting to gather information from the house, both in terms of data and his own lived experience.

“I’m just getting some feedback on the energy use. It’s very interesting: the top has the most glass and is getting the heat. It’s very cosy. The ground floor tends to need a little heat so I’ve just written a note that says that we need to increase the internal air flow.

“It’s very exciting getting some real feedback,” he says.

CASE STUDY

Design for life Alex Whitcroft, co-director at bere:architects, says that working with Fordham, there was a clear direction driven by his ideas.

“It was about focussing on this idea of a building metabolism, a balanced system,” he said. “Max is definitely an engineer at heart.”

Fordham’s decision to go with a passive house was not a Damascene conversion so much as his arriving at the logic of the standard through this own thinking, including, crucially, about replicability.

“It’s interesting; one of the most interesting things is that Max is, quite rightly, known to be a critic of passive house. At the same time Max is an environmentalist and an environmental engineer. Like Wolfgang [Feist], he’s very practical about performance and the science,” says Whitcroft.

Fordham has long stressed that the industry should be able to deliver sustainable performance in a way that is simple and replicable. “Although this is a one-off home and although it’s on a very difficult site it is not just a one-off exemplar, it’s replicable, and replicable with building materials

Photography: Tim Crocker

available in the UK,” Whitcroft says of the block-built house.

Bere’s founder and co-director Justin Bere, one of Britain’s leading passive house designers, had known Fordham for some years, after working with him on a project and he sought some advice for his own self-build house.

“I had half-built my own house and in 2002 asked Max about St George’s School Wallasey, featured in Brenda and Robert Vale’s ‘Autonomous House’ book. I was worried about air quality in a draught-free building, and Max told me I needed heat recovery ventilation,” says Justin Bere.

Indeed, Fordham was an admirer of the house Bere built for himself, and their conversations set Bere off on a journey that was to change his practice forever.

“That set me off on the journey that led to passive house. In 2004, a German assistant in the office said, ‘What you’re doing, with HRV and triple glazing and so on, is passive house, have you heard of it?’ I said ‘no’ and went over to a conference in Austria and was amazed by what I saw,” says Bere.

MAX FORDHAM

“I think Max may have been working on Caspar at the time he advised me on HRV for my house. Like Wolfgang Feist, Max was pioneering HRV.” As for Fordham’s own house, Bere says that it makes some important statements—and not in the sense of showy architecture. “It’s a really important project in terms of making architects, non-passive house architects, move forward. They can’t say ‘Max Fordham wouldn’t design a passive house’ anymore.”

“Throughout his career Max has, in his own way, developed his own version of passive house. He was on the same wavelength but didn’t know about it, and in this he brought together what he was doing and what the Passive House Institute was doing, saying: ‘We’re both on the same mission to fight for the planet’.”

Fordham was also happy to influence an idea in Bere’s home. “He loved the technology of the indoor shading blinds.

They work really brilliantly and even my [elderly] mother can use them. I think Max recognised technical and inventive thinking like his own. “Max’s point was that Georgian houses or Victorian houses have windowwall ratios, and shutters that worked quite well, and he felt we should do an interpretation of that.”

With a properly designed and built house, space heating is no longer required.

ph+ | max fordham case study | 23

MAX FORDHAM

CASE STUDY

At Fordham’s home the blinds are automated and, uniquely, insulated. They automatically close at dusk in winter to prevent unwanted heat loss but can also be used to block out solar gain in summer and provide privacy. During construction, the team from builders Bow Tie Construction built mechanised test versions of the shutter motors using Lego. They even considered using Lego motors for the final version, but there were concerns about its durability.

Building the future Site constraints—the mews being very narrow—and the desire to retain a historic street wall dating from 1850 caused practical difficulties during the construction phase, and increased costs.

But the process of building a passive house is always smoothed by having a contractor who understands the concept. Bere and Fordham put the project out to a negotiated tender, which was won by Bow Tie Construction, who specialise in passive house building.

CONSTRUCTION IN PROGRESS

1

2

3

4

5

6

1 The Isoquick insulated raft foundation system helps to eliminate any thermal bridges; 2 50% GGBS in the concrete helped to reduce CO2 emissions in the floor slab; 3 construction of new lightweight concrete block walls just inside the neighbouring party wall; 4 to keep the wall construction thinner at the party wall, Kingspan Kooltherm rigid board was used externally for insulation here; 5 however the walls of the main facades were insulated with Steico I-joists packed with Rockwool Flexi mineral wool insulation and 6 finished externally with a Steico black breathable board, which was then clad externally with Austrian larch.

24 | passivehouseplus.co.uk | issue 30

CASE STUDY

MAX FORDHAM

CONSTRUCTION IN PROGRESS

1

2

3

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8

9

1 Douglas fir joists to underside of roof with Smartply ProPassiv airtight OSB above; 2 construction of internal studwork with pro clima Intello vapour control membrane behind; 3 Schöck thermally broken connectors used to support 2nd floor planters; 4 construction of the Bauder roofing system with 160mm Bauder PIR insulation under a 3mm bitumen layer; 5 installation of the Paul Novus heat recovery ventilation system and 6 rigid insulated Lindab ventilation ductwork; 7 & 8 construction and installation of the innovative window shutters, which are both insulated and automated, and designed to prevent unwanted heat loss on winter nights as well as providing solar shading; 9 Max Fordham looking on while builder Rafael Delimata examines the Lego test motor for the shutters.

Founded in 2012, Bow Tie has always had a focus on green construction but shifted from a primary focus on materials to a primary focus on passive house design over the years.

“Passive house is a still a challenge,” says managing director Rafael Delimata.

“We definitely see a bigger shift in volume of passive houses being sold. Ours have typically been one-offs but it’s very interesting: we’re talking to developers who are interested and trying to educate them.”

The sentiment will no doubt please Fordham. “So [now] we’re looking at volume construction. We’re talking to one gentleman in west London who wants to do a small development and wants to go with passive house due to air quality and noise

reduction.”

Asked what he would like to see change in the industry, Delimata says that practical measures can be taken, such as moving toward more negotiated tenders rather than traditional ones, facilitating a more collaborative approach between architects and builders.

Also, he says, expert builders can lead architects. “Yesterday I spoke to an architect who said to me ‘I don’t want to have to learn all this [in advance]. I want you to show me.”

“One really interesting thing that comes to mind is that we try to specialise in passive house but [some] architects look at the costs and see us as too expensive or unapproachable. We’d like to see more co-operation between builders like us and architects.”

It’s a really important project in terms of making non-passive house architects move forward.

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MAX FORDHAM

CASE STUDY

26 | passivehouseplus.co.uk | issue 30

CASE STUDY

MAX FORDHAM

SELECTED PROJECT DETAILS Client: Max Fordham Architects: bere:architects Passive house consultant: Max Fordham LLP in consultation w/ Passive House Institute Energy rating assessment: Max Fordham LLP M&E engineer: Max Fordham LLP Structural engineer: Price & Myers Main contractor: Bow Tie Construction Insulated automated shutters: Bow Tie Construction External insulation: Rockwool between Steico fins with Steico Black sheathing board Party wall insulation: Kingspan Green Roof: Bauder Windows & doors: Bayer Schreinerei Roof windows: Fakro Airtightness products: pro clima, via Ecological Building Systems Wood fibre insulation: Natural Building Technologies OSB board: Smartply Thermal breaks: Schรถck / Foamglas / Forterra GGBS: Hanson Regen Steico joists: Ecomerchant Building boards: Fermacell Cork flooring: The Cork Flooring Company Air source heat pump & buffer tank: Daikin Solar PV: LG Heat recovery ventilation: Paul, via Green Building Store Ductwork: Lindab Controls system: Loxone External paving: Wienerberger Airtightness tester: Aldas

Read more about this project in detail

ph+ | max fordham case study | 27

MAX FORDHAM

CASE STUDY

The Low-Energy Builder Serving London and the Home Counties www.bowtieconstruction.co.uk

• 24/7 Project & Cost Information Access • PHPP and M&E Consultancy, Design & Build • Modern Methods of Construction Reduce Costs and Shorten Build For all project enquiries please contact Hagop: 07784 316315 hagop@bowtieconstruction.co.uk 28 | passivehouseplus.co.uk | issue 30

CASE STUDY

MAX FORDHAM

IN DETAIL Building type: New 145 sqm infill terrace home Location: Camden Mews, London Completion date: February 2019 Budget: Private Passive house certification: Pending Space heating demand (PHPP): 13.4 kWh/m2/yr Heat load (PHPP): 8 kWh/m2/yr Primary energy demand (PHPP): 105 kWh/m2/yr Primary energy renewable demand (PHPP): 48 kWh/m2/yr Hot water demand (PHPP): 14.5 kWh/m2/yr Heat loss form factor (PHPP): 3.33 Overheating (PHPP): 9% (excludes automated insulated window shutters) Airtightness (n50 at 50 Pascals): 0.38 ACH Energy performance certificate (EPC): B 83 Energy bills: Estimated cost of £22.60 per month for space heating & £8 per month for hot water based on PHPP energy demand calculations & estimated average UK electricity price of 14p per kWh (exclusive of standing charges).

Thermal bridging: Structure entirely within thermal envelope, except for ground piles & 3 columns in the entrance passage, which are thermally isolated with Foamglas Perinsul & a collar of 400mm insulation respectively.

Schöck thermally broken connectors used to support 2nd floor planters. Insulation in warm

roofs continuous with insulated parapets.

Window frames externally over-insulated.

Overall thermal bridging Y-value: 0.27 W/m2K Ground floor: 11mm click-lock floating cork flooring followed beneath by acoustic floor underlay, self-levelling screed, 50% GGBS in-situ concrete, RIW Structureseal clay sheet with taped joints cast into concrete, 400mm Isoquick XPS insulation, 160mm Cordek Cellcore HX void former, 50mm rough GGBS in-situ concrete blinding. U-value: 0.016 W/m2K Walls (typical exterior wall): Austrian larch cladding (angled to shed water) followed inside by 25mm ventilated air gap, 22mm Steico Universal black breathable sheathing board, 260mm Rockwool Flexi mineral wool insulated batts between 240mm x 60mm Steico Wall SW60 I-joists, 100mm lightweight concrete blockwork, pro clima Intello vapour control membrane, 100mm NBT Pavatex Pavaflex wood fibre insulation, 100 x 50mm horizontal timber battens, 12.5mm Fermacell wall board, 1mm plaster skim coat, zero VOC paint. U-value: 0.11 W/m2K Main roof: PV array on mounting system, followed beneath by 80-150mm soil / growing medium seeded with native meadow plants, Terram 1000 geotextile membrane, 40mm Bauder DSE40 reservoir board, Bauder PE separating foil, 5mm Bauder bitumen capping sheet, 3mm Bauder bitumen underlayer, 160mm Bauder PIR insulation, 2.5mm Bauder bitumen vapour barrier, 18mm Structural plywood deck, 12mm Medite SmartPly ProPassiv airtight OSB with all joints taped, 100mm wood fibre insulation between 250x75mm Douglas fir joists, 12.5mm high density Fermacell board. U-value: 0.12 W/m2K First floor green roof: 80-150mm soil / growing medium planted with native meadow plants followed beneath by Terram 1000 geotextile membrane, 40mm Bauder DSE40 reservoir board, 2 x Bauder Versicell 20

drainage board, Bauder PE separating foil, Bauder bitumen capping sheet, Bauder bitumen underlayer, 240mm Bauder PIR insulation, Bauder bitumen vapour barrier, 200mm GGBS insitu reinforced concrete slab, 15mm render and finish plaster.

Windows & external doors: Bayer Ökotherm passive house certified aluminium-clad timber windows. Sealed with Pro Clima Tescon No.1 and Contega tapes.

Overall U-value: 0.63 W/m2K Roof windows: Fakro FTT U8 Thermo passive house certified quadruple glazed skylights. Overall U-value: 0.76 W/m2K Heating system: Electric heater battery in MVHR supply duct for space heating. Daikin Altherma 2-stage air source heat pump with integrated domestic hot water tank, designed to run at about 2pm each day. A two-stage heat pump over the course of a year is more efficient at heating DHW. 2 refrigeration circuits: one goes to the outdoor compressor, one inside. The second circuit takes heat at circa 45C or so and boosts it to 65C. Ventilation: Paul Novus 300 mechanical ventilation with heat recovery system, passive house certified heat recovery 93%. Rigid Lindab ducting throughout.

Water: All fittings with very low-flow restrictors. All roofs have significant restrictors on the outlets to attenuate rainwater.

Electricity: LG solar PV array with total installed capacity of 5.11kW, estimated annual generation of 4024kW. Green materials: All concrete 50% GGBS. All timber FSC with chain of custody & European spruce plywood. All finishes zero VOC. Natural & rapidly renewable materials used wherever possible (woodfibre insulation, timber, etc).

ph+ | max fordham case study | 29

SITE SPECIFIC

CASE STUDY

WANT TO KNOW MORE? The digital version of this magazine includes access to exclusive galleries of architectural drawings.

The digital magazine is available to subscribers on www.passive.ie

£200 profit per year (with renewable feed-in tariff)

30 30 | passivehouseplus.co.uk | issue 30

Building: Detached timber frame passive house Completed: January 2018 Location: Chew Magna, Somerset Budget: £420,000 Standard: Uncertified passive house

CASE STUDY

SITE SPECIFIC

SITE SPE CIFIC S O M E R S E T PA S S I V E H O U S E A DA P TS TO TIG H T P LOT The best architecture responds skilfully and sensitively to its surroundings, so when a long and narrow plot beside a busy road became available in the Somerset village of Chew Magna, architect David Hayhow set out to design a passive house, inspired by nearby farm buildings, that would be both private yet filled with light — quite the challenge given the site’s tight restraints.

Words by David W Smith

ph+ | site specific case study | 31

SITE SPECIFIC

CASE STUDY

F

We took a gamble on being able to build the house we wanted.

32 | passivehouseplus.co.uk | issue 30

or once, estate agents are not exaggerating when they describe the Somerset village of Chew Magna as “well sought after”. Handily placed near Bristol, the ancient city of Bath and the Mendip Hills, house prices here are not for the fainthearted.

Local architect David Hayhow and his wife Rosemarie had lived for years in the village when they decided they wanted to build a passive house. The problem was, as David says, “hens’ teeth are more common” than finding a good location in Chew Magna.

They just don’t turn up. People have to buy land with houses on and knock them down and start again. But most plots cost £750,000 before you even start demolishing. And we’re not in that price league. We know people who took a big risk, buying and hoping to knock the house down, then they couldn’t get planning permission,” he says.

Eight years ago, the couple finally found a desirable site at auction. The existing building had originally been constructed as a garage workshop but was being used as an office by an estate agent. The price was affordable, perhaps because there were still five years left on the lease.

Planning permission had already been granted for a house, but David and Rosemarie wanted to proceed with a different design more suited to meeting the passive house standard. “We took a gamble on being able to build the house we wanted,” says David. The couple left their project in limbo for several years before applying for planning permission, which was granted subject to a few changes. The build took a year after work began in January 2017. An important early decision was taken to re-use the existing strip foundations, which extended two metres under the ground. This was one of the

CASE STUDY

project’s greenest elements as it negated the need for lots of new concrete.

The long and narrow shape of the site had a great influence on the design, which took its inspiration from a nearby cottage and barn that had once been part of a farm. These two-storey structures had gables facing the high street, and steep, pitched roofs. But David’s passive house was rendered, rather than stone clad, and he opted to place slates on the roof as they blended with the black solar panels.

Getting enough light into the Pump House was challenging. David decided not to put many windows on the east and west elevations, which overlooked neighbouring homes. This made it essential to maximise the light coming from the two gable ends.

“One end was facing south, so it was simply a question of putting in lots of glass. But it wasn’t easy to get light into the middle of the building,” says he says. “We managed it by introducing a double-height area of roof glazing, which we dubbed the Wintergarden.

It provides lots of light for both the ground floor and the north-facing study we share on the first floor. It makes it a lovely space to be in even when the skies are grey outside.”

Photography: David Mirzeoff & David Hayhow

The Hayhows have been monitoring heat performance since moving into the house in January 2018. Temperatures are consistently around 19C or 20C, but David says it feels slightly warmer than that. In March last year, during freezing weather, temperatures only dropped below 18C on two mornings before rising above 20C during the day. Two months later, an early heat wave pushed temperatures inside above 25C, principally because of the large glazed area.

David has since found ways to rectify the overheating issue. He has installed two motorised opening lights to the roof windows, and a small opening in the external wall just above the ground floor which, when activated at night, provide cooling ready for the next day. Meanwhile, the south-facing bedroom windows have been fitted with external Venetian blinds inside a fourth layer of glazing, and the sliding doors to the living area are protected by a shade-sail supported on steel posts. David is also planning to add internal shading to the roof glazing.

In the first year the couple used 3,480kWh from their renewable electricity supplier, but with their 6kWP solar photovoltaic array, generated 5,270kWh in the same

SITE SPECIFIC

period. David says he and Rosemarie love the feel of their passive house. “The house is great to live in. Each space has a particular character and offers small delights at every turn. It is full of light and interesting use of materials.”

He continues: “The study has a high sloping ceiling and looks north onto the High Street.

We are aware of the traffic, but it is subdued by the triple glazing. The study is not as gloomy as north-facing rooms usually are as it gets light from the south through the winter garden roof. We’re also aware of the path of the sun as it travels through the day.”

It is full of light and interesting use of materials.

ph+ | site specific case study | 33

SITE SPECIFIC

CASE STUDY

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34 | passivehouseplus.co.uk | issue 30

CASE STUDY

SITE SPECIFIC

CONSTRUCTION IN PROGRESS

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1 Laying of the concrete slab which was installed over 300mm of Dow Floormate XPS insulation; 2 erection of the closed-panel timber frame system; 3 installation of the Internorm windows on the tight site required a crane; 4 I-rafters in the roof which were then filled with 300mm Earthwool insulation; 5 Smartply ProPassiv airtight OSB to the inside of the roof construction, with airtight taping at junctions and joist ends; 6 the outside of the roof build-up with battening over woodfibre insulation; 7 outside this again was the breathable sarking and the mounting system for the solar PV array, with was installed flush with the roof slates; 8 detail at the wall roof junction with Diffutherm woodfibre wall insulation rising up under the eaves to meet the roof insulation; 9 internal service cavity insulated with Rockwool.

SELECTED PROJECT DETAILS Clients: Rosemarie & David Hayhow Architect: David Hayhow Structural engineer: John Filor Consulting Passive house consultant: Alex Duckworth Passive house assessor: Warm Sustainable drainage consultant: Clive Onions Timber frame: All Timber Frames Mechanical & solar PV installations: Green Flare Electrical contractor: AJW Services Airtightness test: Building Analysis & Testing

Wall insulation: Superglass, via All Timber Frames External wall insulation & render: Baumit, via Back to Earth Additional wall insulation: Rockwool, via Earthwise Roof insulation: Knauf Additional roof insulation: Diffutherm, via Back to Earth Floor insulation: Dow Airtightness products: Ecological Building Systems, Back to Earth Windows & doors: Ecohaus Internorm Roof windows: LAMILUX GGBS cement: Dors Building Services

MVHR installation: Earthwise Construction Permeable paving blocks: Stonemarket Sedum roof: Riefa Green Roof Solutions Air source heat pump: Mitsubishi MVHR: Green Building Store Solar PV: LG Clay paint: Mike Wye & Associates Airtight OSB: Smartply Airtight sealing foam: Illbruck Ground slab: Dors Building Services Fit-out contractor: Earthwise Building Services Rainwater harvesting: Rainwater Harvesting Ltd

ph+ | site specific case study | 35

SITE SPECIFIC

CASE STUDY

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36 | passivehouseplus.co.uk | issue 30

CASE STUDY

SITE SPECIFIC

IN DETAIL Building type: Detached 202 sqm timber frame passive house

year received, leaving a net energy profit of £200.

Location: Chew Magna, Somerset

Thermal bridging: Additional external & internal insulation to walls & roof to reduce bridging; insulated fixings for woodfibre EWI; strip foundations w/ lightweight blocks insulated both sides. Guidance taken from ‘Passivhaus-Bauteilkatalog’ & Steico’s ‘Building System Details with Psi values’.

Completion date: January 2018 Budget: £420,000 Passive house certification: Uncertified Space heating demand (PHPP): 11 kWh/m2/yr Heat load (PHPP): 9 W/m2 Primary energy demand (non-renewable, PHPP): 61 kWh/m2/yr Primary energy demand (renewable): 27 kWh/m2/yr Primary energy generated: 39 kWh/m2/yr Heat loss form factor (PHPP): 3.35 Overheating (PHPP): 0% Airtightness (at 50 Pascals): 0.39 ACH Energy performance certificate (EPC): A (95) Measured energy consumption: 3,480 kWh (mains electricity consumed in first year) Energy bills: £421 for electricity in first year (also covers space heating & hot water).

However, renewable feed in tariff of £621 per

Ground floor: Existing strip footings raised by two courses in aircrete blocks w/ 450mm XPS insulation to inside & 650mm outside. 150mm concrete slab on 300mm Dow Floormate XPS insulation, on DPM, on sand binding, on existing slab. U value 0.107 W/m2K Walls: Closed-panel timber frame walls; Baumit render externally followed inside by 60mm Diffutherm woodfibre insulation, breather membrane, 230mm timber studs insulated with glass fibre, 15mm OSB, Diffutherm Udisteam vapour barrier, 50mm Rockwool-insulated services zone, plasterboard. U-value: 0.120 W/m2K Roof: Slates externally followed by battens, breathable sarking, counter battens, 35mm Diffutherm UdiTop woodfibre insulation, I-rafters filled with 300mm Earthwool insulation, 12mm OSB, 50mm Rockwoolinsulated services zone, plasterboard.

U-value: 0.114 W/m2K Windows: Internorm Studio timber/aluminium HF310 triple glazed windows, HS330 lift &

slide door. Typical overall U-value: 0.8 W/m2K Roof windows: LAMILUX PR60 energy save fixed & motorised roof windows. Overall U-value: 0.9 W/m2K Heating system: Mitsubishi Ecodan 4kW air source heat pump w/ thermal store. Supplies domestic hot water & heating to 3 x towel rails & one small radiator in drying cupboard.

Ventilation: Paul Novus 300 mechanical ventilation w/ heat recovery. PHI certified heat recovery efficiency 93%. Purge ventilation by opening roof windows.

Water: Low flow taps and showerheads; rainwater harvested to 3,500L tank for use in WCs and garden. Calculated water use 29 litres per person per day from mains, plus rainwater use.

Electricity: 6kWp PV system on WSW facing roof, flush with the slate roofing. Produced 5,270 kWh in first 12 months.

Green materials: Reused materials existing foundations, timber and steel from existing site. FSC-certified timber throughout plus timber from our own sequoia. Woodfibre insulation, GGBS concrete, clay paints, Fermacell tile board. Riefa planting board made from flour and coir (coconut fibre).

Landscaping: Permeable block paving to the entrance and parking area. Sedum green roof to lobby area & wildflower meadow to bin store roof using Riefa system.

Graph showing temperatures in the living room at Pump House, January & February 2019.

ph+ | site specific case study | 37

INNER STRENGTH

CASE STUDY

€54 per year estimated space heating costs

Building: Deep retrofit of social housing block Location: Arbour Hill, Dublin 7 Completed: April 2019 Budget: €1.7m Standard: Enerphit certified

38 38 | passivehouseplus.co.uk | issue 30

CASE STUDY

INNER STRENGTH

WANT TO KNOW MORE? The digital version of this magazine includes access to exclusive galleries of architectural drawings.

The digital magazine is available to subscribers on www.passive.ie

INNER STRENGTH 60S DUBLIN CITY SCHEME A MODEL F O R R E T R O F I T - B A S E D R E G E N E R AT I O N

The dramatic conversion of 22 old bedsits on the north side of Dublin City into 11 passive-grade apartments offers an inspiring example of how to retrofit inner city housing while radically improving quality of life for residents.

Words by John Hearne

ph+ | inner strength case study | 39

INNER STRENGTH

CASE STUDY

D

ublin City Council’s recent passive refurbishment of the St Bricin’s Park complex in Arbour Hill offers an innovative template for modernising living space for elderly local authority tenants. In addition to a healthy, low cost, low maintenance living space, the development also delivered a community hub which has already begun to breathe new life back into the area.

Cecilia Naughton, Dublin City Council’s architect on the project, explains that when its refurbishment programme began three years ago, the local authority had around 1,500 bedsits right across the city. Known as zero-bed units, they were small – usually no more than 26 square metres – and as they aged, they became progressively less attractive to tenants. Moreover, the more unattractive the location, the more ‘de-tenanted’ they became. So began a vicious cycle of vacancy, dilapidation and social deterioration.

Back in 2008, before the current housing crisis had taken hold, a decision was taken to suspend the refurbishment of bedsits and instead begin amalgamating them into larger one-bedroom units. Fast forward to 2014, and as the housing lists lengthened, the policy of not re-letting these units was rescinded. Instead, city councillors decided to reintroduce these bedsits to the housing stock and refurbish and re-let them according to demand.

It was also agreed that the city council

40 | passivehouseplus.co.uk | issue 30

would proceed with a more limited programme of amalgamations. To date this has focused in general on elderly residents, since it is this demographic that tends to live in bedsits. While providing tenants with more space was the key driver of the programme, it would never be enough simply to knock bedsits together and leave it at that. Low energy retrofitting would form a central part of the process.

James Walsh of Low Energy Design was the passive house consultant on the St Bricin’s Park project. He explains that two of the three blocks that comprise the development had already been retrofitted when he came on board. In line with the 140+ amalgamations (from 270+ units) completed city-wide between 2014 and 2018, these apartments had been upgraded to achieve BERs of between B3 and A3.

“I had discussions with the council to see if they would be interested in exploring Enerphit, which is the passive house refurbishment standard,” says Walsh, “As part of the process, we talked with Tomás O’Leary of the Passive House Academy about the possibility of achieving passive house certification at design stage, and went out to Rochestown Avenue to look at a project completed by Dún Laoghaire-Rathdown County Council.”

This was a social housing apartment block retrofitted to the Enerphit standard two years ago and profiled by Passive House Plus

So began a vicious cycle of vacancy, dilapidation and social deterioration.

CASE STUDY

INNER STRENGTH

1

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4

above Dublin City Council made it a requirement that the contractor undergo passive house training, and the Passive House Academy provided extensive on-site training, including in 1 airtightness taping; 2 heat recovery ventilation systems; 3 external insulation and window installation and; 4 application of liquid airtightness paints.

in 2017.

“As we were achieving such good BERs, our internal client in the council – housing maintenance – encouraged us to see if we could achieve the highest standard available,” says architect Cecilia Naughton.

“Another factor in the decision to aim for Enerphit was the fact that these were elderly tenants, a cohort particularly vulnerable to fuel poverty.”

“We find that a lot of our older tenants simply won’t put the heat on,” she says.

“They’re too worried about being unable to pay the heating bill.”

The project was also part-funded by SEAI’s deep retrofit programme, part of which includes post occupancy monitoring. As tenants only moved in during April 2019, this has only just gotten underway. In all, 22 bedsit apartments were amalgamated into eleven one-bed apartments as part of this phase of the project, undergoing a passive retrofit in the process. In addition, the

Photography: Paul Tierney

community centre which forms part of the complex was also renovated to a very high standard.

But perhaps the most innovative feature of this project lies not so much in how it was refurbished but more in how the construction and design teams engaged with passive principles onsite. For a start, the council made it a requirement that the contractor undergo passive house training. James Walsh explains that a space was prepared in the canteen of the community centre and Tomás O’Leary of the Passive House Academy provided extensive passive house training right through the project.

“It included everyone on the contractor’s side and also a substantial number of council personnel,” says Walsh. “Tomás also brought in people to do demonstrations on things like airtightness and external insulation. He did talks onsite, and participants installed airtightness products on models.”

The training materials were developed as

part of an EU Horizon 2020 project called ‘Fit-to-NZEB’.

“I think the training made all the difference,” says Cecilia Naughton, “If we didn’t have it, it would have been a lot more difficult to achieve what we achieved. If I was doing it again, I wouldn’t change a thing.”

Achieving passive standard airtightness in a retrofit is always a challenge, and St Bricin’s Park was no different. A combination of Blowerproof paint-on airtightness sealant applied at junctions of floors and walls, Siga membranes and tapes at ceiling, and tapes to external windows and doors achieved an average standard of 0.55 air changes per hour (better than the passive house standard of 0.6, never mind the Enerphit standard of 1.0) “You can buy insulation, windows and heat recovery ventilation, but you can’t buy airtightness.” says Tomás O’Leary.

“Achieving these levels of airtightness, especially on retrofit, is all about attitude

ph+ | inner strength case study | 41

INNER STRENGTH

CASE STUDY

CONSTRUCTION IN PROGRESS

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1 The original building after being gutted prior to retrofit and 2 after the construction of new Quinnlite blockwork walls and installation of new Munster Joinery windows; 3 Compacfoam thermal breaks were installed as structural support under windows, with aluminium starter track for the external insulation layer; 4 the new Baumit external wall insulation featured high density expanded polystyrene at ground level with 5 Rockwool insulation above and was 6 principally finished outside with a dry dash finish, with brick slips to some places too.

and aspiration — traits which were found in abundance on this project from start to finish.”

Meanwhile, external insulation was deployed to achieve the requisite U-values on the walls and to eliminate thermal bridges.

To the same end, a large concrete eave to the front of the building had to be cut away and the new eave wrapped in insulation. Retrofitting mechanical heat recovery ventilation ducting also caused headaches onsite.

“Ceiling heights were very restricted,” says James Walsh, “and existing walls also caused problems, so we had to work with confined spaces while at the same time trying to keep duct lengths as short as possible. We worked closely with Maurice Falvey in Nilan to come up with solutions.”

The newly upgraded apartments meet current space standards, have vastly

42 | passivehouseplus.co.uk | issue 30

improved thermal performance – up to 80% better than the previous units – and are fully compliant with the current building regulations. It’s interesting to note that because the apartments will remain in the ownership of the council in the years ahead, one eye is kept on long-term maintenance issues.

“Everything has to be accessible and replaceable,” says Cecilia Naughton. “There are insulations for example that have to be replaced every fifteen years. We need to be able to get at those. And that too is why we surface-mount everything. This may not give us the best look but it’s very practical. If you have to rewire, you just remove the existing wires and put in new ones.”

There are many reasons why a passive house environment is particularly well suited to elderly occupants. Costs are low, maintenance is low and of course you’ve

also got the health benefits associated with living draft-free in clean air. There are however what Naughton characterises as ‘generational’ issues.

Each of the St Bricin’s Park apartments is equipped with a Nilan Compact P exhaust air heat pump, which provides space and water heating, and ventilation. During the handover process last month, one of the queries that kept coming up centred on gas bills.

“You had to explain that they have a heat pump, and that it heats air and water, and because the building is energy efficient, you should always have a comfortable temperature with permanent ventilation... And they say yes, but when do I get my gas bill?”

The idea that the source of heat is always on is very difficult to accept if you’ve always understood that the more heat you use, the more you pay.

While the council has already invested resources in acclimatising the tenants to their new homes, it was decided to meet with them again in a group once they are settled, in order to address any issues and ensure that everyone understands how everything works.

Looking at future council refurbishments, Naughton says that at a time when additional housing capacity is desperately needed in the city, amalgamations only reduce that capacity. This is not however an argument for keeping tenants in cramped, cold living conditions. The solution, she believes, is to do as Dun Laoghaire-Rathdown County Council did at Rochestown Avenue and add a new floor on top of existing buildings.

Asked if Enerphit offers a credible model for future renovations, she’s unequivocal.

“I think we’ll have no choice really. The building regs are changing and moving towards passive, maybe not in name, but certainly in reality.”

She’s also keen to point out that the completed, fully occupied renovation has gone a long way towards regenerating the whole area at St Bricin’s Park. Two of the three blocks were renovated in an earlier phase of the project, while the refurbished community centre has already begun to provide a focal point for both the tenants and the wider community.

The project was Enerphit certified by MosArt on 1 May, with a space heating demand of 21 kWh per square metre per

In all, 22 bedsit apartments were amalgamated into eleven one-bed apartments.

CASE STUDY

INNER STRENGTH

Lord Mayor of Dublin Nial Ring (left) with Dublin City Architect Ali Grehan (centre) and Tomás O’Leary (right) of the Passive House Academy

CONSTRUCTION IN PROGRESS

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Airtightness detailing including 1 application of Blowerproof liquid airtight sealant around wall-to-wall and wall-to-floor junctions; 2 Blowerproof and Siga membrane and tapes around a wall-to-roof junction; 3 Siga membrane and tapes to ceiling; 4 Metac mineral wool was used to insulate the roof, with insulation brought out into the eaves to meet the external insulation layer; 5 ventilation ductwork coming through the external insulation layer; 6 the heat recovery ventilation systems were installed against existing surfaces and boxed off to make both installation & future access easier.

year, comfortably below the threshold of 25.

Dublin City Council also shared with Passive House Plus a letter of thanks received from a tenant living in one of the previously renovated blocks at St Bricin’s Park. Naughton was particularly appreciative of the letter since the reality is that you usually only tend to hear from tenants when things go wrong.

The tenant wrote: “This is my dream home, my piece of heaven on earth. Every morning, I wake up I still think I am dreaming to have such an unbelievable home. It has brought and still is giving me peace, happiness, security and wellbeing.” You can’t really ask for much more than that.

ph+ | inner strength case study | 43

INNER STRENGTH

CASE STUDY

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www.munsterjoinery.co.uk WINDOWS & DOORS 44 | passivehouseplus.co.uk | issue 30

CASE STUDY

INNER STRENGTH

SELECTED PROJECT DETAILS Client: Dublin City Council Architect (planning): Dublin City Council, City Architects Division Architect (post planning): Low Energy Design & Kelliher Miller Architects Passive house design: Low Energy Design Passive house certifier: Passive House Academy Electrical engineer: Dublin City Council Civil & structural engineering: Dublin City Council Clerk of works: Dublin City Council Mechanical engineer: Morley Walsh & Associates Main contractor: Westside Civil Engineering Quantity surveyors: Dublin City Council Mechanical contractor: CTS Projects Ltd Electrical contractor: Design Electrical Solutions Airtightness tester: Greenbuild EWI & airtightness installer: Ecofix External insulation system: Baumit Aerated concrete blocks: Quinn Building Products Thermal breaks: Compacfoam, via Partel Insulated roofing system: Moy Materials Mineral wool roof insulation: Isover Stone wool external insulation: Rockwool Floor insulation system: Enviroform Solutions / Kingspan Airtightness tapes & membranes: Siga Liquid airtight sealant: Blowerproof Ireland Windows & doors: Munster Joinery Brick slips: Ibstock Heating & ventilation: Nilan Ireland Screed: Smet Building Products

above Drawing of the wall-to-the floor junction, with the broken red line marking the airtightness layer

Read more about this project in detail

ph+ | inner strength case study | 45

INNER STRENGTH

CASE STUDY

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CASE STUDY

INNER STRENGTH

IN DETAIL Building type: 22 x 1960s bedsits (approx.

26 sqm each) turned into 11 one-bedroom (approx 60 sqm each) apartments & a community centre. Concrete block/brick structure with pitched roof & concrete tiles.

Location: St Bricin’s Park, Block 2, Arbour Hill, Dublin 7 Completion date: April 2019 Budget: €1.7m Passive house certification: Enerphit certified Note figures below are averages for the 11 units BER Before: E2 (359 kWh/m2/yr) After: A3 (63.8 kWh/m2/yr) Space heating demand (PHPP, after): 22 kWh/m2/yr Heat load (PHPP, after): 11 W/m2 Primary energy demand (PHPP, after): 127 kWh/m2/yr Heat loss form factor (PHPP): 2.9 Overheating (PHPP): 0% Energy costs: €54/yr calculated annual space heating costs & €203 annual calculated domestic hot water costs, based on mid-range tariff of 18c from Bonkers.ie.

Figures are inclusive of VAT. AIRTIGHTNESS (after, average figures @ 50 Pascals) n50: 0.55 air changes per hour q50: 0.4 m3/hr/m2 GROUND FLOOR Before: Uninsulated concrete floor

U-value: 0.73 W/m2K After: Existing concrete floor with 20mm Smet floor screed, followed below by 62mm Enviroform E-Therm Slim panels including 2 x 6mm ship lapped mineral boards & 50mm Kingspan PIR floor insulation. Some deeper sections have an additional layer of 50mm QuinnTherm PIR floor insulation.

U-value ranges from 0.18-0.23 W/m2K WALLS Before: Concrete and brick cavity block walls.

U-value:1.78 W/m2K After, front & rear walls: 12.5mm plasterboard on 15mm dabs internally, followed outside by plastered 215mm Quinnlite B7 Blockwork, externally insulated using Baumit external wall insulation system comprising 200mm Rockwool dual density slab and dry dash finish; some sections with 180mm Rockwool dual density slab and 20mm Ibstock brick slip finish.

U-values: 0.14-0.15 W/m2K After, gable walls: 12.5mm plasterboard internally on 10mm dabs, followed outside by plastered existing 60mm cavity wall with brick outer leaf with 60mm of Kore Diamond BASF 5200 cavity wall insulation, externally insulated using Baumit external wall insulation system comprising 150mm Rockwool dual density slab and 20mm Ibstock brick slip finish. U-value: 0.16 W/m2K ROOF Before: 50-100mm mineral wool insulation.

Roof tiles to sloped areas, torch on felt and asphalt to flat roof and deck areas externally.

U-value: 0.4 & 2.3 W/m2K respectively After (pitched roof): 12.5mm plasterboard ceilings with airtightness membrane and 400mm of Isover Metac above, between and cross laid over existing ceiling joists. Cold roof space above. U-value: 0.09 W/m2K After (flat section): Paralon roofing

membrane followed below by 140-180mm tapered Paratorch composite insulation, concrete roof, plasterboard and skim finish.

U-value: 0.16 W/m2K WINDOWS & DOORS Before: Double glazed PVC windows and doors. Overall approximate U-value: 2.7 – 4.8 W/m2K After: Munster Joinery triple glazed Future Proof PassiV timber aluclad windows and doors. Overall U-value of 0.80 W/m2K HEATING SYSTEM Before: 20-year-old gas boiler & radiators.

After: Nilan Compact P exhaust air heat pump w/ heat recovery ventilation distributing heat through ventilation ducting. Plus, three small electric radiators in each apartment, controlled by the Nilan unit.

VENTILATION Before: No ventilation system. Reliant on infiltration, chimney and opening of windows for air changes.

After: Nilan Compact P — Passive House Institute certified to have heat recovery rate of 75%.

Drawing show continuity of insulation at the wall-roof junction

ph+ | inner strength case study | 47

CORK RETROFIT

CASE STUDY

48 48 | passivehouseplus.co.uk | issue 30

CASE STUDY

CORK RETROFIT

WANT TO KNOW MORE?

CORK RETROFIT

The digital version of this magazine includes access to exclusive galleries of architectural drawings.

The digital magazine is available to subscribers on www.passive.ie

B L I T Z E S N E W B U I L D N Z E B S TA N D A R D The retrofit and extension of a run-down semi in Cork shows just how radically a typical Irish home can be transformed with a skilful retrofit — and why, if your budget is limited, upgrading the building fabric should be your first priority.

Words by John Cradden

€40 per month gas bill

Completed: February 2018 Budget: €280,000 Standard: Nearly zero energy building (NZEB)

ph+ | cork retrofit case study | 49

CORK RETROFIT

CASE STUDY

I

f you’re a passive house advocate in a position to do a deep retrofit but your budget is tight enough that you might have to make some fundamental compromises, what should they be?

Such compromises might come down to spending less on the heating system and other technological solutions and more on the fabric of your home – or vice versa.

Architect Loic Dehaye knew exactly what his priorities were when he finally got the keys to a three-bed semi in Ballinlough, on the southside of Cork city.

He’d had his eye on this 1930s-built house for two years and even missed an opportunity to buy it at one stage, but with a sale having fallen through no less than three times, he managed to snap it up on his second attempt.

It’s easy to see why he persevered. Its location, mere minutes away from both schools and work, would limit the family’s daily commuting times and help to reduce CO2 emissions. Its south-facing rear aspect, suitable for large sections of glazing, would ensure a bright open-plan living space that could open out to the garden and maximize solar gain.

And being a semi-detached house, enough space was available to extend out sideways yet still retain side access for bins and bikes etc.

“I knew it had great potential,” says Dehaye.

“It also was derelict, giving me a good opportunity to go for a deep retrofit.”

As well as a deep retrofit, the €280,000 budget incorporated the building of a two-storey side and rear extension that would make the house into a four-bed with an open-plan kitchen and

50 | passivehouseplus.co.uk | issue 30

living area, a guest toilet, a storage room, a utility room and a converted attic space/play room.

These two goals — retrofit and extend — were so closely intermeshed that Dehaye admits not being able to separate out what proportion of the budget went on the retrofit and what was eaten up by the extension. But having worked on several Enerphit projects for clients over the past number of years, a fabric-first approach to the whole project seemed appropriate.

“We decided to put the capital into the building structure by having all the elements and construction details to passive standard, and keep the mechanical to a simple, cost-effective, well-proven and low maintenance system,” he says.

Specifically, he opted for a condensing gas boiler (to an existing gas supply connection), a solar thermal hot water system, solar PV panels and an Aereco demand control ventilation system.

Although Dehaye is mindful of the environmental impact of opting for a fossil-fuel burning set-up, the system has been designed to be able to switch to a heat pump in future when budget allows.

Indeed, the decision to hold off on investing in a heat pump was made easier by some modelling Dehaye did with the DEAP software to compare the carbon emissions of an air-towater system with the gas boiler and solar thermal, which found that the emissions were similar given the extent to which electricity production in Ireland still relies on fossil fuels.

“It means electricity production needs to

CASE STUDY

CORK RETROFIT

The finished result is beautiful, inside and out..

ph+ | cork retrofit case study | 51

CORK RETROFIT

CASE STUDY

THE EVOLUTION OF CONTROL NEW HEAT RECOVERY VENTILATION

BY AERECO www.aereco.co.uk 52 | passivehouseplus.co.uk | issue 30

CASE STUDY

CORK RETROFIT

CONSTRUCTION IN PROGRESS

Achieving airtightness in the existing structure was a challenge.

1

2

3

4

5

6

1 Architect Loic Dehaye had his eye on this 1930s-built house for two years and even missed an opportunity to buy it at one stage, but managed to snap it up on his second attempt; 2 & 3 as well as a deep retrofit, the €280,000 budget incorporated the building of a two-storey side and rear extension, a steel and timber frame structure built on site; 4 airtightness taping and membrane at joist ends; 5 the new timber frame walls were pump-filled with cellulose insulation from Cork manufacturer Ecocel through holes in the internal OSB layer; 6 thermally efficient, lightweight & insulated window sill from Youghal-based Passive Sills, certified by the Passive House Institute.

SELECTED PROJECT DETAILS Client: Loic Dehaye Architect: Loic Dehaye Architects Civil & structural engineers: EIRENG Consulting Engineers Main contractor: Garry McCarthy Mechanical contractor: Trevor O’Mahony Heating & Plumbing Electrical contractor: CMI Electrical Airtightness tester: Clean Energy Ireland Cellulose insulation: Ecocel Wood fibre insulation: Gutex, via Ecological Building Systems Insulated window sills: Passive Sills

Thermal blocks: Foamglas / Quinn Building Products Roof & wall insulation: Isover Additional roof insulation: Kingspan Floor insulation: Kore Airtightness products: Siga, Gerband Windows & doors: Viking, via West Building Products Roof slates: Tegral Solar thermal system: Kingspan Demand controlled ventilation: Aereco Solar PV supply: Garo Solar PV installer: Paul Sweeney Electrical

continue to be cleaner and self-produced where possible to maximise the benefit of a heat pump,” he says.

So, the bulk of the budget went towards the fabric, including external insulation over the concrete blocks of the original dwelling, while the extension is a steel and timber frame structure built on site and insulated with cellulose insulation from Cork manufacturer Ecocel. Irish-sourced larch timber cladding was used for the front, and triple glazed alu-clad windows were fitted all round, with openable rooflights over the landing and kitchen.

Achieving airtightness in the existing structure was a challenge, however. “We were targeting one air change per hour but could not achieve it. For budget reasons and sustainability, we tried to keep as much partition and structure in place, which made it harder. We did achieve 1.9, which is very good for an existing structure but not enough to qualify the house for Enerphit.”

Dehaye also says that the installation of an Isover metal-stud acoustic insulation system to the party wall has been a big success. “We completely forget we are living next to a family with three young kids in a semi-detached house,” he says.

The finished result is beautiful, inside and out, but the idea of delaying investment in heat pump technology might give some pause for thought. Indeed, this choice is not unlike the ones being made by many motorists interested in buying a new electric car but who have chosen to hold off until battery technology and ranges improve (and prices fall), and until further progress is made in greening electricity generation. This is especially true when considering the carbon intensity of grid electricity has dropped by over a third since 2010, that considerable further drops are inevitable within the lifespan of heat pumps installed today, and the potential of using heat pumps to help mop up wind energy generation at times when demand is otherwise low.

But as Dehaye puts it, the enhanced fabric in this now NZEB-compliant dwelling is there now for the next 40 or 50 years, while the heating system will have a likely lifespan of 15 years or so.

Read more about this project in detail

ph+ | cork retrofit case study | 53

CORK RETROFIT

CASE STUDY

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54 | passivehouseplus.co.uk | issue 30

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CASE STUDY

CORK RETROFIT

IN DETAIL Building type: Deep retrofit to 95 sqm semi-detached house from 1938, plus two-storey side and rear extension & attic conversion. Finished floor area: 197.65 sqm Location: Ballinlough, Cork Completion date: February 2018 Budget: €280,000 (all works excluding fittings) BER Before: E2 (381.62 kWh/m2/yr) After: A2 BER (40.72 kWh/m2/yr) Energy performance co-efficient (EPC): 0.293 Carbon performance co-efficient (CPC): 0.241 MEASURED ENERGY CONSUMPTION (gas + electricity): Before: 381 kWh/m2/yr (estimate) After: 43.14 kWh/m2/yr (Feb 2018 to Feb 2019) Energy bills (after): €532 on electricity incl. all charges & vat Feb 2018 to Feb 2019. €485 gas bill, incl. all charges & vat, in same period.

Gas bill includes non-solar portion of hot water generation. Total: €1,058 Thermal bridging: Quinnlite blocks at base of extension walls, Foamglas blocks to all window & door thresholds, insulated window sill on external wall insulation system.

Airtightness (after, at 50 Pascals): 1.9 air changes per hour GROUND FLOOR Before: Uninsulated concrete floor

After: 150mm Concrete slab with 250mm silver EPS insulation. Polished concrete finish to some parts. U-value: 0.1 W/m2K WALLS (ORIGINAL) Before: Concrete block-on-flat walls.

After: 150mm Platinum EPS insulation and silicone-based render finish externally to existing walls, 32.5mm insulated drylining internally. U-value: 0.15 W/m2K Extension walls: Stick-built timber frame walls. External cladding (Knauf Aquapanel, Thrutone slate or Irish larch) followed inside by battens, breathable rain screen, 22mm Gutex wood fibre board, 200mm studs filled with cellulose insulation, 11mm OSB, 50mm Metac insulation to service cavity, vapour membrane & plasterboard. U-value: 0.15 W/m2K. ROOF (ORIGINAL) Before: Existing roof insulated on flat with 100mm mineral wool.

After: Side attic insulated with 350-400mm cellulose on the flat. U-value: 0.11 W/m2K. Attic room insulated with 100mm Metac between rafters, with airtight membrane & 90mm Kingspan insulated board beneath.

U-value: 0.14 W/m2K Side extension roof: Tegral fibre cement slates on battens/counter battens, followed underneath by breathable roofing underlay, 350-400mm cellulose insulation.

U-value: 0.11 W/m2K Rear extension flat roof: PVC roof followed beneath by 18mm Smartply OSB, ventilated battening, breathable roof membrane, counter joists, joists insulated with 300mm cellulose, airtight membrane, battened service cavity, plasterboard. U-value: 0.14W/m2K

WINDOWS & DOORS Before: Double glazed aluminium windows.

New triple glazed windows: Viking passive certified timber-aluclad windows & doors.

Average U-value of 0.82 W/m2K Roof windows: Flushglaze triple glazed flat roof window to sitting room. Overall U-value: 0.8W/m2K. Velux modular skylight system (2 x fixed & 1 x motorized) to kitchen. U-value: 1.20W/m2K. 3 x further motorized Velux thermally broken triple glazed roof windows to 1st floor landing, 1st floor bathroom & attic space. U-value: 1.20 W/m2K. HEATING SYSTEM Before: 20-year-old gas boiler & radiators; open fireplace.

After: Logic System s30ie gas boiler. 4 heating zones with time & temperature control, radiators with thermostatic valves. Solid fuel Termofoc C-130 stove. Kingspan Thermomax HP400 solar thermal system + 300 litre dual coil Telford Tempest solar cylinder. Hot water produced by solar thermal + gas.

VENTILATION Before: No ventilation system. Reliant on infiltration, chimney and opening of windows for air changes.

After: Aereco demand controlled central acoustic fan for up to six wet rooms. 250m3/h.

Passive stack ventilation via motorised roof windows.

Green materials: Cellulose insulation, timber frame extension, Irish larch cladding. 100% wool carpet, Irish limestone for patio finish. As much of the existing structure as possible retained.

Electricity: 7 x solar photovoltaic panels. Avg. annual output of 1.6kW.

ph+ | cork retrofit case study | 55

SUPERHOMES

INSIGHT

EVIDE NCE BASE :

HOW AIR SOURCE HEAT PUMPS FARE IN CANNY RETROFITS Air source heat pumps are rapidly becoming one of the dominant technologies in sustainable building, but how well do they perform in real world conditions? Can they be part of the solution to retrofitting homes, given the challenges in making existing homes suitable for low energy heating?

A rare monitoring study on a pioneering retrofit scheme offers encouraging signs.

Words by Jeff Colley

A

s the electricity grid continues to decarbonise, the environmental benefits of electrifying heating keep on improving, a process that’s bound to continue in the coming years. Add in the prospect of heat pumps multiplying each kilowatt of electricity into three or more kilowatts of heat and the argument can become compelling.

Analysis by Passive House Plus indicates that the majority of new homes built in Ireland last year are heated via air source heat pumps (ASHPs), which help meet both the energy efficiency and renewable energy targets set out in Part L of the building regulations. But this technology – which is rapidly moving from the margins to centre stage in the UK and

56 | passivehouseplus.co.uk | issue 30

Ireland – is still comparatively new in these markets, at least in terms of en masse roll out, meaning many people still have doubts about their real world performance.

These doubts are most pronounced in the case of retrofitting heat pumps, and the reason isn’t hard to establish: the efficiency of a heat pump is better when the delta T – the distance in temperature between two measuring points – is lower. That ideally means trickling low temperature heat into a large surface area distribution medium such as an underfloor heating system, and into a building which has thermally efficient building fabric, and is therefore comparatively warm to begin with, and slow to lose heat. Existing buildings tend to be far from this scenario, with building

fabric that’s quick to lose heat, and boilers set up to blast heat in at high temperatures into radiators.

Tipperary Energy Agency CEO Paul Kenny and his colleagues had a vision for a different approach. In 2015 the agency launched SuperHomes, a grant-funded retrofit scheme set up with the ambition of delivering cost-effective deep retrofits with a specific, tightly-defined approach: fabric heat loss is reduced by airtightening (to a q50 of less than 5) and insulating homes, while ventilation heat loss is reduced without compromising indoor air quality via demand controlled mechanical extract ventilation systems. By reducing heat losses, an ASHP could be run at relatively low temperatures via the home’s existing heating

INSIGHT

SUPERHOMES

Before and after primary energy scores from BERs for homes which have received energy upgrades under the SuperHomes scheme.

system – in some instances with additional radiators added to increase the surface area of heat emitters. Crucially, the retrofit measures – including heating system changes – would be designed by sufficiently qualified engineers, with well-trained and supported installers, professionally managed contracts, finance and compliance checks. The works were done by a group of dedicated installers: Sola, Leetherm, Churchfield, House2Home and Waterford Insulation.

Costs were kept impressively low: participating households in year one made a net spend of €18,000, after 35% of the costs had been covered by a SuperHomes grant Lack of post occupancy data is arguably the greatest failing in attempts at low energy building, an informational vacuum that creates uncertainty about whether a given energy saving attempt is working or not, which therefore undermines consumer confidence.

Such an evidence-blind approach may not stop energy saving measures being installed in new buildings – albeit without the means of quantifying whether they proved successful – provided they’re mandated under building regulations. But kickstarting en masse retrofit of existing buildings means convincing consumers to make changes to their home.

Until the day that governments actually force people to upgrade their homes, that means using a mix of incentives and penalties, and giving consumers compelling evidence that they’re making the right choice.

In the case of SuperHomes, Tipperary Energy Agency’s relationship with Limerick Institute of Technology (LIT) – the agency’s founder and chairperson, Seamus Hoyne, is now head of development at LIT – provided an opportunity to prove the concept. The agency partnered with LIT’s Research, Development & Innovation section, who conducted a two-year monitoring study, SuperHomes 2.0. Led by Hoyne and LIT research fellow Padraic O’Reilly in conjunction with LIT’s Mick O’Shea and Geoff Hunter, the study commenced in April 2017 with additional partners of ESB Innovation, Electric Ireland and ESB Networks, and funding via the International Energy Research Centre (IERC) in Cork.

20 homes that went through SuperHomes deep retrofits from 2015 to 2016 were chosen for the study, looking at their performance over

a two year period. 19 homes were fitted with Mitsubishi Ecodan heat pumps, while one had a Dimplex unit. The SuperHomes scheme aims to bring homes up to an A3 building energy rating, subject to what’s possible and cost-effective in a retrofit: the 20 homes in the monitoring study included two A2s, twelve A3s, four B1s, a B2 and B3. 18 of the homes were detached, along with two semi-ds. 15 are rural and five are urban, and the average size is 195 sqm. Seven homes had a mix of underfloor heating and radiators, one had only underfloor, and 12 had only radiators – meaning the heat pumps would have to run at higher temperatures. Some of the underfloor heating was comparatively old, with fairly poor levels of ground floor insulation.

Water tank temperatures were generally set at between 45 – 50C. Immersion heaters were not used for space heating at all, with immersion use restricted to giving hot water an 8C lift up to 60C at the end of the legionella protection cycle once per fortnight, consuming an encouragingly small amount: approximately 70 kWh of electricity annually per house.

The flow temperature range for heat emitters ranged from between 36 and 48C with weather compensation, providing evidence that the strategy of reducing energy demand and thereby enabling radiators to be run at low temperatures is working.

The performance of the heat pumps in all 20 homes was monitored in year one, with their efficiencies assessed in line with a defined seasonal performance factor, which looks

at the total energy input and output of a heat pump. The total amount of heat supplied by the heat pump for space heating and to the domestic hot water tank, added to any heat produced by electric immersions is divided by the total amount of electricity to power inlet fans/pumps, auxiliary heaters, heat pump, immersion and any fans or pumps included in the heating or hot water system.

In year one, the monitored homes averaged SPFs of 3.2 for space heating and 2.2 for domestic hot water – a result which compares remarkably favourably to the Energy Saving Trust’s field trials.

After year one, 15 of the heat pumps were optimised and effectively re-commissioned, with the remaining five left as a control group.

This meant that any improvements in performance gained from changes made to the system could be compared not just against the previous year’s data – which could provide lower or higher performance depending on factors such as the number of heating degree days in a given year – but against other unoptimized homes. The figures improved again: average SPFs of 3.4 for space heating and 2.4 for domestic hot water. By comparison, the EST’s field trials on ASHPs showed SPFs (averaged for space heating & hot water) of 2.45 post-optimisation.

Based on a total of 3,862 and 3,001 kWh consumed for space heating pre and post-optimisation, the costs would translate to annual space heating costs of €574 in year one, and €446 in year two – impressively low figures for relatively large, mainly detached homes.

Pre-optimisation 01/10/17 – 31/03/18

Post-optimisation 01/10/18 – 31/03/19

Average SPF, space heating

3.2

3.4

Average SPF, DHW

2.2

2.4

Average energy consumed – space heating (kWh)

3,862

3,001

Heating degree days

1,707

1,476

Normalised average energy consumed (kWh/Degree day)

2.3

2.0

Average running cost – space heating @ €0.14865/kWh*

€574

€446

* Average electricity cost inclusive of VAT, assuming 50/50 split between night and day rate electricity, based on Electric Ireland Climote electricity price plan from Bonkers.ie.

ph+ | superhomes insight | 57

SUPERHOMES

INSIGHT

Cycling One critical factor that affects both the efficiency and life span of a heating appliance such as a boiler or heat pump is the cycle rate – or the frequency at which the appliance turns on an off to deliver a required temperature.

Padraic O’Reilly explains that EN 15450 of 2007 talks about limiting the number of cycles to three per hour. “ESB Networks documentation on rural connections looks for four starts per hour - because they don’t want big surges.”

After optimisation, the maximum number of cycles was reduced from 14 to 6 per hour.

But the average in year two was far lower: 410 cycles per month. Based on ten hours of heating per day over a month, the average cycle rate worked out at less than 1.35 times per hour. A critical factor in achieving this was matching up of heat pump with heat emission system, by ensuring the operating temperatures are correct. “If they’re too low, you have a mismatch, which causes cycling,” says O’Reilly. Excessive cycling will shorten

the lifespan of the compressor. According to O’Reilly, this was perhaps the main takeaway from the tweaks applied after year one. “The most important outcome of optimisation was the reduction in cycles, at the same time improving the satisfaction of internal target temperature while maintaining or improving efficiency.”

Time-of-use tariff ESB trialled a new ‘time of use’ tariff on eleven of the homes, with smart pay-as-you-go meters installed between April and May 2018 – with in-home displays showing the customer the tariff and their consumption.

The results are encouraging. Electric Ireland’s Aine Doran presented results at the SuperHomes 2.0 conference in April including examples showing users shifting away from the standard profile of usage, with usage peaking in the middle of the night and mid-afternoon – capitalising on the lowest tariffs – and delaying evening usage to peak at 9pm, when pressure

(above) Time of use (TOU) profile with low, medium and high tariffs allocated to six different time slots throughout the day, in order to see whether price could motivate occupants to use their heat pumps outside of peak hours – including at times of low demand during the day, rather than just the simpler day/night rate options.

THE UTILITY’S PERSPECTIVE

best practice heat pump design & installation standards and guidance so that homeowners can have confidence that their low carbon heating system is delivering to its potential.

PH+: What do you think the implications of the results from SuperHomes 2.0 are?

BM: The results have confirmed that heat pumps can very efficiently meet the heating and hot water needs of Irish homes. It has further demonstrated that with the application of best practice installation strategies, further efficiencies can be realised and that scale up of heat pump deployment to meet national decarbonisation objectives offers significant potential. In fact heat pumps offer an immediate climate friendly solution for the 500,000 new homes we are expected to deliver by 2050, avoiding fossil fuel lock-in and guaranteeing sustained carbon reduction without the need for further costly intervention by the homeowner.

PH+: What role does ESB see heat pumps playing in decarbonising heat, and what role does ESB expect to play in this?

BM: ESB believes that heat pumps can make a significant contribution to the decarbonisation of Ireland’s heating sector. An average Irish home currently emits 58% more carbon than the average EU home due to greater use of high carbon fuels. Transferring to electric heat pumps in conjunction with an energy retrofit will offer immediate benefits from a carbon reduction perspective and will deliver co-benefits in terms of creating healthier living environments and reduced energy costs.

Electricity production is transforming with the large scale deployment of renewables having already delivered a 50% reduction in carbon intensity from 1990 levels, with a further 30% reduction envisaged by 2030. Today, ESB is leading this transition to a low carbon energy future, powered by clean electricity. This involves investing in low carbon and renewable generation, developing a smart network

Passive House Plus spoke to project partner, ESB eHeat manager Brian Montayne to discuss the significance of the study’s findings.

PH+: What actions does ESB expect to take based on the information gained from SuperHomes 2.0?

BM: It is our intention that the findings from SuperHomes 2.0 will be leveraged to inform 58 | passivehouseplus.co.uk | issue 30

on the grid is starting to ease.

But what do the homeowners who participated in this study think? Positive-looking hard data is one thing, but the participants in SuperHomes 2.0 also had plenty to say about their upgraded homes. “No matter what the weather’s like outside, it’s always warm once I step inside,” says one homeowner. “Never use the clothes dryer anymore, says another, who finds the combination of consistently warm radiators and humidity-based ventilation is “great for drying the clothes”. Some participants also talked of having homes that are always warm, always having hot water, and the convenience of not having to order fuel – or worry about oil being robbed. But it’s not all positive: “Can’t keep fruit and veg out without it going off,” reported one person.

At the time of writing, the SuperHomes 2.0 project is currently being finalised. 10 of the participating homes also had solar PV arrays fitted, and in one home LIT have assessed the potential for PV output to be matched to the ASHP demand, as well as looking at charging electric vehicles and storage options, working with energy storage specialists Solo Energy.

But the project has already served an extremely important purpose: it has shown that there is real substance in the theory put forward by Tipperary Energy Agency when they launched such a tightly-defined scheme for subsidised deep retrofits, and attracted significant attention from the joint Oireachtas Committee on Climate Action while it deliberated on proposed interventions to drastically reduce carbon emissions across Ireland’s existing housing stock. Only time will tell if the key findings from SuperHomes – not just with regard to the notion of combining specific interventions on energy efficiency, renewable heating and ventilation, but also, crucially, the role of design professionals in the works – end up being heeded.

capable of supporting the further electrification of society and empowering customers to take more control over their energy use. As high carbon electricity generation is replaced by low carbon and renewable alternatives, heat pumps will contribute progressively more carbon savings over time making them a truly future proofed heating option for homeowners.

PH+: Are we likely to see a time of use tariff being launched onto the market any time soon?

BM: We envisage that smart metering will facilitate the introduction of new customer propositions in the years ahead – in the mean time homeowners can take advantage of day/ night tariffs that are ideally suited to all-electric dwellings PH+: Would ESB consider being involved in further research to see to what extent heat pump use has the potential to correlate with wind energy generation?

BM: ESB will continue to support R&D that facilitates large scale deployment of low carbon technologies that will optimally leverage Ireland’s increasing renewable electricity resources.

INSIGHT

SUPERHOMES

ph+ | superhomes insight | 59

E N V I R O N M E N TA L

INSIGHT

QUA NT I FYIN G TH E G REEN NE SS OF C ONST RUC T ION PRODUC TS:

THE RISE OF ENVIRONMENTAL PRODUCT DECLARATIONS Climate breakdown and global ecological crises mean that our efforts to make buildings sustainable must go far beyond operational energy use – including number crunching and drastically reducing environmental impacts of building materials. John Cradden reports on progress in the uptake of the building blocks of life cycle analysis of buildings: Environmental Product Declarations.

A

mid today’s concerns about climate change, the importance of assessing the environmental impact of buildings at all stages of their lifecycles is starting to gain mainstream acceptance.

After all, besides the energy and carbon needed to operate, heat and light a building, the materials to construct it must be quarried, mined or harvested; transported to factories and manufactured; then transported to sites, lifted into place and fixed into position. And over its expected lifespan, a given building will need maintenance, repair and replacement before eventually getting demolished and all its components disposed of, whether that’s through landfill, incineration, recycling or re-use.

To date, it hasn’t been particularly easy to calculate the embodied carbon footprint of

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the materials used in construction, making the already complex job of doing a building life cycle assessment (LCA) somewhat more onerous.

This is where Environmental Product Declarations (EPDs) come in. These are a standardised way of providing data about the environmental impacts of a product through the product’s life cycle.

It’s not in itself a ratings system; a product with an EPD is not automatically a product with a low environmental impact. The EPD only provides the relevant data about the product that you can compare with other products at the building level in order to determine its environmental impact.

“It basically gives you the numbers,” said Jane Anderson, an expert in building life cycle assessment and EPDs. “It doesn’t tell you

whether the numbers are good or bad, but it does give you the numbers consistently.

So then you can take two EPDs and intelligently look at them to see how those products compare.”

However, manufacturers who obtain an EPD will also receive a special EPD report which explains the sources of impacts through the life cycle and enables them to consider how they might best reduce them.

EPDs are also helpful for architects, local authorities and governments in getting good scores for their projects in building rating and assessment schemes like LEED, BREEAM and the Irish Green Building Council’s Home Performance Index.

All of which means that EPDs look set to enter the mainstream of the construction industry as it looks to green its output in

INSIGHT

E N V I R O N M E N TA L

Products with environmental product declarations through EPD Ireland include (clockwise from left) Ecocem cement, KORE EPS insulation, Munster Joinery windows, Quinn Lite thermal blocks and Smartply ProPassiv OSB

response to global issues like climate change.

In Europe, EPDs must conform to two standards: European standard EN 15804 and the international standard ISO 14025, which means that all EPDs should use a common methodology, use a common set of environmental indicators and have a common reporting format.

An EPD will show the impact of construction products over four life cycle stages: manufacturing, construction, day-to-day use and end of life.

It will also report seven environmental impact indicators: global warming potential, acidification, eutrophication, stratospheric ozone depletion potential, photochemical ozone creation potential, and two types of abiotic depletion.

Pat Barry of the Irish Green Building Council, which operates the Irish EPD programme, acknowledges that the global warming potential is the big one. Other factors like the amount of resources that go into making a product and the scarcity of materials are important, but the focus for now will tend to be on the carbon footprint.

“There is a need to educate the market on embodied carbon, so this is part of a longerterm strategy for us to do that. The IGBC program is intended to generate the data, and our next step is to get people using it.”

As you would expect, EPDs have to be independently verified, usually by a third party. Anderson works as an independent verifier of EPDs for a number of the European programmes, including Ireland, Germany, Norway and Sweden.

She agrees that the EU has been the driver of efforts to harmonise standards for EPDs throughout Europe but also worldwide.

There were EPD programmes in the UK,

Holland, Sweden and Germany, but “they all had different rules, different indicators and different approaches, and it literally meant that manufacturers were having to do completely different studies in each country if they produced a product that was exported”.

“It was the European Commission that then gave CEN, the European standards body, a mandate to harmonize the approaches and to produce a European standard at both the products and building level.”

There are, of course, EPD programmes outside the EU, including in the USA, Canada, Australia and New Zealand, but they have all adopted the European standard as the basis for their schemes.

EPD growth According to 2019 data compiled by Anderson, there are now over 6,000 EPDs for construction products that conform to EN 15804 worldwide. So while there has been “strong but not exponential growth” in the adoption of EPDs, Ireland and the UK are somewhat behind the curve compared to other European countries, particularly France and Germany. France has over 2,000 published EPDs between two different programmes, closely followed by Germany with just over 1,300, and Norway with over 500.

“Basically, France has environmental regulation that says if you want to make an environmental claim about the products in France you have to have an EPD to justify it,” said Anderson.

“There’s no obligation to make an EPD, but if you claim your product is low impact, or it’s got a low carbon footprint, or it’s better than somebody else’s, then you have to basically have an EPD. That’s kind of driven the numbers there.” Anderson adds that France

has pilot regulations and requirements to reduce the embodied carbon of buildings and increase the use of renewables. “So, there’s a kind of driver in two directions,” says Anderson. “There’s a quite rapid growth there.”

In Germany, there is a widely adopted building lifecycle assessment scheme that requires the use of EPDs, which has driven uptake there, while over in Norway, take up is being driven by both the public authorities and the widespread use of BREEAM, along with what Barry describes as a “very advanced” lifecycle assessment scheme.

At the time of writing the UK has 168 and the Irish programme (which in fairness was only launched by the IGBC in 2017) has 15. Of course, relatively few construction products are manufactured in Ireland, with just five companies having published EPDs through the Irish programme covering a select range of products, according to Barry, but there are about 500 imported products with EPDs available in Ireland that have been published through other programmes such as the IBU in Germany or the BRE in the UK. One other driver of the take up of EPDs is a European Commission initiative called Levels, a voluntary reporting framework which aims to provide a set of indicators and common metrics within the EU for measuring the performance of buildings along their life cycle. This is something that Barry says should drive transparent data for EPDs because “it kind of incentivises quality data”.

Software tools While all this might sound like another layer of bureaucracy and paperwork to many in the construction sector, the good news is that there is software available that can make

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E N V I R O N M E N TA L

INSIGHT

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To book your place, or to find out more details, visit www.aecb.net/carbonlite/ carbonlite-retrofit-training-course the Association for Environment Conscious Building AECB, PO Box 32, Llandysul, UK SA44 5ZA t: 0845 456 9773 e: membership@aecb.net

INSIGHT

Pictured with their EPD certificates are (far left) Jason Martin of Quinn Building Products; (left) Munster Joinery’s Marlene O’Mahony; (right) EPA director Eimear Cotter; and (far right) IGBC CEO Pat Barry.

producing an EPD much easier.

The IGBC, for instance, teamed up with leading Finnish LCA experts Bionova to allow building professionals to quickly calculate the embodied carbon in a building through their One Click LCA software. The web-based application takes the legwork out of calculating a full LCA, reducing the time to a matter of hours rather than weeks and is now more akin to working out a BER. Panu Passusen of Bionova says a bit of training is required to use the application, “but it is as much training in LCA concepts as in the use of the software”. Training can be included with licences. Users can hit the ground running after 2-hour training for building level studies, while for EPD studies one day is required.

Making the process easier is also crucial to drive the registration of EPDs, as Anderson points out that the figures she compiles do not include EPDs that are not registered or published in any programme.

She has used software tools for calculating LCAs and EPDs, including one time with British Precast, the trade association for precast concrete manufacturers and suppliers, to produce an EPD for the average aircrete block and for the average hollow core floor. “All of their manufacturers can actually use that tool to produce an EPD for any of their products...they can use those tools to produce EPDs on demand and the tools have been verified, so there are lots more EPDs that are around that but aren’t registered with an EPD program.”

Of course, it you take a lock manufactuer like Assa Abploy, who have 10,000 different products, then it’s not financially viable or practical to produce EPDs for all of them, so it may only make sense to register the significant ones, she says.

“So, there’s a balance between trying to make sure you’ve got significant products registered and that you can produce them if you need to.”

Role of architects However, there is still a bit of the chicken and

the egg regarding the promotion of EPDs; it’s clear that architects need to play a bigger role and start asking for them, says Barry.

“We get it all the time from manufacturers that they do not produce any EPDs because they do cost money and because architects don’t ask for them. So the key issue is that architects aren’t aware of them or why they should ask for them.”

Two exceptions in Ireland are Dublinbased practices RKD Architects and Coady Architects.

Simon Keogh at Coady Architects says that it recently used more than 25 products on a 20-unit development in Rathdrum without knowing they had EPDs but is now aiming at using 50 products with EPDs on a 42-unit project in Kilbride without any issues over cost or procurement. However, he does believe there is work to be done in pushing product manufacturers to get moving on EPDs in a timely manner, and also to deliver training in LCA software to make use of EPD metrics.

Coadys is also working on completing one of the first - if not the first - building LCA in Ireland in Rathdrum in conjunction with Technological University Dublin.

Matthew Reddy of RKD says his firm’s exposure to EPDs initially arose from projects that were seeking LEED or BREEAM project certification. “In these green building certification schemes, credits are available when project teams specify products with third party-verified EPDs.” After a bit of market and product research, the firm opted to focus on products that were independently verified and meet the EN and ISO standards. “From this research we developed a database of products which align with typical material specifications for a range of building typologies.”

Manufacturers Ecocem has recently updated its EPD for its cement to show a 24pc reduction in embodied CO2 emissions compared with its previous certificate. To put this in perspective, the carbon footprint of

E N V I R O N M E N TA L

cement is approximately 850 - 900kgCO2/t (Ecocem’s GGBS at 32kg of CO2 is approximately 96pc lower).

Ecocem’s Micheal McKittrick, recently appointed managing director for Northern Europe, notes that there are options in the market to significantly reduce the embodied footprint of cement.

“The most effective way to demonstrate that is via EPDs, which are governed by EN 15804. If we want to feed the changing atmosphere on life cycle assessment, the EPD is the single most effective means in doing that”. McKittrick believes that regulation needs to be given more teeth to drive building life cycle analysis here, to reflect the practices elsewhere in Europe such as Holland and France.

Andrew Butler of KORE says his firm started working on creating its EPD for its EPS board in 2018 after the launch of the Irish EPD programme by the IGBC, and published it just last February.

Although there was quite a bit of work involved, including breaking down all the parts of the manufacturing process and analysing them, the company was able to learn quite a bit of useful information in the process, he said. This information was used to enhance production efficiency, and gain greater control over the use of secondary materials like water and packaging. “Staff at KORE gained a more rounded knowledge of the impact on the environment of what we do.”

Butler says KORE’s products conform to other EN standards that include strength, dimensional stablility and water absorption, but the EPD is the “first independentally verified method to allow us, as a manufacturer, to share transparently our product information with the construction industry while helping them look to the future”.

Irish wood panel product manufacturer Medite Smartply supplies a wide range of products and has an EPD for every one of them. The fact that some of them are a variation on a base product could have feasibly allowed them to do an EPD just for this base product, but they chose not to. For example, its OSB3 board is the base sustrate for its Site Protect, Propassiv, and Pattress Plus products, but “each has a slightly different finishing process, e.g. coating or machining, which will alter the carbon footprint, and only very slightly, but we want total transparency,” said David Murray of Medite Smartply.

But what probably helps is the use of a new LCA software application made by Dutch firm Ecochain.

“As well as providing us with LCAs and EPDs for our entire MDF and OSB product range, the Ecochain tool allows us to benchmark, monitor and reduce our greenhouse gas emissions as we continually invest and modernise our processes,” said Murray. “We can also analyse the environmental impacts of the materials we purchase, so that they, too, can be substituted by lower impact materials when the opportunities arise.”

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GUIDE TO

Old Holloway, an award-winning certified passive house in Hereford - a good example of a low energy building with sensible glazing ratios, substantial overhangs and additional awnings to ensure summer comfort.

The PH+ guide to

OVERHEATING As awareness of the urgency of the climate crisis grows, efforts to kickstart en masse deep energy efficiency interventions are gathering apace. But poorly conceived low energy building efforts can lead to unintended consequences including overheating – a risk that’s bound to grow as the world warms up. Phi Architecture co-founder Claire Jamieson details the risks and offers some solutions on how to create low energy buildings that are comfortable in summer and winter.

I

t is our British and Irish prerogative to embrace spring with the opening of windows and the circulation of “fresh air” – to brush away the winter cobwebs, so to speak. This is closely followed by the summer season where the evening light is beautifully extended by British Summer Time and Irish Standard Time. So, we grasp every opportunity to “live” outside, satisfying our perpetual determination to have a barbecue or a summer gathering, with umbrellas on standby. We have our windows open at night, whilst the air is not too bitter and enjoy the morning chorus of birds.

For plenty, this is a dream, far from reality and perhaps only experienced on a holiday.

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Urban environments, social housing and low-grade suburban sites often have limitations in the form of noise, crime and air pollution which make it unpleasant to introduce the external environment into private living space.

In the cities, many people occupy high/ medium rise flats. These can be single aspect as we are aware, those on the southwestern side at the top of the building will suffer most from overheating. Building services within the core and the nature of heat rising through such spaces, as well as no opportunity to cross-ventilate can mean that temperatures get uncomfortably high. Vast expanses of glazing on modern apartments where

shading has not been “designed in”, or poorly fabricated old building stock, both allow large amounts of heat transmittance through the building fabric.

City living has added complexities such as the urban heat island effect – hard landscaped ground temperatures are 10% greater than in rural locations. In addition, there is extensive heat generation from rooftop plant and refrigeration systems, and perhaps some from transportation. Not to mention the influence of the other immediate milieu of buildings such as the widely reported “Walkie Talkie” in London. This and further new developments are sometimes the culprits of further overheating effects on their surrounding

GUIDE TO

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1 In the graph above, two zones are shown— one for 0.5 clo of clothing insulation and one for 1.0 clo of insulation. These insulation levels are typical of clothing worn when the outdoor environment is warm and cool, respectively. The operative temperature range allowed for intermediate values of clothing insulation may be determined by linear interpolation between the limits for 0.5 clo and 1.0 clo, using the following relationships: 1 clo = 0.155 m2 °C/ W (0.88 ft2·h·°F/Btu). - extract and graph from Ashrae Standard 55-2010 Thermal Environmental Conditions for Human Occupancy; 2 Walkie Talkie, London. The nickname for a skyscraper at Fenchurch Street in London, which earned the additional nickname “death ray”, and which was reported to be damaging neighbouring buildings and parked cars due to reflected light.

existing urban dwelling stock.

The concern over these unmeasured external influences can be summed up in a marvelously succinct phrase I acquired from Michael Swainson, principal engineer, BRE: “The context is always forgotten”.

We have: • the ability to reduce our propensity to extend hard urban landscapes and introduce more green spaces, trees and associated natural shading. We also can include rooftop permaculture.

• the knowledge to consider the further context, orientation and aspects, security, noise and pollution, glazing and U-values, all in our design.

• the opportunity for the support of M&E expertise to design in purge ventilation for the heat stacks and sumps of services.

In the new suburbia where a generic gallimaufry of architectural references seems to offer a desirable familiar environment to many, the siting and orientation of dwellings tends to be by way of a generic and alluring site layout. This can lead to many of the houses having a poor orientation both for overheating and winter solar thermal gain. Positioning, altitude, exposure, site location and perimeter influences, such as other buildings and trees, are not seemingly

embodied in the process of designing these houses. The “style” is solely a reflection of the pastiche expectation of a “home” as opposed to being truly designed in terms of quality of life through context, daylight, warmth, privacy, energy conservation and summer comfort.

Social housing schemes, often sited where the developers and councils consider least prospect of financial gain, suffer hugely from minimal design, and little attention to energy conservation, user health or comfort. They habitually get demoted to locations where they act as a buffer zone between motorways or rail lines and the remaining development of less affordable housing.

7730) that there are six factors that influence thermal comfort. Four are environmental and two personal: 1. Air temperature It is generally assumed that a temperature of over 24C is uncomfortable, but temperature considered in isolation can be delusive.

2. Radiant temperature Determined by surfaces that radiate heat either because they have absorbed it or because they are becoming hot through operation. A metal surface that has had the sun shining on it; or an oven.

3. Air velocity The movement or air within a space, through activity, convection, air leakage/draughts.

We have: • t he knowledge to introduce a new approach to suburban living but need the support of developers and end users.

• t he capacity to create better social housing with the support of councils and housing associations.

4. Humidity Acceptable levels ≤ 50% in order to prevent dust mite infestations, mould and bacteria growth and reduce the outgassing of VOCs, but as low as 30% in winter to avoid condensation on cooler surfaces.

When faced with these complex scenarios, where do we begin to understand, in particular, what summer comfort is and how it is evaluated?

The Health and Safety Executive has determined from Fanger Comfort Analysis (1982 - Fanger’s equation, documented in ISO

5. Metabolic rate People have different metabolic rates that can fluctuate due to activity level and environmental conditions. Among the factors at play here is body shape - tall skinny people for, instance, have higher surface area to volume ratios, and therefore can dissipate heat more and tolerate higher temperatures.

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GUIDE TO

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2

1 Sliding shutters were installed on the windows of the Cameron Close passive house scheme on the Isle of Wight to provide shading and reduce the risk of overheating; 2 a passive house in Bessancourt, France, which features untreated bamboo cladding - including within adjustable shutters which can shade or open up the house as necessary.

6. Clothing insulation The amount of thermal insulation worn by a person has a substantial impact on thermal comfort, because it influences heat loss and consequently thermal balance.

These six strands can be considered in relation to the Ashrae Comfort Factors to appreciate the instinctive senses that are associated with discomfort and thus the design initiatives we can execute to counteract such eventualities.

• r adiation temperature asymmetry needs to be less than 5C • t he indoor air stratification needs to be less than 2C between ankle and head • t he perceived temperature difference across locations within dwelling must be less than 0.8C • t he air speed needs to be less than 0.08m/s (air speeds due to free convection at cooler surfaces) In principle it is understood that our comfort zone falls into lower temperature bands with an increase in clothing, metabolic rate and radiant temperature and accordingly into higher temperature bands with a decrease of the same. PHPP – the software used for the design of passive houses – evaluates designated occupancy levels based on floor area. The real time occupancy will fluctuate around this value.

On considering these parameters in relation to the “context” of a building, the raised internal air temperature and humidity, when influenced by the external summer environment, may become uncomfortably high.

The radiant temperature of the fabric of the building and the ability to control effective air velocity and humidity, are the three parameters which require our most careful attention.

In a passive house, through PHPP, we are able to tap into these factors to some extent in our modeling. We are also able to address air temperature gains from internal influences.

Perhaps to demonstrate by a few examples:

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• design orientation of the primary aspect as near to south as possible – to maximise winter solar gains when the sun’s arc is low, and minimise gains when the sun’s arc is high in the summer • consider the location and use of reflective heat absorbent surfaces • consider orientation of glazing and percentage of glass in any one elevation • design in the correct ‘g’ value and thermal performance of glazing relative to every aspect and consider location and the minimization of thermal weakness in transoms and mullions • consider openable lights for summer cooling, where there are desirable external environments • limit use of floor to ceiling glass where overheating is exacerbated towards the lower 1/3rd • consider permanent external shading from high summer sun, as an architectural feature of the design • aim for uniformity of U-values to avoid large differentiations in the thermal performance of the building fabric • use low energy lighting (this is now standard) • use A++ insulated appliances • optimise insulation of hot water systems and associated distribution.

Passive house, as a standard of construction, embraces all shapes, sizes and styles of architecture. It affords a universal median by which the insulation, shading, airtightness and designing out of thermal bridges can act as controlling factors in both summer overheating and winter cooling. If we work with this principle but accept and understand its limitations and need for further contextual parameters, we are at least moving some way towards a more sustainable and design-engineered solution in our architecture.

Architect and certified European passive house designer (CEPH) Eric Parks of Buckrose Ecological Architects offers a positive

response to support such enthusiasm to adopt passive house measures.

“I have anecdotal evidence from one of my passive house clients who moved into his rural, detached passive house before the heat wave last year,” says Parks. “He found that the house would get up to 25C (max) during the peak of the heat wave and whilst he was out during the day at work. However, this heat was easily dissipated / returned to a comfortable environment within minutes of arriving home and simply opening two sets of French doors in the evening to purge and cross-ventilate.” Parks is wary of overheating risk. “It is a [considerable] risk with any super-insulated and airtight design, though with a few robust mixed-mode ventilation options, this can be managed.” However, likewise, he goes on to say: “I appreciate that when the conditions are different – say an urban site where traffic noise or security may be an issue, then a different design solution would be required”.

The passive house design package is constantly evolving. Rob McLeod, senior lecturer at London-Loughborough EPSRC Centre for Doctoral Research in Energy Demand, has offered assurance that sustained development and challenging of the modeling process is leading to further confidence in the real performance of PHPP modeled buildings.

Algorithms are being developed to trade off energy performance vs cooling vs daylight, thus encouraging a maximization of all the features passive house can offer. The more that PHPP is tested and recorded, the more factual data we can evaluate and thus the more refined and sensitive the data input can be in determining the best outcome for every project. “It would be counter-productive if widespread overheating risks were an unintended consequence of meeting the passive house standard,” says McLeod.

“Assessing whole-life performance at the design stage is the best way to avoid this and deliver truly resilient buildings.”

Even if we are not consistently building to passive house standards, there are so many

GUIDE TO

achievable aspects of passive house principles that can become common practice amongst trades. It is not too late for us to encourage and support changes in practice and application, to educate the inspiring and pro-active youth of today in passive house principles and to encourage all aspects of renovation and construction to be approached with such principles in mind. This, in itself, is a small stepping-stone towards more comfortable living which can progress without waiting for the tardiness of our government to wake up to such needs for further legislation and more robust regulation.

Our environment has a prodigious impact on how productive, healthy and happy we are. I ask, why we are so sluggish in formalising legislation which enforces us to act according to the extensive knowledge and understanding we have through the ever evolving and improving passive house principles? Perhaps, amongst other much bigger factors there is some reticence because of the nervousness of its long-term performance in terms of overheating?

Accordingly, in consideration of “overheating”, certified passive house consultant and Green Building Store director Bill Butcher was in instant agreement with his colleague, passive house technician Paul Smith that we should “design it out. Not doing so can lead to expensive and sometimes complicated shading. Solar thermal gain must be optimised in a passive house design rather than being maximised to the point that it compromises the summer comfort.”

In parallel, honest and critical analysis as to the realistic end user application of summer shading strategies needs to be evaluated.

The building regulations continue to update, addressing energy conservation and comfortable living, through “improvements” in U-values, ventilation and airtightness in

Part L and Part F. Regrettably these do not yet offer a robust overheating strategy. To top it all we find that, amongst other flaws in the suggested assurances of this regulation system, it seems that it is almost invariably not being seen through on site, making such a mandate futile.

SAP is the customarily accepted energy performance tool associated with the Building Regulations for dwellings in the UK, aimed at ensuring new homes are more “energy efficient”, However, it is well documented that this system offers inadequate attention to the matter of summer cooling and is not always robustly and honestly applied. New homes today can be uncomfortable, hot and stuffy, and this can lead to high levels of CO2 in indoor air.

Associated impacts of this are poor sleep quality, tiredness, agitation and lack of concentration. Studies in schools, hospitals and care homes draw parallel conclusions and yet we continue to construct and refurbish to knowingly inferior standards.

When we endeavour to apply the extended knowledge of passive house through PHPP, without the support of legislation, we are at the mercy of the client, their quantity surveyor and funding. It is their discretion which determines if such investment is value added.

With the support of new measures within building regulations, with a whole house, holistic approach to overheating/ventilation, we could more easily ensure support for summer comfort. Should this be backed up by the ARB and RIBA in the UK and the RIAI in Ireland through our code of conduct we would be obliged to bring the science back into architecture.

We know we can marry outstanding design with improved summer comfort. It entails a duty under professional architectural services to design for performance, owning respon-

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sibility for the comfortable occupation of the end product. I have worked with colleagues who are amazing designers, addressing spatial concepts and occupiers’ visual experience, but this cannot be at the cost of summer comfort and consequent unbearable internal temperatures.

The need to reach far beyond current day climate data, surpassing modelling for the here and now, is recognised. Our climate will not just become warmer but also more extreme in terms of hot and cold, wet and dry.

We require future proof design using design summer year data projecting to at least 2050.

We can do this without waiting for government to act in setting a trajectory of standards, regulations and targets for new homes, ensuring they are fit for 2050 and beyond.

Those of us who care about our future generations and our planet wish to address climate change and the comfort factors needed due to irreversible change to date – change that we cannot now arrest. We can build environmental design back into all levels of architecture by addressing heat gains and how to purge them. We can make a difference to our summer comfort and hand-in-hand with this, work to reduce future projected energy consumption through mechanical cooling.

As McLeod et al have noted, almost all houses in the existing UK stock will overheat in the future and some of this will be to chronic levels: “Unless there is a move towards whole life design optimisation based on minimising future overheating risks, active cooling systems may become a de-facto requirement in urban passive house and low energy dwellings in the UK within the next 30/40 years.”

As clients, developers, architects and builders we can lead by example, addressing the life of the building, its context, occupancy comfort, well being, daylight quality, fresh air and sustainability. This in turn will lead to healthier, happier occupants, less morbidity, lower running costs and less need for retrofit cooling action.

There are, of course many angles to comment on when it comes to overheating – many that stretch far beyond this article but are undoubtably valuable. So here are a few additional thoughts to close with: • seek the truth behind all the assumptions we make from so called reliable sources and perhaps consider that lack of action by government and large institutions may not be anything but a smoke screen for financial gain at all costs • consider the power of conscientious humans through research, professional specialism, craftsmanship • through the work that appears on the media, consider the information in reporting and actions such as Our Planet, Extinction Rebellion and Cowspiracy, to name a few.

above A NASA temperature anomaly map in Northern Europe in July 2018 showing unusually hot conditions in Ireland, the UK and Scandinavia.

If we can share the world rather than consume and obliterate it, we should have less of an overheating and summer comfort crisis to overcome.

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MARKETPLACE

PA S S I V E H O U S E +

Marketplace News MVHR myths still persist — CVC Direct without it.”

“One does not really notice negatives. For example, you don’t notice that there is no condensation on windows, or that there are no mould spots, or that there is much less dust in the house and occupants are generally healthier,” he said.

Bartlett said that while the technical features or economic benefits of MVHR are often the most emphasised, arguably the biggest benefits are to occupant health. • (above left) Graphic showing a Brink Renovent MVHR system in a typical dwelling.

ECOMERCHANT COMPETITION WINNERS PICKED

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eading mechanical ventilation with heat recovery (MVHR) supplier CVC Direct believes that despite the growing popularity of MVHR, there are still many misconceptions about the technology among both general consumers and the building sector.

CVC Direct’s Tim Bartlett told Passive House Plus that two of the biggest misconceptions the company encounters are that MVHR is a heating system, and that it provides air conditioning. It is neither, of course — MVHR provides reliable ventilation by extracting warm moist air from kitchens, bathrooms and WCs and supplying fresh, filtered, warmed air to bedrooms, living rooms etc.

Bartlett says the company also often gets asked what the payback time on MVHR

systems is. “There isn’t one,” he said. “The payback comes from the vast amount of insulation it allows to be used in an airtight house. It will actually cost money to run, typically £30 to £50 per year, but a passive house will save many times this amount on heating bills.”

Another misconception is that it causes a dry atmosphere in a house. “Possibly in Central Europe but not in the temperate climate of UK or Ireland with prevailing winds from the Atlantic.”

Bartlett said that when an MVHR system is installed and working well, the benefits can often go unnoticed. “A frequently heard comment from people with MVHR already installed is that they don’t really know that they have got it — but they wouldn’t be

Sustainable building product suppliers Ecomerchant recently ran a competition offering six free annual subscriptions to Passive House Plus to their customers. The lucky winners were picked by National Self Build & Renovation Centre (NSBRC) MD Harvey Fremlin, pictured here with NSBRC marketing manager Emma Walker.

Lamilux smoke vent rooflights suitable for passive house

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longside its portfolio of passive house certified skylights and roof glazing (phA advanced components) Lamilux has extended its product range to include Smoke Vent AOVs (automatic opening vents). AOVs are designed to automatically vent air or smoke in event of a fire.

With a complete product range for performance led-buildings, Lamilux Smoke Vent AOVs have been used in buildings that have gone on to achieve passive house certification, the company said.

Lamilux is one of Europe’s most established and experienced manufacturers of daylight systems specialising in the design, supply and fitting of quality rooflights for buildings. All Lamilux rooflights are fully CE marked and BIM-ready.

The Lamilux range of rooflight and atria glazing systems offer trademark features including an attractive design and architectural charm, coupled with the highest level of airtightness and excellent heat-insulation values. Alongside this, the portfolio boasts exceptionally watertight properties, which guarantees no leaks in

68 | passivehouseplus.co.uk | issue 30

extremely high winds and driving rain, and effective soundproofing, which reduces the impact of unwanted noise to the interior. •

(above) Lamilux automatic-opening smoke vent.

PA S S I V E H O U S E +

MARKETPLACE

Kingspan & Nulok launched insulated roof system

Passive Purple excels in airtightness challenge (above) The dilapidated test building during its airtightness test, after application of Passive Purple.

T

he application of Passive Purple Liquid airtight membrane to a dilapidated test building has demonstrated the product’s remarkable ability to air seal even the leakiest structures.

In April, Intelligent Membranes was asked by Beattie Passive, the leading manufacturer of offsite passive house building systems, to visit the company’s manufacturing facility in Norfolk and test its Passive Purple product on a 58m3 test building that was chosen because it was expected to be very difficult to air-seal.

The test structure’s walls were of 63mm studwork with MGO board as the main fabric, with gaps of 5mm between each of the boards, and a roof of 6mm ply which had been left exposed to the elements for four years, and lost all structural integrity and shape.

The team set off by applying Passive Purple Brush to hand-fill joints and gaps, seal the service gaps and correct the split ply and warping in the roof. Next came the Passive Purple Liquid, the spray/ roll applied liquid airtight vapour control membrane, with the team making sure the building fabric was completely covered. Then came the air permeability test.

“With the test underway it was already easily noticeable that the structure was very airtight because there was zero cold air or drafts passing through the structure,”

said Alex White of Intelligent Membranes.

The building was both pressurised and depressurised, and produced a test result of 0.35 air changes per hour at 50 Pascals, well inside the passive house standard of 0.6.

This was particularly impressive given the thin building fabric of just 6-9mm, and the tiny size of the structure.

After the test, Nathan Beattie of Beattie Passive referred to Passive Purple as, “the holy grail of airtightness, a product unmatched in quality and results.”

Next up came the smoke test, when the inside of the structure was completely filled using two smoke pellets and then pressurised to see if any smoke was escaping, with the structure proving completely airtight.

“This airtight result is what Passive Purple can guarantee on any substrate it is applied to with the backing of its BBA proven certification of 0.6 air changes per hour or under,” said Alex White.

“We can guarantee the highest level of performance for our liquid applied membranes, whether it be for airtightness, waterproofing or substrate protection.”

“As long as you understand the fundamentals of airtightness, anyone can use and apply Passive Purple Liquid airtight vapour control membrane.” •

L

ong-term partners Kingspan Insulated Panels and Nulok have combined their innovative pitched slate and tile roofing systems to create a slim, versatile solution that offers the benefits of insulated panels with the aesthetic appeal of traditional vernacular roof finishes, all in an easy to install package.

The Kingspan Slate & Tile Support System comprises high-performance insulated panels capable of achieving U-values as low as 0.12 W/m2K with a factory-fitted weather seal. This provides the ideal base for the Nulok Roofing System – a simple yet durable fixing method for natural slate, ceramic tiles and even integrated solar PV panels.

High-quality steel battens and link channels are installed over the insulated panels with specially designed fixing screws, creating an interlocking grid system that eliminates the need for timber. The chosen exterior roofing materials are then simply slotted into place and held by stainless steel clips to create a secure finish, even on roof pitches as low as four degrees after steel deflection.

In addition to simplifying the installation process, the lightweight solution helps to reduce both the depth of the roof build-up and material requirements, using 50% less slates than traditional systems. The entire solution is also covered by the Kingspan 25-year system warranty. • (above) High performance Kingspan insulated panels provide the ideal base for the Nulok roofing system, a simple yet durable method for fixing natural slate, ceramic tiles & even solar PV.

ph+ | marketplace | 69

MARKETPLACE

PA S S I V E H O U S E +

Monolith ensures traditional finish on new ICF project

W

hen looking at new technologies and projects, developers and self-builders might assume that if you’re building with ‘new’ methods such as ICF, SIPS, timber frame and steel frame that you can’t achieve a traditional facade.

Most buildings showcased today aren’t inherently traditional, most are rendered and timber clad – but a traditional effect finish is still possible very much possible even with newer, highly energy efficient forms of construction.

As a case in point, innovative exterior cladding supplier Monolith recently completed a project with a developer in Manchester who was intent on building his latest project in insulated concrete formwork (ICF), but due to planning conditions needed to ensure that it resembled local properties.

The ICF system specified on the project was

Warmerwall from Polysteel. Monolith was in conversation with the developer, architect and planning committee from the outset to ensure the products it manufactured suited the local aesthetic.

“Once we created a brick match and stone colour sample it was then sent to the developer to present to the planning committee, these were approved and ordered by the client. We then went into full production and provided our BrickPlus: Eco panels and StonePlus profiles to the developer who used a registered Monolith installer to correctly and efficiently apply the product,” Edd Wilson of Monolith explained to Passive House Plus.

BrickPlus: Eco is Monolith’s innovative insulated brick cladding system, which replaces traditional block and brick when used with either ICF, timber frame, steel frame or solid wall construction. It consists of 12 of

the company’s high-quality brick slips which are bonded to lightweight, fire retardant, high grade EPS panels. This forms a system of interlocking panels that can dramatically increase the speed that a brick slip wall can be covered.

StonePlus is a true alternative to traditional stone. Available in a wide variety of authentic and traditional stone colours, StonePlus is the natural finish for any building. The main feature of StonePlus is that it is extremely lightweight. Whilst it has the same look and feel as stone, it is around 75% lighter, but equally as strong and weather resistant, according to Monolith. For more see www. monolith.build. • (above) The ICF-built development at Sherratt Close in Manchester was finished with BrickPlus: Eco & StonePlus finishes from Monolith.

GreenTEG launches cloud-based insulation monitor

G

reenTEG AG has launched the gO Measurement System (gOMS) for wireless, cloud-based U-value, temperature, and humidity measurements. The gOMS is the ideal tool to make non-invasive insulation quality assessments, for example before refurbishment of an older building, the company said.

Other applications include the detection of mould-prone spots. The system generates hard data about the insulation quality and humidity values.

Up to 16 sensor nodes for temperature, heat flux, and humidity measurements can be connected to the base station. The data from the sensor nodes is transmitted via LoRa (long range) technology to the base station from where the data is sent to the cloud via a secure 3G connection.

The data can be monitored remotely and in real-time.

There is no need for software installation: to view the data one simply logs in to the portal with a browser. For more information see www.greenteg.com/gO-Measurement-System/. •

70 | passivehouseplus.co.uk | issue 30

(above) The GreenTEG gO Measurement System.

PA S S I V E H O U S E +

MARKETPLACE

FOCUS ON WHOLE BUILD SYSTEMS, NOT PRODUCTS — NBT

A

s construction delivery chain roles have become more fragmented, a lack of joined up thinking has meant that disparate elements of a project don’t always work effectively as a whole, says Andrew Mitchell, managing director of Natural Building Technologies. A primary example of this is the critical interfaces between different building envelope elements, particularly structural, acoustic and thermal elements.

Unresolved aspects of the design are often ‘discovered’ during the construction process, leading to delays, waste and bad solutions that can result in significantly

increased costs and poor final results.

But the elements within the envelope build-up can only deliver their designed performance if the interface is fully-integrated to prevent thermal bridging and heat loss. If the interfaces are not as robust and well-detailed as they appear on paper, we lose the opportunity for creating more thermally efficient and airtight buildings, while adding significant construction cost through increased time, increased material waste, and failures that can lead to costly snagging.

For some, part of the answer is modular construction and NBT is involved with a

number of modular specialists, creating envelope solutions that deliver real, measurable thermal performance, without compromising the integrity of the building or the health of the occupier.

There are also lessons to be learned from the modular approach for the less uniform world of on-site construction. NBT has been pioneering this philosophy by providing new build ‘systems’, as opposed to single product offerings, for the building envelope.

These consider the full foundation to wall to roof build-ups for different types of construction, and provide a total solution for the interface design, with an inclusive package of products to cover everything required for consistent installation.

NBT has developed numerous complete interface details to ensure that specific design expertise is invested in the interface.

The company’s systems include solutions for brick clad timber frame structures as well as cross-laminated timber, steel and concrete designs with both clad and rendered external finishes. The company has also developed interface systems for both flat and pitched roof, and foundation build-ups. Next up the company is planning to launch a new raft foundation system to complete the thermal envelope. For more see www.natural-building.co.uk. • (above left) Pavatex woodfibre insulation products form key part of NBT’s build systems.

MVHR owners sought for air quality study G

reen Building Store and PHI Architecture are currently seeking property owners with MVHR systems to take part in air quality research in conjunction with Nottingham University.

MVHR systems have an intake filter which PHI Architecture say should be changed every 60 days or so, and which cleans incoming air as it enters the property. Quite often this filter, on removal after 60 days, will look quite clogged and dirty.

The team behind the research is asking potential participants to send two small 10 x 4cm samples cut from the filter each time it is changed. On registering interest, the researchers will require the address at which the MVHR is operating, the MVHR make and model, and the filter type.

All the samples will be anonymous, and the actual addresses only known to the research team involved. Participants will be sent a self-addressed envelope to avoid any postage costs.

The researchers will aim to share all findings with participants and to develop a map of the pollutants found in the samples. They also hope to present findings to the environment secretary to further improve action in accordance with the government’s clean air strategy. All results will be presented as aggregate data and no individual property will be able to be identified in any report or research publication. Participants will be able to withdraw from the study at any stage of the research. To register your interest, see tinyurl. com/mvhrfilters. •

(right) Samples of material trapped by MVHR filters will be analysed as part of the study.

ph+ | marketplace | 71

MARKETPLACE

PA S S I V E H O U S E +

Wool insulation purifies indoor air — Sheep Wool Insulation

Tyvek launch new airtightness accessories T

yvek has launched a brand-new suite of airtightness and building envelope accessories to complement its breather membranes and AirGuard range of air and vapour control membranes.

The company said these additions to the specialised adhesive range make Tyvek the one-stop-shop for ensuring the integrity and airtightness of the building envelope, from timber frame housing to high-rise construction.

“With all the lasting quality and premium adhesion one would expect of the brand, many elements of this complete and compact offering are ‘universal’ products suited multiple applications, thus simplifying installation and saving on time and cost,” a statement from the company said.

The new range of airtightness accessories include: • Tyvek Double-Sided Tape: double-sided acrylic tape ideal for temporary fixings of a vapour control layer.

• Tyvek Plastering Tape: high performance airtight and moisture adaptive carrier tape that can be rendered. It seals difficult areas such as windows, doors and timber to block connections. A product for both interior and exterior application.

• Tyvek Sealant: an adhesive sealant for permanently elastic, airtight bonding of joints and structural connections, plus connections of AVCLs to many different surfaces.

• Tyvek Primer: transparent primer that is permanently tacky after curing, with a very fast curing time. It is recommended for high-porosity surfaces to create good adhesion.

• AirGuard Tape: high performance flexible and hand-tearable tape to seal difficult areas such as corners inside the building with a very high tack.

These come in addition to the recently launched Tyvek Flex Wrap EZ and NF, a high performance flexible self-adhesive flashing tape for airtight and watertight seals around windows, doors and multiple custom shapes or awkward penetrations.

Other products in the range include Tyvek Acrylic, Tyvek Butyl and Tyvek Metallised tapes. The Tyvek family of products comes with expert technical support from a global knowledge network to help construction projects meet every key target – from safety to sustainability, the company said. For more see www.energy-efficiency.dupont.com and www.construction.tyvek.co.uk. • (above) The Tyvek range of airtightness tapes & accessories.

D

esigners, contractors and self-builders looking to protect indoor air quality should consider wool insulation for its natural ability to remove volatile organic compounds (VOCs) and purify indoor air, according to leading Irish supplier Sheep Wool Insulation.

While environmentally minded homeowners and specifiers are increasingly choosing natural paints and finishes and low-VOC products in order to protect the quality of their indoor air, even natural wood products can emit quantities of potentially dangerous VOCs like formaldehyde, and many common household products and finishes emit VOCs. However, speaking to Passive House Plus, Aisling MacDonald of Sheep Wool Insulation pointed to peer-reviewed research demonstrating that wool can remove such VOCs from indoor air. “Sheep wool is able to purify the air in a room within a very short space of time, removing many odours and harmful substances, such as formaldehyde.” She also said that once installed, it will continue to do this over the entire lifetime of the product.

MacDonald pointed to a raft of research on the topic to date, and while much of the published literature on the subject is in German, a 2016 conference paper from the BioComposites Centre at Bangor University, Wales found that in laboratory studies sheep wool was “able to absorb a range of harmful chemicals from the indoor environment” including formaldehyde, and that it “buffers indoor VOCs levels to smooth down spikes in concentrations over time.”

Wool is largely composed of keratin proteins, and formaldehyde is able to react with the side chains of keratin amino acids, creating irreversible bonds between the two, sucking formaldehyde out of the air. Research presented

by German academics at the 1999 Indoor Air conference in Edinburgh, for example, found that in experiments wool removed between 80% and 87% of concentration of formaldehyde in a test chamber.

Sheep Wool Insulation is made from 100% pure sheep wool. “Sheep Wool Insulation can be used in walls, floors and ceilings... and is safe, and simple to install,” MacDonald said. See www.sheepwoolinsulation.ie. •

(above) Sheep Wool Insulation installed between timber wall studs.

72 | passivehouseplus.co.uk | issue 30

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To enquire about advertising, contact Jeff Colley on +353 (0)1 2107513 or email jeff@passivehouseplus.ie www.passivehouseplus.co.uk ph+ | marketplace | 73

NORDIC ARCHITECTURE

COLUMN

Reflections on sustainable Nordic architecture It’s no coincidence that Nordic countries are some of the most advanced in the world when it comes to low energy design. Frankly, in such extreme climates, needs must. Three assistant professors of architecture at Aarhus School of Architecture, Sofie Pelsmakers, Urszula Kozminska & Elizabeth Donovan discuss areas where we can learn from our Nordic neighbours – and where the favour might be returned.

T

o meet climate change mitigation targets, higher performing building fabric standards are enforced across Europe. Base principles are set out in the EU’s Energy Performance of Buildings Directive, requiring all new buildings to be nearly zero energy buildings (NZEB) from 2020 (and where publicly funded, since 2019). In response, building industry professionals have included new materials and innovative products, construction methods, energy production and supply systems as part of building design. This was particularly the case in the UK, where the (since abandoned) zero carbon definition emphasised on-site energy production, encouraging the use of additional or innovative technologies and active engineering systems.

While this has led to technological innovations, a downside is that it has generally led to technological ‘add-on’ solutions in favour of further improved fabric energy efficiencies.

In other cases, it has also led to greenwash or to buildings that overly rely on active systems, to the detriment of usability and building performance. Despite the increased focus on reduced operational energy use and associated CO2 emissions (and, more recently, also carbon emission reductions), it can be argued that the construction industry as a whole has been slow to respond to environmental and climatic challenges, often leading to buildings that lack environmental ambition and imagination. More often than not spatial and aesthetic qualities and non-energy related issues are de-prioritised, alienating many in the architectural design profession, and some clients and the public.

As a contrast to these prevailing scenarios, many buildings in the Nordic region quietly respond to society’s climatic and environmental challenges. Moreover, the human-centred approach to the design process has been predominant in several sustainable Nordic projects, though not all.

That is not to say that all new Nordic architecture is inherently sustainable, or that they all avoid ‘bolt-on’ technologies at the expense of other humanistic qualities. However, the Nordic region has a long tradition of carefully crafting spaces to celebrate light and retaining warmth, in response to the harshness of the local climate, such as cold winters, and diminished daylighting during the long

74 | passivehouseplus.co.uk | issue 30

Nordic winters, while also celebrating the long, light summer days.

Alvar Aalto’s 1972 Kunsten Museum (Modern Art) in Aalborg, Denmark. Use of light colours and light-reflecting materials; roof lights specifically designed for different orientations.

Photo: Kozminska, U.

Earlier modernist examples were often inspired by the characteristics of a particular place, such as light, topography, materials, construction methods, history, nature etc. This traditional Nordic contextual, regional and humanistic focus is still at the heart of many contemporary architecture projects, leading to place-and society-specific approaches, often reimagining vernacular traditions and craftsmanship.

In Finland, where average winter temperatures in Helsinki are about -4C, and can drop to below -25C for periods, current urban housing design standards are similar to the passive house standard. Even in milder Denmark (average winter temperatures of about 1C), design standards for housing are also moving towards the passive house standard, while minimum daylighting provision is also legislated for. In Norway, the NZEB standard is comparable with the passive house standard but is measured in CO2 equivalent instead of primary energy. Responding to these harsh climates to keep people warm has been a primary driver of building design.

This has also meant that further consideration of building energy use issues, good building envelope design and detailing has been more integrated and accepted as established

practices in Nordic design and construction traditions for quite some time.

In addition to a focus on energy and thermal comfort, architects are increasingly involved with user engagement (for instance see Vandkunsten’s Lisbjerg Hill), CLT prefabrication methods, and do not tend to neglect spatial quality in favour of good energy performance. It is this capacity for a more holistic approach to sustainability and a more diverse approach to sustainable design that is valued.

However, Nordic architecture can often still fall short in checking that what was designed also works and meets expectations (in other words, post-occupancy evaluations and building performance monitoring).

Feedback processes are even less present than in the UK, though this is slowly changing as the value in going back to projects is becoming apparent. In addition, there is a big potential for knowledge sharing within and outside the region, as well as futureproofing and adaptation for climate change issues such as flood-related risks and increased summer temperatures. This is where the Nordic region is looking to other regions’ approaches, yet so much can be learned from them too. n A fullyreferenced referenced version ofarticle this article is A fully version of this is published online www.passive.ie/nordicdesign online atatwww.passive.ie/nordicdesign

Housing on Lisbjerg Hill by Vandkunsten, Aarhus.

Photo: U. Kozminska

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The next generation of insulations by Pavatex To ensure you have the right speciďŹ cation and technical support, contact; by

Contact NBT T 01844 338338 E info@natural-building.co.uk www.natural-building.co.uk 76 | passivehouseplus.ie | Issue 21