passive house plus issue 5 (irish edition)

editor’s letterate de Selincourt’s article in these pages on passive house at scale reveals asector that’s beginning to break through into the mainstream. Although we werefar from exhaustive, Kate and I did some digging to gain a sense of passive houseactivity on projects other than single houses in Ireland and the UK. Taking multi-unitschemes alone, there are over 300 passive houses built so far in the UK, with

over 1000 more in the pipeline, along with a long list of non-domestic buildings.

Self builds aside, it would be easy to read the comparative lack of forthcoming Irish passive houseprojects as a lack of interest in the world’s leading low energy building standard, but it wouldbe wrong. This lack of activity doesn’t reflect a lack of interest in building passive house atscale – it reflects the lack of construction activity in general. If construction continues to returnto growth, passive house projects will follow.

In fact there’s an argument that once activity returns, market conditions in Ireland should be idealfor passive house. With building regulations dictating that all new Irish homes must be 60%more energy efficient than 2005 standards, developers will quickly discover that there’s littleor no cost difference between building passive and simply aiming for Part L compliance. Thequestion then is whether to choose a proven, robust approach based on sound building science,or to reinvent the wheel and produce buildings that tick compliance boxes but may ultimatelyprove needlessly uncomfortable, costly to heat, and prone to interstitial condensation.

And while Ireland’s regulations set ambitious energy saving targets in the round, the mandatedairtightness target of 7m3/hr/m2 is far too lax, working out roughly ten times leakier than thepassive house standard. Suppose a designer decides to meet compliance using this backstopand some of the poor thermal bridging details shown in the department’s acceptable con-struction details document, and opts for a traditional (and often blocked-up) natural ventilationapproach, while relying heavily on very low fabric U-values, cold bridges excepted. Such anapproach could easily become unhealthy for both occupants and building structure, and couldlead to expensive repair or replacement work.

Perhaps oddly, the surge of interest in passive house in the UK has happened in spite of somethingapproaching a regulatory vacuum. If we take wall U-values as a measure, Ireland has beenahead of the current requirement in England and Wales of 0.30 since 2002 – on paper at least.Unbelievably, the British government has proposed the procurement of carbon credits as partof the solution to produce notionally zero carbon homes, is reviewing whether to scrap theCode for Sustainable Homes, and has proposed a risible 6% carbon reduction under changesto Part L. Yet in spite of such a poor regulatory environment, passive house is growing stronglyin the UK, boosted by the likes of housing associations building passive (and most encouragingly,seeing such positive results that they continue to build passive) and by speculative developerssigning up voluntarily. There can surely be no stronger sign: passive house’s time has come.

Regards,the editor

K

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2012 Business magazine of the year - Irish Magazine Awards

Jeff Colley:

winner - green leader award - Green Awards 2010

Construct Ireland:

winner - green communications award - Green Awards 2010

WINNERGreen Leader Award

WINNERGreen Communications Award

Passive House Plus (Irish edition) is the official magazineof Éasca and the Passive House Association of Ireland

ABC Certified Average Net Circulation of 6,430for the period 01/07/12 to 30/06/13

Issue 5

PUBLISHERS: Temple Media Ltd.PO Box 9688, Blackrock, Co. Dublin, IrelandT: +353 (0)1 2107513 / +353 (0)1 2107512

Email: [email protected]

EDITORIALEDITOR: Jeff ColleyE: [email protected]

DEPUTY EDITOR:Lenny AntonelliE: [email protected]

REPORTER:John HearneE: [email protected]

CONTRIBUTORSKate de Selincourt, Journalist

Pat Barry, IGBCJohn Morehead, Wain Morehead Architects

Kate Ball, Self builder

UK SALESStephen MolyneuxE: [email protected]

READER RESPONSE/ ITDudley ColleyE: [email protected]

ACCOUNTSOisin HartE: [email protected]

ART DIRECTORLauren ColleyE: [email protected]

JUNIOR DESIGNERRex Colley

PRINTING: GPS Colour Graphics, T: +44 (0) 28 9070 2020

www.gpscolour.co.uk

Publisher’s circulation statement: 9,000 copiesof Passive House Plus (Irish edition) are printed anddistributed to the leading figures involved in sustainablebuilding in Ireland including architects; consulting,m&e and building services engineers; developers;builders; energy auditors; renewable energy companies;environmental consultants; county, city and towncouncillors; key local authority personnel; and tonewsagents nationwide via Easons.

Disclaimer: The opinions expressed in PassiveHouse Plus are those of the authors and do notnecessarily reflect the views of the publishers.

Cover: Carlow passive housePhotograph: Ros Kavanagh

cont

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6 NEWS

16 BUILDING OR UPGRADING?

Passive House Plus is here to make your building more sustainable

19 COMMENT

24 INTERNATIONAL

This issue’s selection includes an Estonian modular build that would seeits space heating demand fall by eight if built in Dublin; a family passivehouse on a tight Seattle site; an ultra low energy Italian timber box that actsas a confident, sustainable response to a natural disaster; and a passivecommunity centre in the Austrian Alps that makes stunning use of timber.

32 NEW BUILD

32 Passive architect walks walk with Carlow home

None of the team behind Passive House Plus has the good fortuneto live in a passive house – at least not yet – meaning our promotionof passive house comes with more than a hint of “Do as I say,not as I do”. That’s emphatically not the case with certified passivehouse designer Helena Fitzgerald, who chose to practice whatshe preaches with her own home, to stunning effect.

38 Irish whiskey distillery puts fabric first

Passive house is all about using tiny amounts of energy to delivermaximum comfort for those living and working in buildings thatmeet the standard. So why did Wain Morehead Architects turnto their passive house knowhow when designing a whiskey distillerythat won’t have any occupants?

44 Co Down passive house built for under £200,000

As passive house moves into the mainstream, construction costsare bound to keep coming down. One recent self build showsthat low cost passive house needn’t be a distant aspiration –it’s achievable now.

50 Northwest facing home shows passive flexibility

Intent on making the most of spectacular views to the northwest,Rob Davies and Amy Staniforth’s ecological self-build showsthat passive house can overcome orientations that turn theirback on the sun.

56 Social scheme finds value in passive

Broadland’s Housing Association’s first certified passive schemein Norfolk is a significant step on one social developer’s journeytowards social housing fit for the 21st century.

62 UPGRADE

62 Dublin 4 home reborn with Enerphit upgrade

In spite of a dauntingly complex and crumbling existing building,a detached house in Donnybrook has been modernised to becomeIreland’s 2nd certified Enerphit building.

70 Derbyshire upgrade blitzes Enerphit target

Hitting the Enerphit standard can be challenging for even themost seasoned passive house specialist, so what chances didKate and Geoff Ball’s semi-d have when the architect and builderhad no passive experience?

74 INSIGHT

Passive house goes large

With over 300 passive houses built to date in multi-unit schemes and athousand more on the way – along with major non-domestic builds –increasingnumbers of British & Irish developers are going passive. But how will thesector cope with upscaling, and will the most cost-conscious developersbe attracted to the standard?

80 GLOSSARY

Perplexed by all this talk of U-values, blower door tests and embodied energy?Our sustainable building glossary will help you get to grips with the keyterminology.

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passivehouse+ | Issue 5

News

Ireland could become passivehouse leader, conference hears

Former president of the European parliamentPat Cox has said that with political will Irelandcould become a world leader in the passive housestandard, and stated it was a “crime againstourselves” that we built substandard housingduring the property bubble when we could havebuilt to the world’s leading low energy standardinstead.

Cox was speaking at this year’s See the Lightconference, which was organised by the PassiveHouse Association of Ireland and held at DublinInstitute of Technology on Friday 25 October.

The event’s keynote speaker, Passive HouseInstitute founder Wolfgang Feist, presented proj-ects from across the globe, including a passiveskyscraper built on the site of a former Opecbuilding in Vienna. “We can substitute oil by usingthe brain,” Feist said. He also announced thatthe first passive house window certified for usein arctic climates would soon be available.

He also said: “There is no performance gapwith a passive house, because a passive houseis already defined by the performance.”

Speaking to Passive House Plus before theevent, Feist called on Irish homeowners to aimfor energy upgrades of at least 75% when up-grading their homes. “"If you're going to theeffort of upgrading your home, do it right, andthe extra investment for doing it right is quitesmall.” For an in-depth interview with Feistfrom the conference, see page 19.

The conference’s main session was chaired by

Irish Times environment editor Frank McDonald,who pointed out that nobody from either thedepartments of environment or energy were inattendance on the day (though representativesof SEAI were).

Speaking at the conclusion of proceedings,DIT president Brian Norton said that buildingson the institute’s new Grangegorman campuswould exceed the passive house standard.

Earlier in the day, Enterprise Ireland’s PaulButler said that the Irish economy would sig-nificantly benefit from the construction indus-try implementing the passive house standard.He said moving to the standard would helpIreland tap into lucrative export markets.

Speaking to Passive House Plus before theconference, Butler said: “Moving our buildingstock to the passive house standard wouldnot alone create significant jobs in constructionand retrofit, but in the production of the ma-terials and products used. In embracing pas-sive and low energy build technologies andsystems, Ireland would be in a strong positionto export products, build systems and skills asthe problems that Ireland has are duplicatedaround the world.”

The conference lineup featured the presentationof a numerous low energy building projects,including the Bord Gáis Network Services Centrein Dublin, as well as sessions on the perform-ance gap and post occupancy evaluation.

During the latter session, University of Ulster

researcher Peter Keig stated that he believed theonly way it was possible to reach 80% carbonreductions in the building stock was to decar-bonise electricity.

Speaking during a session titled “What now forthe construction industry,” Pat Barry of theIrish Green Building Council said that Europewas now beginning to look at the whole build-ing life cycle energy consumption.

He said that because there is little Ireland cando about its agricultural emissions, the focusof reductions would have to be on transportand buildings. He said that within the next fewyears it should be possible to calculate the fullembodied energy of buildings.

Speaking during the same session, Mel O’Reillyof the Master Builders and Contractors Associationand MDY Construction – who built a certifiedpassive extension to Glen Ashling Nursing Home,Co Kildare – spoke about how a negative rep-utation still persisted around the Irish con-struction sector, and said there was declininginterest in construction courses among students.

But he said that while the level of constructionreflects the wider state of economic activity, itwas also the case that infrastructure had tobe built in order to attract business.

(above) former European Parliament president PatCox addressing the See the Light 2013 conference;Passive House Institute founder Prof Wolfgang Feisttalks to Passive House Academy founder Tomás O’Learyat the event

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News

IEA: energy efficiency isworld’s “first fuel”Energy efficiency is the world’s ‘first fuel’, andbuildings are the sector with the largest untappedeconomic energy efficiency potential – at a highof 80% by 2035 – according to the InternationalEnergy Agency.

The findings were raised by IEA executive di-rector Maria van der Hoeven, and relate to theIEA’s Energy Efficiency Market Report andWorld Energy Outlook 2013.

Far from its previous ‘hidden’ status, energyefficiency is acquiring a stronger visibility asits real estimated contribution towards energysecurity and public finances are increasinglyquantified. According to IEA calculations, 11 ofthe IEA member states made energy savingsequal to $420 billion (€310bn) between 2005and 2010, a quantity higher than any other singlefuel source. In relation to increasing energy prices,the IEA estimates that the rising energy demandcould be decreased from 45% to 33% if newenergy efficiency policies were to be put in place.

Unlocking the huge energy efficiency potentialin the building stock is recognised yet again inthis year’s World Energy Outlook as the keystepping stone to achieving these energy sav-ings, both through current and new policies.

The WEO 2013 estimates that “The maindriver behind the energy savings in Europe isthe implementation of the EU Energy EfficiencyDirective. The main components that reducefinal energy consumption are the energy effi-ciency obligation scheme, together with the

renovation of the building stock (�)”

Article 4 of the EED requires member statesto draw up a long-term strategy for mobilisinginvestment in the energy efficient renovationof their building stock. The deadline for sub-mission is April 2014.

“This will be a key opportunity for member statesto elaborate coherent, long-term strategies fortheir building stock, which looks at the full build-ing in a holistic manner, rather than piece-meal

individual measures”, explained Adrian Joyce,secretary general of EuroACE. “Maria van derHoeven describes energy efficiency as the onlyfuel that simultaneously meets economic, en-ergy security and environmental objectives –member states should drill the deepest wellcontaining this first fuel – energy efficientbuildings.”

(above) IEA executive director Maria van der Hoevenhas described energy efficiency as the world’s “first fuel”

The government’s decision to retain grantfunding for energy upgrades while introducingtax incentives for home upgrades will make en-ergy retrofitting more appealing than ever, theSustainable Energy Authority of Ireland has said.

An allocation of €57m provided by governmentmeans that Better Energy Homes will remainopen for grant applications throughout 2014.The new Home Renovation Incentive offershomeowners tax credits worth up to €4,050 forhome upgrade work. Although homeownersare entitled to avail of grants and the tax in-centive, double counting – where grants andtax credits are claimed for the same measures– is prohibited. The tax incentive will howevermean that homeowners can aim for deeper

energy upgrades – for instance using grants tosubsidise insulation costs, and using the taxincentive to subsidise measures such as triple-glazing, airtightness work, renewable heatingand electricity generation, and MVHR or de-mand-controlled ventilation.

According to SEAI chief executive Dr BrianMotherway: “The continuation of the BetterEnergy grants for another year is a great en-dorsement by government of the many benefitsof energy retrofitting. We’re also really pleasedthat homeowners can qualify for both incentivesmeaning home energy upgrades have neverbeen more affordable. Householders will benefitdirectly from more comfortable homes and lowerenergy bills, while thousands of jobs are sup-

ported in the construction sector.”

SEAI recently marked the milestone of 250,000homes upgraded in Ireland through the BetterEnergy schemes. Free home energy upgradeshave been completed in 100,000 vulnerablehomes through the Better Energy Warmer HomesScheme. A further 150,000 homeowners haveavailed of Better Energy Homes grants for in-sulation and heating upgrades.

Energy minister Pat Rabbitte said: “Home energyretrofit has been very successful to date and theseincentives provide further impetus to household-ers to carry out works. Their investment will berewarded through long term energy cost savingsand tax credits for qualifying work.”

Grants and tax incentives offer deepenergy upgrade hope

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News

CPD accredited online passive housetutorials launched

A new online passive house tutorial video serieshas just been launched by Energyquarter.The series is hosted by Tomás O’Leary fromthe Passive House Academy, Passive HouseInstitute accredited trainers.

Passive house is fast becoming the leadingenergy efficiency and comfort standard acrossthe world for all building types. According toEnergyquarter’s Estelle Cotter, over 40,000passive house buildings have been built globallyincluding schools, offices, supermarkets and

apartments.

“This is a must-view series for architects, en-gineers, tradespersons, self-builders, plannersand anybody who wants to know more aboutthis super energy efficient building method,”said Energyquarter’s Estelle Cotter.

The series includes in-depth coverage of PHPP,energy balancing, passive house certificationcriteria, insulation and airtightness levels, U-value and airtightness calculations, blower door

tests, windows, solar gain, and much more.

Contribution to CPD learning is a key featureof this tutorial series. With accreditation fromthe Royal Institute of the Architects of Ireland(RIAI) and the American Institute of Architects(AIA) in the US, participants can test their knowl-edge with the multiple-choice passive housequiz and gain valuable CPD or continuing ed-ucation points.

Passive House Plus editor Jeff Colley said:“Energyquarter's passive house tutorial se-ries sheds real light on passive house design,including practical advice on how to achievethe passive house standard. People who watchthese tutorials will gain invaluable knowledgein robust, genuinely low energy building. Thetutorials achieve something we aspire to inour journalism: they make technical subjectmatter accessible, but without dumbing down.”

The tutorials employ various visual aids such asfull-scale passive house construction models andpractical demonstrations to highlight key messages.A free preview of the passive house tutorials isavailable online at www.energyquarter.com

(above) Passive House Academy founder Tomás O’Learydescribes the PHPP software in an EnergyquarterCPD approved tutorial

Isover Ireland has recently launched a new rangeof products to their airtightness and moisturecontrol range. According to Isover, the newVario Xtra System is a “next generation solution,combining optimum performance with fast andefficient installation”. The new system consistsof Vario Xtra Safe intelligent membrane andVario Xtra Fix fixative strip and can be used inconjunction with all other existing Vario ac-cessory products.

Vario Xtra Safe membrane is an intelligent mem-brane for greater safety, offering a higher vari-ability for optimum protection from moisture.With an Sd value ranging from 0.3 to 20 m, Isoversaid that Xtra Safe has the best variabilitycurrently available on the Irish market, andthat it is particularly suited to our climate withits high humidity levels.

This means it is designed to tackle a wide varietyof applications and deal with extremes in tem-peratures much more effectively particularlywith our changeable climate, including recentcold snaps in winter and higher than normalsummer temperatures.

The membrane can be simply and quickly installed

by just one installer, thanks to its “innovativefleece material which adheres to the Xtra Fixtape, meaning that the membrane can be easilyremoved and replaced during installation withno staples required”. The airtight barrier doesnot need to be punctured with staples.

The Vario Xtra range offers a wide variety ofefficient application solutions from pitched roofsand timber frame constructions to flat roofs. Thecompany said that Vario Xtra Safe allows installersto fully fill the insulation space between rafterswith no need for an air gap. This is particularly

beneficial in cases where it can be challengingto provide ventilation in non-breathable pitchedor flat roofs, the company said.

“The Vario Xtra range offers groundbreakingcapability bringing intelligent airtightness mem-branes to a whole new level,” said Fintan Smyth,building physics manager with Isover Saint-Gobain.

(above) Isover’s Xtra Fix tape enables membranesto be installed without being punctured by staples

Isover launch Vario Xtra system


News

Ecocem launches carbon reductionroadmap for cement industryEcocem Ireland has released a consultationdocument outlining a carbon reduction roadmapfor the cement and concrete sector. The roadmapis a response to the government’s request forinput into formulating a national roadmap in2014 which will bring Ireland into line with theEU target to reduce CO2 emissions by 85%, andtransition to a low-carbon economy by 2050.

The cement and concrete sector is failing tomeet the EU 2050 carbon roadmap targets, andEcocem said that emissions are far too highand will remain so with current technologiesand existing national policies. The companysaid that available green technology is un-derutilised, and that increased R&D will benecessary to prepare for radical technical in-novation to ensure the sector’s survival in a carbonconstrained world.

Donal O’Riain, managing director of Ecocemsaid: “The cement and concrete sector is thelargest manufacturing source of CO2 emissionsin Ireland. Innovation, new technologies andeffective public policy are essential to changethis and to help decarbonise this sector.”

He added: “Our aim with this consultation paperis to seek industry input into a final roadmapwhich will go to government in early 2014, withspecific recommendations on how to achievethe low-cost transition to a low-carbon econ-omy in Ireland, while creating new and sus-tainable jobs. Radical change is unavoidableand the solution requires the participation ofall stakeholders in the construction industry.”

The transition to a low-carbon cement and con-crete industry will be a major source of newjobs in Ireland, according to Ecocem. The com-pany estimates 600 to 1,200 new jobs can resultfrom the manufacture of low-carbon concretefor export markets within three to five years,

while harmful environmental and health ef-fects of emissions can be mitigated.

(l-r) climate scientist Prof John Sweeney of NUIMaynooth pictured with Ecocem MD Donal O’Riainat the carbon reduction roadmap launch

Polytherm heating systems has acquired ex-clusive all-Ireland distribution rights for spe-cialist German radiant heating and coolingmanufacturer Frenger BV.

Using the principle of radiant heat, radiant ceilingsystems heat and cool buildings in a mannerthat is both “cosy and efficient,” said Polythermgeneral manager Kevin Devine.

These systems can be used in any room up to30m high, from production halls, warehouses,schools, hospitals and offices to exhibition roomsand showrooms. Individually manufactured andtailored to the requirements of each property,Frenger ceiling-mounted heating and coolingsystems can make a significant contribution tolowering a company’s energy costs, Devine said.

“Savings of up to 50% are achievable with radiantceiling systems when compared to traditionalforced air systems. With radiation outputs of upto and including 81%, Frenger was our top targetin terms of a radiant heating panel supplier,”

he added.

The Eco Evo Plus panel has installation ap-plication in a broad range of buildings includingsports halls, logistics centres, manufacturinghalls, warehousing and schools, and achieves aradiation output of 81% due to its innovativepatented construction which minimises con-vection losses, Devine said, adding that thesystem has already been installed locally inIreland with very favourable results.

Frenger also produce radiant ceiling tiles (HKEModel) that can be integrated within a suspendedceiling and as such are ideal for use in offices,operating theatres, laboratories and classrooms.

EU Energy minister Günther Oettinger recentlyvisited the Frenger HQ in Frankfurt, which isone of only a handful of industrial buildings tobe classified as energy plus. The 6,000 squaremetre building only consumes 10kWh/m2, andfeatures excellent insulation and airtightness,high efficiency radiant panels for heating and

cooling, and ground source heat pumps.

(above) Frenger’s radiant ceiling systems have a widerange of applications including sports halls and manyother building types

Polytherm & Frenger sign exclusive partnership

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News

Best-in-test Nibe heatpumps now "even moreefficient"Swedish heat pump manufacturer Nibe hasannounced that its entire heat pump rangehas been equipped with new features thatmake them more efficient.

Paul O’Donnell of Unipipe, distributors forNibe in Ireland, told Passive House Plus thatthe brine and heating medium pumps acrossall units are now controlled by internal soft-ware rather than set manually by the installer.This means the heat pump can adapt to real-time conditions and maximise efficiency.

“It automatically adjusts the settings to theideal flow rate, so it’s always using the leastamount of energy,” he said. “The end user isgetting an enhanced product at no extra cost.”

O’Donnell said this means new Nibe heat pumpsare now even more efficient than those thatcame out top in Swedish Energy Agency testsperformed last year.

Nibe came out on top in recent (2012) SwedishEnergy Agency tests performed on both groundsource heat pumps and speed-controlled ex-haust air heat pumps. All major brands on theSwedish market were included in the tests.

The Nibe F1245 was awarded highest points

in 14 of the 25 performance areas in the groundsource heat pump test.

The F1245 delivered the greatest energy savingsof all the brands tested, and was rated best in14 of the 25 performance areas examined. Itwas also the only product whose coefficient ofperformance was great than 5.0 for the buildingstested.

The F1245 also had the greatest hot watercapacity of all the products tested at 258 litres,and was also the most compact model.

Meanwhile, Nibe’s F750 speed-controlled ex-haust air heat pump received the best ratingfor 15 of the 20 characteristics tested.

Speed control means that the heat pump au-tomatically and continuously adjusts to the re-quirements of the home, helping to save moreenergy.

All the company’s heat pumps now feature NibeUplink software and internet monitoring too.

(right) the Nibe F1245 heat pump, awarded highestpoints in 14 of 25 performance areas in a SwedishEnergy Agency test on ground source heat pumps

The Department of the Environment is con-sidering creating legislation to mandate latentdefect insurance for housing construction, PassiveHouse Plus has learned.

According to a source in the department anylegislation to introduce latent defect insurancewould not involve amending the forthcomingBuilding Control (Amendment) Regulations,which are due to come into effect in March.

Passive House Plus editor Jeff Colley has ad-vocated the role that latent defect insurancecould play in providing consumer protection inthe event of building failure since 2007, initiallyas a proposal to regulate the domestic wastewatertreatment market. In 2008 Colley put a proposal tothe Sustainable Energy Authority of Ireland to makelatent defect insurance mandatory for grant

funded home energy upgrade projects prior tothe launch of the Home Energy Saving scheme.

The amended building control regulations havebeen designed to prevent non-compliancewith building regulations, and will usher in anumber of changes. The designer of a buildingwill be required to submit compliance drawingsand documentation – including Deap calculationsshowing how the proposed building will meetthe 60% energy and carbon reductions underPart L – to local building control authorities atcommencement notice stage. Assigned certi-fiers – including registered architects, engineersor surveyors – will then be obliged to inspect thebuilding at key stages during construction. Manda-tory certificates of compliance must then be signedby the certifier and builder and submitted to thebuilding control authority upon completion.

There has been widespread concern in thearchitectural community that the new regula-tions will place an unreasonable burden onarchitects – with prominent architects such asEoin O’Cofaigh arguing that architects or en-gineers signing the new certificates would riskcommitting “professional suicide”. O’Cofaighand fellow former RIAI president Michael Collinscommissioned a legal opinion on the matter fromDenis McDonald SC, who concluded that theregulations place “significant additional re-sponsibilities upon architects [�]“including aresponsibility to certify the work of others”, andtherefore may lead to a substantial increasein claims against architects. It’s unclear whetherlegislation to mandate latent defect insurancewould reduce the risks facing certifiers if theamendments to the building control regulationsremain unchanged.

Government considers legislating forlatent defect insurance


News

Smet renders high profile building projectsRenders supplied by Smet Building Productshave been used on a variety of high profile build-ing projects across the country recently.

Through-coloured, low maintenance, OnexitUniversal Render has been selected as thefaçade solution for many new developments,retrofit and refurbishment projects across Ire-land and the UK, including Delgany Village inCo Wicklow, ecological architects Solearth’sAirfield Project in Dundrum, Aughrim GAA Club-house in Wicklow and Our Lady’s Hospital inCrumlin.

Meanwhile, SHG Bauprotec 850 M lightweightlime cement render has been used to rendernew and refurbished poroton-built Lidl stores.SHG Bauproclac KAP is a factory produced nat-ural hydraulic lime plaster specially designedfor hand and machine application.

Spray applied SHG Bauprocalc KAP has beenselected as the façade solution for numerousrenovation projects, such as Mardyke Street,Cork City; the Valhalla Project in Dublin; andmany old farm houses and town houses acrossthe nation.

According to Smet, this product’s unique prop-erties such as high breathability, sustainability,and a special composition which allows constanthygrometric exchange between the substrateand the environment, are key drivers in theselection of this façade system.

The company said that its products are selectedfor a wide variety of reasons: low weight, lowdensity, low thermal conductivity, high yield

and “superior technical back up”.

Smet supply a wide variety of professional rendersystems designed for all building systems in-

cluding traditional concrete block, brick, porotonbuilding systems, insulated concrete formwork(ICF), timber frame building systems, retrofit, andhistoric restoration and conservation builds.

Ecological Building Systems won the awardsfor best exterior building product and best in-terior building product at the RIAI ArchitectureExpo 2013 show. The company’s Passive EcoWall concept won best exterior building productwhile the Smart Six Insulation Expander systemwon best interior building product.

Passive Eco Wall is designed to provide a com-plete low energy, diffusion open building con-cept based on passive house principles. Itutilises natural insulation materials suppliedby Ecological Building Systems in Ireland andthe UK, as well as the Pro Clima intelligent air-tightness system. A number of certified passivehouse buildings have already been constructedbased on this concept.

The Smart Insulation Xpander System (SmartSix) is designed to provide greater flexibilityin the thermal refurbishment of existing buildings.The system can also be utilised in new buildings.Smart Six creates additional insulation spacefor roofs, walls and floors in an “effective, eco-nomical and safe manner”. The system can beapplied either internally or externally. The SmartSix system is designed to allow installers moreefficiently align rafters or joists and at the same

time significantly increase insulation thicknessesin a cost-effective manner.

Ecological Building Systems engineer NiallCrosson said: “We are delighted to have wonsuch prestigious awards. The market demandsmore innovative solutions to deliver passivehouse levels of performance and also to tacklea number of the complexities which can arisein the retrofitting of existing buildings. Our Pas-sive Eco Wall and Smart Six solutions bothprovide innovative practical solutions for bothmarkets.”

Ecological Building Systems has pioneeredenvironmental and sustainable building productsolutions for over a decade, gaining the soleagency in Ireland and the UK for Pro Clima,the award winning intelligent airtight and windtightbuilding system. The company also supply arange of natural insulations such as Thermo Hempand Gutex wood fibreboards.

(pictured) Ecological Building Systems’ Niall Crosson(centre) accepts Architecture Expo awards from judgesGary Mongey of Box Architecture (left) and Knut Klimmekof Klimmek Henderson Furniture (right); the anatomyof the Passive Eco Wall system

Ecological Building Systems wins two RIAI awards

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News

Irish airtightness expertise gainingrecognition abroad

Irish airtightness expertise is beginning to spreadinternationally, according to Gavin O’Sé of Green-build and Mark Shirley of 2eva.ie, two of thecountry’s leading airtightness testers.

Shirley told Passive House Plus that he recentlyperformed an airtightness test for a client inCatania, Sicily, who was building the island’sfirst certified passive house.

“There are no airtightness testers in Sicily, andhe couldn’t get anyone to come from the Italianmainland,” said Shirley, who met the client ata passive house trainers course in Germany.

When Mark arrived at the house in Sicilly, hefound the client clutching a copy of a documentGavin O’Sé published on his website, titled Guide-lines for Blower Door Testing of Passive Houses.

“He used Gavin’s information as part of his duediligence to make sure that the house was con-structed in the appropriate airtight manner,” Marksaid.

On foot of his investment and experience theclient, Carmelo Sapienza of Sapienza partners,has started working on a number of other passivehouse projects in Sicily.

Mark Shirley also has clients in the UK, whileGavin O’Sé told Passive House Plus he has re-ceived theoretical queries on his blower doorguidelines from those who have downloadedthe document in the UK, the US and NewZealand.

Gavin said he published the document due to theexistence of slightly different blower door testprocedures in different countries, “so that every-body who’s doing blower door testing for passivehouse would kind of have the same under-standing.”

The news is particularly encouraging as Irelandseeks to become one of the world’s leading coun-tries for the export of passive house products andexpertise.

(above) this passive house in Catania, Sicily has beeninfluenced by Irish airtightness experts Gavin O’Séand Mark Shirley

Intelligent building automation will be one ofthe big themes at this year’s Light and Buildingtrade fair, which takes place from 30 March to 4April 2014 in Frankfurt. Around 2,300 compa-nies will present the latest products and inno-vations for the lighting, electrical engineering,home and building automation, and constructionsoftware sectors.

The last Light and Building fair in 2012 set avisitor record for the fair and exhibition sector,with 196,000 visitors coming to see the hugerange of products and services on show.

At next year’s event, international manufacturerswill present fully-developed building automa-tion technologies and software solutions.

The different ways in which networked buildingscommunicate with the smart grid and how theygenerate, store and consume energy will beaddressed at a special show entitled ‘Smartpowered building – your building in the smartgrid’. Real installations in live operation willshow how networked buildings can generate,store, distribute and use energy locally.

This special show is an initiative of Messe Frank-

furt with the support of the German Associa-tion of the Electrical and Electronics Industry.

In addition to the special show, the E-House ofthe Central Association of the German Electricaland Information Technology Trades will demon-strate the opportunities offered by intelligent build-

ings with regard to energy efficiency, comfort, safetyand security.

(above) innovative approaches to energy production,consumption and demand reduction will feature heavilyat Light and Building

Intelligent building systems at 2014 Light and Building fair


News

Historic Wexford guesthouse switches toair source heat pumps

Two new air source heat pumps should provetheir worth in energy savings to the owners ofhistoric Ballinkeele House in Co Wexford. Tohelp combat high energy bills, Val and LauraMaher decided to install two Toshiba 16kWheat pumps to replace their old oil boiler earlierin the year.

The Mahers run their 1840s home as a guest-house, but found that it was consuming roughly17,500 litres of oil per year, at a cost of €14,000.

In February, AC Heating installed the twoToshiba heat pumps, which are designed tocover about 95% of the house’s space heat-ing and hot water demands. The oil boiler hasbeen in left in place as a back-up.

The new heat pumps have been running forabout nine months, and have used about 18,000kWh of electricity since, at a cost of roughly€3,000. The couple also insulated their roofat the same time as the new heating system

was installed.

Laura told Passive House Plus that they are happywith the system so far, though they have ob-viously yet to experience a full winter with it.

“It’s early days, but there’s no doubt the houseis more comfortable,” she said.

“We used to turn the heating off in the mainhouse when we were closed or didn't haveguests in the winter. To bring the house up toa comfortable temperature from cold, theheating would have to be on constantly for acouple of days. With the heat pumps, and thetemperature sensors that were installed in thefour zones of the house, we can maintain aconstant temperature making it much quickerto heat and more efficient."

“It’s something we’re learning to tweak to ourchanging needs and we like the flexibility of it.The controls are web-based, so we can just

connect to it and change the settings from ourliving room couch.”

(below) AC Heating has installed two new Toshibaair source heat pumps at Ballinkeele House, CoWexford (above)

The Heat Pump Association of Ireland haswelcomed the publication of the latest BRGBuilding Solutions report on EU energy policyand legislation, which projects a bright futurefor heat pump technology.

The report projects that electric heating in-cluding heat pumps is “likely to be a long termwinner, especially within the context of de-

carbonised power generation”.

This contradicts sharply with the report’s pro-jections for oil, which it said is “likely to fadeaway as fuel for heating in any form”. The reportalso projects a bright future for solar heatingand heat recovery ventilation.

The report points to Ireland’s commitment to

achieving 40% renewable electricity generation by2020, and to the planned closure of power plantsthat burn heavy foil at Great Island and Tarbert.

“Basically what we can infer from that is thatwith 40% renewable energy on the grid in futureit further enforces the case for heat pumps asa clean heating source,” a Heat Pump Associationspokesperson told Passive House Plus.

Heat pump association welcomesenergy policy report

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News

PV Tech gains big projects in the west

Solar energy experts PV Tech have recentlycompleted photovoltaic installations at a numberof high profile buildings in counties Galwayand Clare.

The company installed 3.5kW and 5kW PVarrays respectively at the new Doughiska primaryand secondary schools, both on the east sideof Galway City. These installations were of QCells Q Pro polycrystalline arrays.

The company also installed a 4kW flat roof QCells Q Peak monocrystalline array at GalwayCounty Hall, as part of a larger upgrade of thebuilding that saw the authority replace its oldoil boilers with gas.

“They’re looking at it from the point of view oftrialling it and maybe putting more PV in at a

later date,” said Mike O’Rourke of PV Tech.

PV Tech has also installed two PV systems at thehome of the East Clare Community Co-Op in Scariff.The larger of these system (5kWp) is a semi-transparent array of PV panels over a conserva-tory / sunspace. The system is designed to helpprevent overheating of the sun space in summerby providing some shade while generatingelectricity with the captured light. The secondsystem (1.9kWp), over the slate roof, utilises theQ Cells Q Peak monocrystalline PV modules.

O’Rourke told Passive House Plus that the PVmodules are made semi-transparent by allowingextra space between the PV cells and encapsulat-ing them in a glass/glass laminate module withfully transparent encapsulating material. Theseparticular modules are 33% transparent.

“You’re spreading the cells out a bit more andusing a transparent material to let the light through,”he said. "Whereas with a standard panel every-thing is together to get as many cells as youcan per square metre of panel.”

While this means each square metre of panelproduces less electricity, O’Rourke said architectsare often attracted to this system for aestheticor partial shading purposes.

Each of these systems has been installed withStecaGrid Coolcept grid tie inverters which nowoffer live internet monitoring of the PV systemas standard.

(above) the 4Kw solar PV array installed by PV Techon the roof of Galway County Hall

Munster Joinery celebrates its 40th year in businessthis year. The company is fully family owned andstill operates from the original factory site out-side the village of Ballydesmond, Co Cork. Thefirm said that it has always maintained closecontact with its customer base and supportsthe local economy by providing employmentin the region.

The company said that it has grown year onyear by building on its strengths – "quality, deliveryand service". Founded in 1973 the companyoperates in Ireland, Northern Ireland and theUK, and has a 910,000 square foot productionfacility in Ballydesmond, Co Cork. In 1998 a230,000 square foot manufacturing plant wasset up in Warwickshire in the UK. The companycurrently employs 1,700 people.

Munster Joinery said it looks to the future by

using innovative techniques to streamline itsprocesses and to develop products to meetdiverse customer requirements. Energy efficiencyplays a key role both in operational decisionsand product design.

Two wind turbines play a vital role in providing4.2 MW of electrical energy for day to day man-ufacturing. A combined heat and power plantuses all timber offcuts and extracted saw dustto produce 2.8MW electrical and thermal energy.A determinedly green waste management pol-icy ensures opportunities for recyling are fullyexploited. All of this is designed to ensure thatproducts are delivered to site with low embodiedcarbon.

To date five Munster Joinery product rangeshave been certified as passive house suitablecomponents by the Passive House Institute in

Germany.

(above) then and now: Munster Joinery’s Ballydesmondproduction facility has grown significantly since 1973

Munster Joinery turns 40


News

Partel bring Ampack airtightness system to IrelandGalway-based company Partel, specialists in lowenergy building supplies, became the exclusiveIreland and UK agent for Swiss airtightnessproduct manufacturer Ampack last year.

“For 60 years now, Ampack has been developingsystems and solutions that safely and professionallyresolve all the problems associated with pro-tecting the building envelope,” said Partel’sHugh Whiriskey.

“An airtight and wind tight building envelopecan only be ensured if the products are installedcorrectly,” Whiriskey said. “This puts professionaltradesmen in a tricky situation: new designsand construction products are constantly flood-ing the market making it more and more difficultfor contractors to maintain an overview and be-come skilled at installing the products correctly.”

But Whiriskey said that customers who chooseAmpack can expect to benefit from compre-hensive building expertise, including technicaladvice, a phone hotline, a ten year warrantyand customer training.

During its training courses, participants learn howto use Ampack products safely and are pro-vided with the knowledge to answer the mostimportant questions regarding safety standards,air and wind tightness, and application engineering.

Tradesmen can claim on Ampack’s comprehensivewarranty at any time within ten years of buyingthe product from a specialist retailer, providedthat the terms and conditions are met. In anemergency, the claim will be processed quicklyand competently by Ampack’s technical advisers.

Ampack cover the replacement materials plusthe removal and installation costs, as well as anysubsequent damages.

(above) the Ampack airtightness system, available inIreland via Partel

Are you designing, building or pricing a sustainable building?Whether it's an energy upgrade of a small house, or you're lookingto achieve high green standards with a new home, office or factory,Passive House Plus can help.

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Wolfgang Feist is a founder and director of thePassive House Institute, one of the originators ofthe passive house concept, and a professor atInnsbruck University. In his Twitter profile, hedescribes himself as a “curious physicist withinterests in sustainability, energy efficiencyespecially”.

Passive House Plus deputy editor Lenny Antonellisat down for a chat with him after his keynotespeech at this year’s See The Light conference,organised by the Passive House Association ofIreland. Like Prof Feist this magazine has alwaysbeen a big advocate of a scientific, evidence-basedapproach to building design, so it was no surprisethat we found ourselves talking about this fromthe outset�

Wolfgang: It's very important to do things in ascientific way. Even if you find out things you don'tlike, it's good to learn the truth. It’s always betterto "look the facts into the eye", as we say inGerman, because it doesn't help to believe insomething which isn't true.

Lenny: That's something I wanted to ask you

about. We get contacted by people who have

very (to use one of Wolfgang’s own terms)

mythological ideas about what sustainable

building is: whether it's people who want to

promote something like feng shui to all sorts�

W: It’s not our main task to fight such movements,as long as they are not against the rationalthings to do. It's very difficult to move people

if they believe in something.

L: Because they’re not thinking rationally in

the first place, so how do you argue with them?

W: It’s very difficult and I wouldn't invest too muchtime trying. What is important is for yourselfto follow a true scientific approach, somethingthe Passive House Plus magazine certainly does.You follow a scientific approach, meaning thatif there are new insights, you might change yourevaluation. That’s just the nature of science. Thisis the way to go, and it brings us the best results.

L: You said when you were speaking that

the most resistance to pushing passive

house or the wider energy efficiency agenda

is at national government level, and not

European or local level.

W: Yes, this is surprising. The European Com-mission is completely behind the idea, it’s veryinteresting.

I have a theory why it’s so much more difficulton the national level: because lobbyists con-centrate on that level. There are powerful lob-byists who want to sell their products, and theyhave a huge influence on the national level, whichwas the most important political level historically.

L: Are the European Commission at a level

so far above national politics that�

W: No surely not – but they are not so important

(laughs)! That's one of the reasons. And thesecond reason is, we have lobbyists in France,we have lobbyists in Germany, we have lobbyistsin the UK, but they have different interests. Sothey can't reach a common lobbyists programmefor Brussels. And that's where a rational approachhas a chance.

We have seen the car industry influencing Ger-many, and the Germans stopping a very goodproposal from the European Commission [tolimit CO2 emissions from cars], because of lob-bying from the specific interests of some na-tional automotive industries� I think the discussionwe just had with Mr Pat Cox [former presidentof the European Parliament] was very interesting.Coming from a European Union level, he seesthings exactly the same way.

So that’s the way it will work, we can work togetherwith the European Union to promote regionaldevelopment and bypass national interest groups.

L: Based on today, and on your own travels

around Europe, where do you think Ireland

is in terms of momentum for passive house

and for energy efficiency?

W: Seeing the momentum in this room, it’s veryadvanced. The momentum is very concreteand there are really good examples. I can alsotell by your journal. So yes, you are very far andyou are not facing a lot of resistance. Theremight be some resistance, but not the kindI’ve seen in Austria. �

INTERVIEW:Passive house pioneer, Prof Wolfgang FeistWe spoke to the Passive House Institute founder about the scientific method, political campaigning and theinstitute’s goals for the future after his keynote address at this year’s See The Light conference in Dublin

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L: From whom?

W: Well, from some big industries. Pushing reg-ulations, making passive house mandatorytoo fast or even just talking about making itmandatory, brings up resistance. That waswhat happened in Austria. Most of the time,lobbyists ignore such developments, but whenit comes to discussions about making it manda-tory, they begin fighting. That’s very danger-ous for the passive house movement whichisn’t strong enough yet to fight big industrylobbyists. So the best path is to work togetherwith those who want to make it happen. Whatyou can fight for is incentives — for improvedconstruction, or for better retrofits.

I just talked with Mr Kraft, who used to have aleading position within the German financinginstitution KfW. They gave out incentives forenergy retrofitting of buildings, and still do sotoday. He told me about a study from Prognos,a big economic institution in Basel, which proveswhat I’ve been saying all along but haven’tbeen able to prove thus far — that the moneythe Germany government spends on theseincentives is more than compensated for bythe return in taxes [raised from the retrofit activity].So this is a really good deal for the government.

L: Maybe it’s not the case elsewhere in Europe,

but certainly here in Ireland, anytime an ar-

gument is made in regards to economic

recovery that if you invest a euro you’ll get

three euro back, they never seem interested

in listening to that long term argument�

W: I know, we have had the same discussionsin Germany. But with this paper from Prognos,you can really prove it. Everybody talks aboutthe economic benefits of investment in retro-fit, but you have to do the research in a properway. Unfortunately, it is often done incorrectly.

Of course you have to be honest. The statepartially funds these extra investments in en-ergy efficiency. Some private money is addedto it, so the state will be able to recover someof the money spent through taxes. But on theother side, building owners and residents spendless money on oil or gas or whatever, which inturn results in a tax loss. So you have to lookfor the real net difference. And the interestingthing is: that difference is positive! That is dueto the fact that retrofit work is done with em-ployees here in Ireland, or in Germany, whilethe other thing [oil or gas production] is donefar away. That’s what makes the difference.

L:You made some comments recently about

the importance of retrofitting to a very high

standard rather than, say, a medium stan-

dard�do you think that’s a mistake that we’re

in danger of making In Europe right now?

W: Yes that’s a big problem. This mistake isbeing made all the time, everywhere. We haveto keep in mind that we are not retrofitting abuilding every two or five years, because peopleare reluctant to carry out major renovations. It’s clearwhy — retrofitting not only costs money, it also

creates dirt, and it’s noisy�so you try to avoid it.

So the fact is you do it and you won’t do it againfor 40, 50 or even 60 years. That’s a long time�On the other hand, from an environmental point ofview, it’s good to do it only every 50 or 60 years,long lifetimes reduce the environmental impacts.

But that way if you replace a window now,you’ve replaced it for the next 50 years. Soit’s really important what you choose now. If anew window costs €400 for example, and it’sjust €15 more for triple glazing, you would bestupid not to go with triple glazing. This iswhat I think we should really communicate. Ifyou do something with your building, pleasethink about the choices you make as they willaffect your building for the next 50 years.Don’t choose double glazing, but triple glazing.Don’t add 10cm of insulation but 20cm or 24cm.

L: One thing that we’ve noticed, and you’ve

probably seen this yourself, from architects who

maybe focus more on ecology than energy

efficiency, they tend to have a kind of scepticism

of airtightness and mechanical ventilation�

W: We had the same discussion in Germanyand Austria 15 years ago. But that changed

very rapidly. You have to really show what theproblem is if you don’t have an airtight con-struction. If your window isn’t airtight, you getair exfiltration through parts of your window, youget condensation inside your window, andyou get mould growing inside your window�It took only five or six years in Germany andAustria to convince almost everybody that it’sa good idea to build airtight.

Now the discussion on mechanical ventilationstill hasn’t come to an end in Germany. Thereare two points to it. One is that some peopledon’t like to have air coming in through a duct.I think by now it has been quite well demon-strated that it works really well. The otherthing is cost. And we have to be honest, at themoment, the cost of mechanical ventilationwith heat recovery is still relatively high, andit’s not so easy to show that it’s cost-effective.Today, insulation is cost-effective, triple-glazedwindows are cost-effective, but mechanical ven-tilation with heat recovery isn’t quite there yet.

I think what we need now is the same thing thathappened with [triple-glazed] windows. Whenwe started using these windows, the extra costwas not €15, it was €150 per square metre,which was far too high. But we knew that wewould be able to reduce it. It’s the same here.

Look at a laundry machine. Cost? €600. Andcompare that with a ventilation system. Cost?€2,000 [for the MVHR unit alone]. Now, whichof these devices is more complicated?

L: The laundry machine?

W: Definitely the laundry machine. So you seewe can reduce these costs, and that is whatwe have to concentrate on now. This might be

another area where we could work togetherwith your journal, launching a competition forreally cost-effective ventilation systems. Andit’s not only a question of the system, it’s alsoa question of how many ducts you are goingto install. Looking at what has been built, evenin Germany — complicated systems with muchtoo much ductwork. It’s not necessary at all.

I think for a dwelling, the costs for mechanicalventilation should be in the range of €3,000[for the whole system including MVHR unit,ductwork and installation]. That’s reasonableand we can get there. And once we do getthere, there will be no more discussions, be-cause it’s so much better. You can see that atthe International Passive House Days, youcan ask the homeowners.

That’s one of the reasons why the InternationalPassive House Days are so important� Peoplewho live in passive house dwellings sharingtheir experiences is much more convincing thananything that comes from an expert. Peopledon’t trust experts any longer, and that’s good!

L: What do you think are the biggest mis-

conceptions about passive house?

W: Well, there is one thing at the moment�those who don’t like passive houses, they sayit’s too expensive, something you need a lotof extra money to realise. That’s what they’retrying to communicate at the moment �Someparts of the building industry wants to coun-teract the European legislation�they talk about15% or 20% extra costs, and that’s not true!

L: We see projects where someone has

built a passive house and then put in a big

and complicated heating system. And if they

can afford to do that themselves it’s fine,

but that will be expensive, and I guess maybe

that can create the impression that passive

house is expensive.

W: That’s another reason why it’s so importantto document good examples. Of course thereis scepticism, and as a scientist I think it’s goodto have a sceptical approach, because thereare a lot of people around who promise a lot of thingsthat don’t work. And to counteract the skepticismagainst passive house, you need to show goodexamples. So we need buildings which reallyshow that it works with a simple heating system,and that it’s also very comfortable.

L: What do you think the next big goals are

for passive house, both in terms of cam-

paigning and lobbying, and then in terms of

the technical side of things — what are the

Passive House Institute’s next big ambitions?

W: Wow! There are lots of them. The most im-portant thing generally is refurbishment, thereare lots of things to be solved there. You knowTomás O’Leary is working with us on the Eu-roPHit project [an EU backed project dedi-cated to step-by-step retrofitting]. I think this isthe most important issue right now.

And on the other side we are looking at dif-ferent climates, how to build passive housesin a tropical or subtropical climate. We are ina very early phase of collaboration with theChinese. China might go passive house soon.That would mean an important contribution tothe reduction of CO2 worldwide, because Chinais the world’s biggest growing constructionmarket.

“If a new window costs €400, and it’s just€15 more for triple glazing, you wouldbe stupid not to go with triple glazing”

Can Ireland retrofit its building stockby 2050 & cut energy use by 80%?

Under the Energy Efficiency Directive, EU countries must submit a plan to renovate their entire buildingand cut its energy use by 80%. But achieving these goals will require a revolution in our thinking, saysPat Barry of the Irish Green Building Council

The Energy Efficiency Directive wasagreed last year by European memberstates, setting binding targets particularlyfor public sector buildings to beachieved by 2020. However realizingthat such short term targets can getin the way of long term goals, articlefour of the directive also required eachmember state to submit a long termroadmap for renovating the entirebuilding stock by 2050. This shouldachieve an 80% reduction in energyfrom the built environment. The firstdraft roadmap needs to be submittedby the end of April 2014.

Renovation of this scale, even if it iscarried out over 35 years, requires areal strategic shift in our thinking. Ifyou are looking for an 80-90% cut inenergy use from the building sector, youhave to use a back-casting approach,to be sure that work you do todaywill help, and not hinder your journeyto the final goal.

What is required is a genuinely ambitiousstrategy that has the buy-in of all theplayers, incorporating long termthinking, that goes well beyond a singlepolitical lifetime. It needs clear inter-mediate targets, with monitoring andevaluation processes. The roadmapneeds to address the whole buildingstock, not just residential. It shouldalso integrate other society goals such

as creation of employment and im-provement of health and environment.Most importantly, it needs creative,flexible thinking.

Not only the construction sector, butbroader society need to take ownershipof this plan, which will shape our col-lective low carbon future. The key tosuccess is collaborative policy-mak-ing by all organizations, professional,social and industrial.

Yes some of the challenges are tech-nical. For example in the domesticsector, few householders are likely toborrow the money to do a completedeep retrofit in one go – the so calledbig bang approach. It is more probablethat people will work on their housebit by bit over a number of years, orpossibly decades. So how do wemake sure that each piece of thatwork, links up together to achievethe final goal: an 80-90% cut in energy?

The key barriers are not just technical,but social and political. This is clearfrom some of the study documentsprepared for the government’s BetterEnergy Financing scheme. Sometimesit’s just that people are ....difficult!

For example, if we all agree that theonly sensible way of doing retrofit isblock by block rather than house byhouse, then how do we stop individualsopting out, even if all their neighboursagree to it? How do you deal withthe split incentive between landlordand tenant? How do you deal withthe issue of energy prices in an un-equal society, being too high forthose in fuel poverty, but too low tomotivate action by others? How doyou stop politicians running forcover, when faced with the 'I amholding the baby' fuel poverty argu-ment being made against energyand carbon levies? How do youagree what are fair incentives in thetaxation system? And that's just theprivate residential sector!

With our national politicians lockedinto five-year election cycles, weneed to develop an agreed roadmapthat gives certainty. Much of thefunding – particularly for the non-do-mestic sector – will come from in-vestment funds, who need steadyavailability of investment grade retro-

fit opportunities, and a stable policyenvironment. Innovation also needscertainty.

Look across the water, as prime ministerCameron undoes years of good pol-icy development under pressurefrom the Daily Mail and Ed Milibandto reduce energy prices. Politiciansneed cover, and policies and strate-gies need to be agreed between thesocial partners to give them thatcover, when the going gets tough. Allthe social partners and all politicalparties need to agree some commonprinciples and then work out howthese are best achieved.

Other European countries have alreadystarted the process. President Sarkozyinstituted the Plan Batiment Grenelle,an ambitious round table involvingover one thousand professionals andstakeholders, to help deliver thetransformation of the French buildingstock. Denmark also engaged in an18 month collaborative policy makingprocess with 200 industry and societystakeholders whittling down the creativeinput to deliver a set of 75 policy rec-ommendations. The key lessonsfrom the Danish process was to includethe 'unusual suspects' to achievegenuinely creative policy.

This is not going to be easy. Therehas been talk before in these pagesof a drive for renovation in order tofree Ireland from fuel imports. Weare now faced with the 'businessend' of how we actually do it! I urgeeveryone to input into the processover the next few months, to helpcreate a roadmap that engages andexcites not only those in the industrybut the general public. Consultationon the national implementation ofthe Energy Efficiency Directive closedon 13 November. The scoping ofhow article four in particular can bedelivered will be released for consultationover the Christmas period.

Confused about EU law and what iscoming down the tracks? IGBC hasdeveloped in conjunction with the WorldGreen Building Council an accredited,free CPD course. “EU policy andLaw for Green Building” which will bedelivered by Philip Lee of Philip LeeSolicitors on 4 December 2013. Seewww.igbc.ie

“The only sensibleway of doing retrofitis block by blockrather than house byhouse. How do westop individuals optingout, even if all theirneighbours agree to it?”

Community Centre,

St. Gerold

The community of Saint Gerold occupies a steepsouthern slope in the Austrian Alps, commandingsweeping views across the valley below and themountains beyond.

The municipality's new passive house communitycentre, finished in 2009, is home to a preschool,playgroup, shop, function room and local authorityoffices.

The form of the building references the neigh-bouring schoolhouse, which is a protectedstructure, and the local church too. Sited atthe entrance to the village, the new building actsas a gateway to this remote community. It's alsothe first four-storey timber building in Vorarlberg,Austria's westernmost state.

The centre was constructed from prefabricatedtimber walls panels, most of it sourced from StGerold's own forests. All sawmill and joinery workwas carried out in the neighbouring village.

The building isn't just about energy though, but

ecology too: the timber framing is insulated withsheep's wool and wood fibre, materials like PVCand paints with heavy metals were designed out,and even the elevator was constructed with wood.

The building's space heating demand is 14kWh/m2/yr, and any warmth needed is providedby a geothermal heat pump, which also pro-vides cooling in summer. Waste heat dumpedby the shop's cold store is also captured forspace heating.

And with 2,000 metre mountains rising above thevalley, the views aren't bad either. �

This issue’s selection includes an Estonian space-saving modular build that would see its space heatingdemand fall by eight if built in Dublin’s climate; a family home on a tight site that became Seattle’s firstpassive house; an ultra low energy Italian timber box that acts as a confident, sustainable response to anatural disaster; and a passive community centre in the Austrian Alps that makes stunning use of timber.

INTERNATIONALSELECTION

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Park Passive,

Seattle

Situated in Seattle's Madison Park neighbour-hood, Park Passive is the city's first certifiedpassive house. Designed by NK Architects andconstructed by Cascade Built earlier this year, thefour-bedroom home uses 75-80% less energythan a house built to the state's building code.

"Passive house’s focus on performance, humancomfort and simplicity aligns well with our ap-proach to design," says Boyd Pickrell of NKArchitects. "It supports our mission to createdense urban housing that is responsive topeople’s needs and supportive of highly sus-tainable lifestyles."

The tiny site was tricky for the designers of thehouse, which has meaty 450mm double-studwalls and 600mm of insulation in the roof. Air-tightness is provide by the internal OSB board,sealed up with Siga tapes. Triple-glazed Intuswindows were imported from Lithuania.

The home’s vaulted ceilings connect the mainliving area to an upstairs play area, while the day-lit open staircase showcases wall panellingfrom a tree salvaged from the site. Salvagedwood was also used for the stairs and a bath-room counter. The rooftop deck offers views ofLake Washington and the Cascade mountainrange.

“Inefficient buildings are the number one con-sumer of energy in the world, and the largestcontributor to climate change,” says CascadeBuilt founder Sloan Ritchie. “Passive housedesign standards offer a way forward towardsnet-zero building with strategies that are rela-tively easy to implement – better windowsand doors, more insulation, improved air seal-ing. Unlike asking people to stop driving theircars, passive house reduces our carbon footprintwhile increasing comfort and quality of life.” �

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Smart Design House,

Estonia

Passion Smart Design House is a prefabri-cated modular design by the Passion Groupand Estonian firm Architect 11 — and this re-cently completed 40 square metre version isthe first prototype built.

Designed to be erected in just a day or two —with most work done off-site — this unit is in-tended as an addition to an existing house, oras a guesthouse or holiday cottage.

The structure is delivered fully furnished, withfurniture and appliances "attached" inside.The architects say that by constructing thehouse in-factory and minimising time on site,they reduce their impact on the local environment.

The dwelling is constructed from a glulamframe that's insulated with mineral wool, andsolar thermal heating features too. The housewas designed with PHPP, though the archi-tects say that some assumptions made by thesoftware — that the house will be occupiedyear round, for example — do not apply to thisprototype unit.

This building's space heating demand is 54kWh/m2/yr — well outside the passive housestandard of 15 kWh/m2/yr. But architect EeroEndjärv switched the climate setting for thehouse to Dublin, and the space heating de-mand dropped to just 7kWh/m2/yr — mean-ing that if this was built in the Irish capital, itwould be a passive house. �

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Energy Box,

L'Aquila

The larch-clad Energy Box in L'Aquila, Italyhas replaced a home destroyed during the2009 earthquake that devastated the region.Architect Pierluigi Bonomo wanted EnergyBox to mediate between the past and future,so this new low energy dwelling rests insideremnants of the original house's stone wall:the old stone walls reflect the past, while thenew energy efficient, lightweight, earthquake-proof timber structure points to the future.

Completed this year, the house was constructedfrom cross-laminated timber, and the walls areinsulated with glasswool insulation internallyand woodfibre externally. On the south facade,wide gaps between the larch planks allow fornatural lighting and solar gain, while slidingtimber screens provide summer ventilation.

Energy Box was constructed to the Italian ClimateHouse Gold standard, which requires ther-mal-bridge free construction, a space heatingdemand of 10kWh/m2/yr, and airtightness ofless than 0.5 air changes per hour – levels which,without interrogating the inner workings of thestandard, all seem tighter than the passivehouse requirements. (As an aside, there’s anargument about whether tighter standards thanpassive house are necessary, given the di-minishing returns involved).

The house's tiny heating demand (7kWh/m2/yr)is provided by heat recovery ventilation and afew small electric radiators. Energy Box alsomakes rich use of materials salvaged from thedemolition of the old house, such as stone,steel and wood.

The house features a solar photovoltaic facadetoo, and another PV panel on the roof. This meansthe house classifies as "nearly zero energy,"according to Bonomo.

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The window company who came to fit out architectHelena Fitzgerald’s passive house in Carlow hadallowed five days for the job. Such was the pre-cision with which the frame had been plannedhowever that they only needed a day and a half.

Donal Mullins of Shoalwater Timberframe saysthat the levels of accuracy in the frame wereunbelievable. “Helena had worked everythingout to the millimetre,” he says. “All that accuracyin design spills through for everyone so that thebuild goes really smoothly. Everything wasdone on paper beforehand and that’s the wayit should be done. There were no meetings onsite with the usual head scratching; ‘how are

we going to get around this one? Whose faultis this?’ She was a pleasure to work with.”

Helena cut her teeth working with BuildingDesign Partnership (BDP) in Scotland, beforereturning home to Carlow in 2005. Four yearslater, she set out to build a passive house forherself and her young family.

“My husband and I understood that this wasthe biggest project we were ever going to getinvolved in and that it had to reflect our val-ues,” says Helena. “My husband was reallysupportive about trying to develop our ownproject as a passive house.”

Built on her family’s farmland, the site on whichHelena planned her house provided spectacularviews of Mount Leinster and the Blackstairsmountains, and featured a mature oak tree.The problem however was that these werefound to the east and west of the site respec-tively. Passive design seeks to make the mostof solar gains by maximising glazing on thesouthern elevation.

Making the most of the site’s natural featureswhile maintaining the passive approach was achallenge which Helena relished. “Many of thepassive houses I had seen appeared quitescientific in their approach,” she says. “They

Passive architect

weren’t very expressive forms, their architec-tural quality wouldn’t appear to have been apriority. If passive house is to be applied moregenerally, you need to be able to use it on allsites, not just the ones which have the southfacing aspect to the rear. I was really inter-ested to see how flexible it could be.”

Acutely aware of the ‘privilege’ of building ona green field site, she wasn’t solely concernedwith the energy profile of the house. In addi-tion to the mountain view and the mature oak,the site also featured an old granite dry stonewall and a slight dip in the ground to the southeast corner. Helena was keen that the design

should respond to these features. “The otherpreoccupation was land use. We live in thecountryside and we have a relatively large site;it’s in excess of half an acre and we didn’t wantto be mowing the lawn all the time. We wanted tothink about how we were going to be usingthis piece of land.”

In coming up with a design, Helena dividedinto four distinct areas: a public/arrival area tothe north east and a functional/working gar-den for wood storage and clothes drying tothe south west, with a raised bed percolationarea providing shelter for the kitchen garden.The kitchen/dining area opens onto a leisure

garden to the south east, which includes theonly area of conventional lawn. In the finalquarter to the north east, she had planned awilderness garden, though this is now underreview because the soil type doesn’t appearappropriate.

To make the most of the key features to theeast and west, the living areas were given aneast/west orientation with informal kitchen,dining and family room to the south. Serviceswent into the northwest corner, with utility andentrance, neatly facilitating a division betweenthe public arrival space from the more inti-mate kitchen garden. “We decided not to �

new build

walks the walk withCarlow home

None of the editorial team behind Passive House Plus has the good fortune to live in a passive house –at least not yet – meaning our promotion of passive house comes with more than a hint of “Do as I say,not as I do”. That’s emphatically not the case with certified passive house designer Helena Fitzgerald,who chose to practice what she preaches with her own home, to stunning effect.

Words: John Hearne

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have a garage because people don’t usegarages, they just need a space to store bikesand stuff,” says Helena. “This meant that weended up with an L shaped plan...Having thisL shape meant we could have the longer ele-vation to the south, which was critical in terms ofgetting enough southern light into the building.”

The deployment of glazing has of course asignificant impact on the performance of thehouse. Helena here was guided by how eachroom was used. In the kitchen/dining area,which opens onto the recreational garden andfaces south, the windows go right down tofloor level. In the more formal areas east andwest, smaller ‘picture’ windows capture spe-cific views. “If we put smaller windows in eastand west, we would have had a better ther-mal performance for sure, but the amenityvalue of the views would not have been thesame. There was a trade-off there.”

Here again is a reaction against the notionthat passive must be hamstrung by the sci-ence. Strict interpretation of the guidelineswould leave northern elevations almost blank,with extensive glazing to the south. A moreliberal interpretation allowed Helena a moreexpressive building, though this meant thatshe had to find ways of compensating for anyresulting heat losses in other ways. She pointsout too that that you can increase glazingwhile minimising heat loss. It’s the frame that

tends to let the window’s energy performancedown. “If you have lots of divisions, your win-dow is going to perform less well than if youhave larger panes of glass. That’s taken tothe ultimate in the master bedroom window,which is just a huge fixed pane of glass withno openings.”

While the budget did not stretch to passivecertified windows – the options Helena lookedat commanded a considerable premium overnon-certified ones available at the time – shesays the Kneer-Sued-fenster triple-glazedunits still achieve close to passive standards.

When it came to choosing materials and abuilding method, Helena was keen to main-tain the sustainable philosophy she broughtto the rest of the project. She learned aboutSiberian larch cladding from BDP colleagueswho had used this material on the Isle ofSkye, off the northwest coast of Scotland. Thetimber is untreated, and has a rough, organicappearance. Not only does it respond well tothe existing tree on the site, it also weathersto a pinky grey colour, very similar to the ex-isting granite wall. “In five years time, I thinkthis building will be almost invisible from theroad,” says Helena. “It will disappear.”

The combination of Supergrund foundationand cellulose-filled timber frame constructiondelivers an envelope befitting of a passive

house. Thermal bridge free construction – anessential part of passive house design – wasachieved through the use of a continuous in-sulation layer which wraps the entire building.Helena trained in thermal modelling and pro-duced all the construction details herself.Shortly after she had completed the workhowever, the NSAI introduced a registrationscheme for thermal modelling. Helena foundregistration an expensive process, and de-cided that commissioning new thermal bridgedetails from a registered modeller was bothunnecessary and beyond the reach of thebudget. The result is that for Deap purposes,Helena has had to use a set of default detailswhich drastically misrepresent how thermal bridgesare circumvented in the house, leaving herwith a poorer BER certificate.

Airtightness was achieved primarily throughthe use of OSB board, taped using Intelloproducts. Donal Mullins of Shoalwater, whotook responsibility for this element of the build,says that he was initially nervous about usingOSB as an airtight layer.

“This was a challenge because OSB isn’t acertified board for airtightness,” he says, “butI knew that detailing the project properly anddealing with all the crucial areas would limitthat risk. We had to think outside the box withthe airtightness, but it did pay dividends in theend with the final reading we got.”

Gavin O’Sé, who conducted the airtightnesstests and carried out the BER assessment, reportsa final test air change rate of 0.38, an excellentresult, well inside the passive house thresholdof 0.6 ACH.

Solar thermal panels provide the bulk of do-mestic hot water needs. Helena consideredtwo options for space heating and domestichot water backup. “We couldn’t imagine a liv-ing area without a flame so a room-sealedstove was included in both options. The firstwas an air to water heat pump with a roomheating stove, the second was a stove withback boiler.” Because of budget restrictionsand the fact that the heat demand was so low,Helena didn’t want to duplicate the systems,so she opted for the latter. This option, whileit did suit the family’s lifestyle, did howeverhave an impact on the final BER, owing to thelack of heating regions or thermostatic con-trol. “Stoves are inherently manually oper-ated,” she says. “We were penalised for thisin the BER process due to the lack of ther-mostatic control.”

As for fuel usage, Helena has an abundantbiomass supply that comes from maintaininghedgerows on the family farm – a supply thatfar ourstrips demand. “We stopped lightingthe stove in April,” she says. “We’ve lit it twiceso far this winter, but mostly because we hadpeople staying who wanted to see it in action.” �

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Electricity costs are working out at approximately€95 per month – the only actual energy costat the moment.

Helena also decided not to go for passivehouse certification – which would have addeda cost of circa €1500 – due again to budgetconsiderations. “I have another project pendingcertification, so I didn’t really need to do it formy work. I would have liked to do it on thisproject but we needed to put a kitchen in.”

The family moved in March 2012, during thecold snap, when temperatures outside rarelygot above freezing during the day. “It was verycomfortable,” says Helena. “If there’s any sunat all when it’s cold, you’re toasty.

“You could be very critical of the house, youcould say that it is not the most economic wayof achieving passive house but it is a veryparticular site and I had to respond to that. IfI had just put a rectangular block here, itwould have been a missed opportunity. Iwanted to ask, can you achieve this energyperformance with a more expressive and ar-chitectural form? If passive buildings don’t re-spond well to their setting, will people wantthem? Or is it going to be something that’sjust peripheral fascination of a few, motivatedindividuals?”

SELECTED PROJECT DETAILS Architects: Helena Fitzgerald ArchitectsExecutive architect: Kelliher Miller ArchitectsStructural engineer: ONCE Civil & Structural Ltd

BER assessor and airtightness tester:GreenbuildMechanical contractor: Michael WallElectrical contractor: Doyle Bros ElectricalTimber frame: Shoalwater TimberframeCellulose insulation: Isocell LtdMineral wool insulation: Isover IrelandWood fibre insulation & airtightness systems:Ecological Building Systems LimitedOSB: SmartplyPIR insulation: XtrathermFloor insulation: Kingspan AerobordAdditional airtightness tapes: Tremco Illbruck LtdWindows and doors: Kneer-SüdfensterSteel frame for brise soleil:Murtech Engineering LtdScreeds: Dan Morrissey IRL LrdGGBS for screeds: EcocemStove: OlsbergSolar thermal: Kingspan Solar via PolythermUnderfloor heating: PolythermHeat recovery ventilation:Pure Renewable Energy LtdLighting: Mid West Lighting/Habitat/Mawa DesignWater conserving fittings: HansgroheSanitaryware: Duravit/BetteFit-out joinery: James Hanrahan CarpentryEngineered oak flooring:Wogan Distributors via Heiton BuckleyCoir mat entrance carpet: FootfallRoofing membrane: Laydex Ltd.

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new build

PROJECT OVERVIEW:

Building type: 233 square metre detachedtwo-storey timber frame house with a 14 sqm shed

Location: Borris, Co Carlow, Ireland

Completion date: March 2013

Budget: not disclosed

Passive house certification: not certified

Space heating demand (PHPP): 14.9 kWh/m2/yr

Heat load (PHPP): 11 W/m2

Primary energy demand (PHPP): 92kWh/m2/yr

Airtightness:0.3875 ACH / 0.418 m3/hr/m2. (An50result of 0.6 would have made the building fail toreach the passive house standard as the spaceheat demand would have risen to 15.8 kWh/m2yr)

BER: B1 (78.47 kWh/m2/yr)

Thermal bridging: The structure was designedto be thermal bridge free, as required for a pas-sive house, with a continuous layer of insu-lation around the perimeter of the buildingenvelope. Specifically, an insulated raft foundationwas used, 50mm wood fibre board was fixedto the external face of timber frame walls andPIR insulation used on top of the roof deck.Care was taken to ensure continuity of theselayers at the substructure/superstructurejunction and where the wall meets the roof.At window openings, timber framed windowswere used; externally, wood fibre board insulationoverlapped the windows by a minimum of 50mmand internally the reveals were insulated. In DeapThe Y factor value used for thermal bridging wasset to a default level as full calculations weredeemed too costly.

Ground floor: Supergrund insulated raft foundationsystem with 300mm EPS. U-value 0.113

Walls: Factory-built timber frame with 25mmuntreated Douglas Fir cladding externally inboard on board format, followed inside bytreated softwood battens and counter-battens,Pro Clima Soltex WA breather membrane,50mm Gutex Ultratherm woodfibre board,222 x 44mm Isocell cellulose-filled timber stud,18mm taped and sealed OSB3, 50mm servicecavity insulated with Isover Metac insulation, and12.5mm Fermacell board internally. U-value: 0.129

Roof: 60mm pebbles on Alkorplan membranebuild-up on 100mm Xtratherm FR MG insulation onAlkorplus vapour control layer on 18mm OSB3structural deck (part of timberframe) on 225 x 44mmrafters filled with 220mm Metac insulation, Pro ClimaIntello vapour control layer, 35 mm uninsulatedservice cavity, 12.5mm plasterboard ceiling.U-value: 0.104

Windows: Kneer-Süd-fenster HF90 1000triple-glazed spruce windows, with argon filling.Overall U-value: 0.83

Heating system: 80.5% efficient OlsbergTolima Aqua Compact stove with back boiler,plus 40 Kingspan Thermomax Varisol DF100tubes, supplying 200L DHW cylinder, and400L buffer tank supplying underfloor heatingand towel radiators in upstairs bathrooms.

Ventilation: Paul Novus 300 heat recoveryventilation system — Passive House Institutecertified to have heat recovery rate of 93%and electric efficiency 0.24 Wh/m3.

Green materials: Fermacell, cellulose in-sulation, untreated douglas fir cladding.

(clockwise from top left) It’s a tight squeeze up a narrow road as the factory-built timber frame is deliveredto site; a combination of OSB, tapes and membranes form the airtightness strategy; the cellulose insulationbeing installed to provide a continuous, cold bridge-free layer of insulation

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Passive house is all about usingtiny amounts of energy to delivermaximum comfort for those livingand working in buildings that meetthe standard. So why did WainMorehead Architects turn to theirpassive house knowhow whendesigning a whiskey distillery thatwon’t have any occupants?

Words: Lenny Antonelli

At its heart, the passive house concept is aboutcomfort. Sure it’s about saving energy and cuttingCO2 emissions, but you’ll find a committed fewachieving those goals by turning the heat offand sticking on a heavy jumper. The differencewith passive house is that it achieves these goalswhile providing a warm, healthy indoor envi-ronment.

So what’s the point of using passive houseprinciples when designing a building that won’thave any occupants?

The new Irish Distillers Garden Still Housebuilding at the company’s Midleton distillerynever aimed to reach what some consider anonerous low energy standard. But its design-ers Wain Morehead Architects found that ap-plying ‘fabric first’ passive house principlesserved the unique demands of distillery design.Irish Distillers — a subsidiary of French multi-national Pernod Ricard — produces Jame-son, Paddy, Powers and other Irish whiskeys.

“We were able to use all the tools and techniqueswe used from doing passive house buildings andapply it to this building,” says architect JohnMorehead.

First, airtightness means the facility can containany alcohol fumes and expel them through adesigned ventilation system and diffuse them— rather than have them exit at random throughgaps in the building envelope. This is importantfor protecting the building structure, as alcoholvapours encourage the growth of certain mouldsand can pose a major fire risk.

Distillation operates in high temperatures andstill buildings can become very humid at times,so preventing condensation — either on theinternal surfaces or interstitially — was also key.Eliminating cold spots through good insulation,airtightness and a design free of thermal bridginghelped achieve this.

“If you didn’t have good levels of insulation andvapour control you could end up with conden-sation in the envelope,” John says. “We didn’twant to be constructing a building that wasgoing to fail in 40 years — that would havebeen a huge reason for getting those levelsfor insulation. We also wished to maintain ad-equate temperatures during shutdown to reduceprocess and sprinkler pipework insulation re-quirements.”

The metal-stud opaque walls are insulated toa U-value of 0.16 with Rockwool Flexi. They’reclad externally with Tegral Natura Pro rain screenon a breather membrane and Durapanel weatherlayer, and internally taped and sealed withTegral Hydropanel.

Irish whiskey distillery

puts fabric first

The roof is insulated to a U-value of 0.15 with140mm of Kingspan Thermaroof PIR insula-tion and 60mm Rockwool in the troughs, andalso includes a Soprema vapour control layer.The ground floor slab is insulated with 150mm ofKingspan Styrozone XPS insulation.

The airtightness target on the project was oneair changes per hour, though no blower door testwas done.

“There’s no reason why we shouldn’t have wellexceeded it, because the construction is actuallyquite simple with not too many connections,”John says.

Besides protecting the structure, there’s an-other reason the design team wanted to pre-vent condensation — to protect the building’sgood looks. The glazed facade that shows offthe huge pot stills forms an architectural cen-trepiece at the distillery, and would be fairlyineffective if it fogged up.

Counter-intuitively for passive house designers,this glazed wall faces north. Distillation producessuch big internal heat gains that orientating thebuilding south to capture solar energy wasn’tnecessary and the radiant asymmetry createdby the cold surface could incite air movement.

Designed by Billings Design Associates andsupplied by Alucraft , the double-glazed curtainwall has a U-value of 1.6Wm2K. One of the hugeglazed sections in the gables can be openedto facilitate plant access.

The transparency and clarity of the glazing waskey. This facade includes frameless verticaljoints, glass-to-glass corners and uses a whiteglass that’s low in iron.

The double-glazed roof lights are removabletoo — the pot stills were actually loweredthrough them during construction.

The south-facade features a Tegral SolarWallair heating system. This consists of a dark sheet

of perforated, heat-absorbing sheet metal. Asair passes through the perforations it is warmed upby the wall. Once warm air reaches the cavitybehind, it rises to the top of the building. If heatingis ever needed — such as for frost protectionwhen the facility is shut down over Christmas— this warm air can be distributed using electricfans. If it isn’t needed it’s simply vented out of thebuilding. The SolarWall system can produce75,000kWh of heat annually, while the thermalmass of the 800 square metres of exposed concreteinside helps to regulate internal temperatures.

Perhaps the crowning achievement of thebuilding is that its huge ventilation demand ismet passively. By ensuring the temperatureinside is always kept at least 5C higher thanoutside, a passive stack is created: warm air risesup through vents in the roof, creating a chim-ney effect that pulls fresh outdoor air throughvents in the floor. According to John More-head, the ability to maintain a 5C temperaturedifference ensures the system will manage toexchange 5.61 cubic metres of air every second.

For building services engineer Mark Ryan ofthe PM Group (who were also contractors onthe project), the very fact that the design teamconsidered natural ventilation makes this projectunique. “Most industrial plants I’m involved inwouldn’t even ask the question, they’d just putthe fan in,” he says.

The project is partly inspired by old distilleriesthat pioneered the use of passive stack ven-tilation. Mark says the most common problemwith passive stack is that it can work too well,creating huge draughts. Here, closing some ofthe dampers in winter — when the tempera-

ture difference between inside and outside isgreatest and the stack effect strongest — willhelp control this.

“If you have poor building envelope performanceit will impact on the stack effect significantly,”John Morehead adds.

Besides the building itself, Irish Distillers hasdrastically improved the efficiency of its owndistillation with the latest technologies.

Its updated distillation process is able to extract99% pure alcohol from raw material as op-posed to 92% before. Maize cooking is alsomuch more efficient now, and the new potstills recycle heat over and over to maximiseefficiency. In fact, the operational energy �

“If you didn’t have good levels ofinsulation and vapour control youcould end up with condensationin the envelope”

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requirement at the facility is 1.5kwH per litreof alcohol, compared to from 2.56 previously.

“Sustainability was a pre-requisite from theoutset, from the design stage. Every elementof design was examined from a sustainabilityperspective,” says Tommy Keane, head ofdistilling operations at Irish Distillers. Becausenew equipment is expect to last 30 years, Keanesaid it was imperative to install the latest, mostenergy efficient plant.

“I had looked at some passive buildings, andI know that John [Morehead] is pretty passionateabout it. We had a few chats just to air a fewideas, and eventually we sort of ran with it,”Tommy says.

“We’ve effectively reduced the energy consumptionby about 50% compared to the original plant.”

This doesn’t just apply to the new buildingthough — the company has installed the mostmodern equipment throughout the distillery.

Besides the impressive energy achievements,Irish Distillers now has a striking contemporarystructure to show off modern distillation and sitalongside the 18th century buildings on site.

Within 11 months of work starting on site, the firstalcohol had been produced. Three pot stills arenow in operation at the building, and threemore are currently being manufactured to sitalongside them.

“We wanted a signature building to show off whatare effectively the largest pot stills operatingin the world,” Tommy says.

Architect’s statement — John Morehead,

Wain Morehead Architects

The Garden Stillhouse building is located withinthe Midleton distillery complex. It is an Atexrated building and is within a Seveso site. Therestrictions on the use of components andmaterials is therefore heavily monitored to onerous

health and safety standards. As alcohol fumesare heavier than air, their effective displacementhad to be addressed at an early design stage.

FM Global, the insurers, had an active role inauthorising the use of approved constructionmethods at the early design stage and issuingproject specific guidelines and performancetargets. Time was of the essence as this build-ing played a key role in the major expansionand energy reduction programme embarkedupon at the home of Jameson.

Apart from having process requirements thenew still house has to be a signature buildingand to compliment the 18th century buildingsalready found in the distillery grounds. Thestills are the focal point of the process formand had to be clearly visible from outside. Thenorth facing, raked glass wall is constructedso as to minimise reflection and increase visibilityof the stills within. The cool surface of the glasscauses rapid cooling and inversion of the warmedair as it comes in contact. The U-value of thislow iron white glass double-glazed system curtainwall system is 1.6.

The built result is considered to be somewherebetween a process building and a cathedral.

The building footprint is 960 sq m. The lower groundfloor houses a significant amount of plant whichis hardly evident when viewed externally. Theupper floor of the building houses the largecopper pot stills, based on a pattern for theoriginal Jameson stills which incidentally, arethe largest stills in Europe.

This 10m high hall has a central concretewalkway with the stills located either side in aventilated floor zone. The grated flooring al-lows fresh air from the lower ground floor tocirculate through the building and vent throughslots in the apex of the skylights over. Theskylights themselves are 7.6m x 7.6m in areaand removable to facilitate replacement or re-newal of the individual pot stills. The form of

the roof-lights also provides a significant amountof solar gain to maintain temperatures duringthe shutdown period.

The stack effect moves 20,200m3/h of airwithout any additional mechanical support.The building is designed with future expansionin mind: there is a provision for three morestills which will increase capacity from 33 mil-lion litres of pure alcohol per year in 2011 to64 million litres following the works. Internallinings were kept flush to reduce dust accu-mulation and aid effective flow.

The building envelope is designed to a veryhigh level of thermal performance with U-valuesof 0.16 for the walls and 0.15 for the roof areas.The omission of thermal bridges and conden-sation risk was carried out using Therm andPsi-Therm tools. Resilience and longevity wereof paramount importance as maintenancescheduling is predetermined. The selection ofexternal rain-screen materials and claddingsystems reflected their aesthetic and resiliencein a distillery environment.

The addition of Solarwall cladding system tothe south of the building, provided additionalcapacity of 76,700 kWh/yr of preheated air.This wall has minor perforations which allowsunlight to warm the airspace behind thepanel. This warm air is collected in a plenumand is then ducted into the building to assist inthe heating of the space during times of build-ing shutdown. The thermal mass of the lowerfloor area is significant with 800m3 of concretewithin the thermal envelope as a heat sink, againfor shutdown. Having this latent heat availablepermits the installation of non-insulated sprinklersystems, reducing costs and aiding leak detectionand maintenance.

SELECTED PROJECT DETAILSClient: Irish Distillers / Pernod RichardArchitect: Wain Morehead ArchitectsContractor & project management: PM GroupCivil, structural, mechanical engineering:PM Group�

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(clockwise from top left) An early 3D image of the building; Rockwool insulation being applied to the walls; installation of the double-glazed curtain wall; thestructural elements to the primary steel are isolated from the interior environment by thermally broken Isokorb connectors; (p43) (top left) the walls are cladexternally with Tegral Natura Pro rainscreen, and the south facade also features a Tegral SolarWall heating sytem (top right); the SolarWall is perforated toallow air to pass through, and in doing so is heated by the wall’s warmth

Planning consultant: McCutcheon MulcahyFacade specialist: Billings Design AssociatesFire consultant: Cantwell, Keogh & AssociatesLandscape consultant: Forestbird Design

Ground works: PJ Hegarty Envelope contractor: AlucraftStructural steel: Cronin BuckleyRoofing contractor: MultiRoofing Systems

Glazing consultants: Nazeing GlassworksSprinkler system: WritechSolar wall & cladding: TegralSolar wall design: CA GroupIsokorb thermal breaks: Contech AccessoriesBasalt wall ties: LongsAluminium louvres & brise soleil: QEF LtdAluminium doors: AMSRoof membrane: Soprema IrelandInsulation: Kingspan/Rockwool






PROJECT OVERVIEW:

Building type: steel-frame distillery production building. 960 sq m footprint, 21.5m high (to apex ofroof-lights). The main access from the garden is via a bridge to an intermediate level. Access is restricted dueto the nature of the process. The retention of existing hedgerows and features has retained the gardensetting for this unique building.

Location: Midleton, Co Cork

Completion date: first base spirit produced in march 2013, practical completion achieved in August 2013

Cost: €3.6m (€3,750 per square metre)

Passive house certification: not sought

Airtightness: A full air leakage test has not been carried out but the building was designed to achieve 1ACH. The nature of the process and concerns regarding alcohol vapours and their volatile naturewas complimentary to ensuring that the overall envelope retained airtight and vapour control throughout.

BER: Not required

Thermal bridging: In order to limit thermal bridging a number of methods were adopted. 1. The wall construction generally is a ‘built up wall system which is fitted with an external boardingmaterial – (Duripanel) fitted to 95mm crossrails packed with Rockwool batts. Cross rails are fitted to175mm vertical rails packed with Rockwool batts. Internally a boarding material – (Hydropanel) isfitted to the vertical rails – joints are filled and sealed to be airtight. This boarding acts as the vapourcontrol and airtight layer. The boarding is faced internally with a self-finished lightweight trapezoidalliner sheet. Externally there are a number of differing finishes.2. There is an overhang roof element which is insulated to top, leading edge and underside. Thestructural elements to the primary steel are isolated from the interior environment by Isokorb units. 3. Cavity based masonry construction to the lower ground plinth makes use of high performance‘basalt’ wall ties to limit thermal bridging. 4. Underside of slabs insulated and the face of foundations are insulated to the underside of the builtup wall construction to maintain a complete thermal envelope.

Ground floor: Resin flooring, on 300mm concrete slab (power float finish), on DPM, on 150mm KingspanStyrozone N300R. U-value: 0.15 W/m2K

Walls: The wall systems are of built up metal stud/counter stud fully insulated systems with ce-mentituous boards of differing vapour permeability and densities to suit their location. They are generallylined with an internal profiled metal liner. An external rainscreen of fibre cement boards or profiledmetal sheeting completed the construction.

Rain-screen walls: 8mm Tegral Natura Pro rainscreen cladding (N251 Anthracite) on 40mm Tegralvertical rails, on Tyvek UV façade breather membrane, on 12mm Tegral Duripanel, on 90mm + 145mmsheeting rails full filled with Rockwool Flexi insulation, on12mm Tegral Hydropanel taped & sealedto form vapour check, on 33mm Tegral C33 liner sheets. U-value: 0.16

Roof: mechanically fixed Flagon SR membrane, on 140mm Kingspan Thermaroof TR26, on 1mm Sorpremavapour control Layer, on Rockwool (trapezoidal infill pieces to troughs – nominal 60mm), on profiledmetal deck – (Tegral Building Products) – thickness 1.0mm (profile 50mm deep), metal liner sheet(1mm) to perimeter. U-value: 0.15.

Glazing: double-glazed low-iron white glass curtain wall system. U-value: 1.6

Heating system: There is no traditional heating system provided in this facility. The building housespresently 3 of the 6 copper pot stills. These large stills, radiate significant heat during the processwhich is removed using the stack effect cooling.

Ventilation: passive stack ventilation system.

new build

ph+ 43

As passive house moves into themainstream, construction costs arebound to keep coming down, withincreasing competition among sup-pliers, and designers and contractorsbecoming familiar with the mostcost-effective routes to meeting thestandard. One recent self buildshows that low cost passive houseneedn’t be a distant aspiration –it’s achievable now.

Words: John Hearne

Meticulous attention to detail and a lengthyplanning phase has delivered a 2,375 squarefoot passive house in Co Down which cost£192,000 to build. PMC Architects has publisheddetailed costings for every element of the project,revealing just how affordable passive housecan be.

“It reassures people that it can be done at areasonable cost,” says Paul McAlister of thecompany. He points out that the passive housepremium is typically set between 10 and 15%over conventional build. (ed.- it’s questionablewhether passive house adds any additionalcost in the Republic of Ireland, due to changesto Part L introduced in December 2011.) McAlister’spassive house however cost just 8.35% more thana house built to Northern Ireland’s building regula-tions. His figures include just £3,000 of PC sumsand exclude professional and development fees.

He has compiled detailed tables which comparethe house with one built to Northern Ireland’sminimum standards, as calculated using theUK’s Standard Assessment Procedure (Sap)2009 software. McAlister logged each phaseof the build, from foundations and ground floorconstruction all the way through to the installationof domestic hot water and space heating systems.

By his calculations, the total cost of the con-ventional Sap 2009 house comes to £175,969.That’s just over £16,000 lower than the passivehouse cost.

In the coming year, he plans to run a detailedanalysis to identify the point at which the ad-ditional measures taken to deliver the passivespecification will have paid for themselvesthrough fuel savings. “It all depends on howoil and energy prices go, but those figures willgive it a different slant.”

Nor is this the cheapest house that McAlistercould have built. This, he says, was a high specbuild. “We know we could do it cheaper if wehad less sophistication. I believe we could doit for £75 a square foot if we used ordinaryconcrete tiles and so on. You used to hear someterrible stories about the cost of passive house,especially in the early days but I think that’snow in the past.”

McAlister became Northern Ireland’s first certifiedpassive house designer three years ago, butthis is his first certified passive house. “Therewere a number of people we did designs for,”says McAlister, “but the houses either didn’tget built or the client didn’t want to pay extrafor the certified products; the windows and whathave you. This was the first person who was

willing to go the whole way and get it certified.”

While the premium between conventional andpassive continues to fall, McAlister acknowledgesthat delivering certified passive in a one-offresidential setting still requires a highly motivatedclient. For the McGlinchey family who built thishouse, getting the energy profile of their houseright was as much about doing the right thingas building a comfortable, cost-effective home.

The rural, elevated site on which they planned tobuild their home gave McAlister a lot of free-dom when it came to orientation and layout.“We were very fortunate with the site itself inthat the main view was south west facing, soimmediately we were able to turn all the livingspaces towards the view, and open up the glazingtowards the view as well, which helped withachieving our energy rating.”

The brief specified a contemporary take on atraditional aesthetic. McAlister’s design takesthe traditional Irish long house with pitched roofand gives it a modern feel. It includes iroko tim-ber cladding, a porch feature at the entranceand double height space in the living room.

During the tendering process, the architectworked with one of the tendering structural in-sulated panel system (SIPs) companies to createworking drawings for the project. But whenthat company didn’t win the tender, a whole newset of drawings had to be drafted. The resultingdelay did however give the project team thetime to work though plans and iron out anypotential issues.

“We stopped and said ‘let’s get this right beforewe go on.’ We didn’t do it on a wing and a prayer.

Co Down passive housebuilt for under £200,000

We took the time to get the details redrawn,then we got them certified and did the thermalbridge analysis to make sure it all worked, sowe were quite rigorous in that sense.”

As with all projects of this nature, the centralchallenge for the architects lay in designingaway the cold bridges. Because PMC want tobuild in-house expertise in this area, they didall of the calculations themselves, then forwardedthe plans to the Passive House Academy inWicklow for verification.

The team also used the passive house soft-ware, PHPP as a design tool, working throughevery nuance of the plan to ensure that theyremained within passive house criteria.

McAlister explains that the structurally insulatedpanels (Sips) were selected as a buildingmethod because in the first place, the clientexpressed a preference for using timber in thebuild. “We liked the Sip panels because they’reinjected with insulation in the factory and forthat reason we did not have to rely on onsiteworkmanship to the same degree. The houseis a storey and a half with Sip panels on theroof as well, so we had a nice neat envelope.I liked it because I knew that it would perform.”

The passive tailored Sips – supplied by Warrenpoint-based manufacturer Sipfit – are the singlegreatest cost item in the spec, and the element

of the build which commanded the highestpremium over the equivalent conventional spec.According to McAlister’s tables, the passive SIPframe cost a total of £56,000. By comparison,the SAP 2009 construction, which is also a SIPframe – albeit with substantially less insulation– cost £44,800, a difference of £11,200.

Using Sips, in addition to providing factory fit-ted insulation, also facilitates eliminating coldbridges, because the system creates a con-tinuous thermal envelope through walls and roof.

Primary responsibility for airtightness lay withcontractor Kevin Mulligan of Baylands Con-struction. “There was a lot of work with the air-tightness,” he says. “A lot of attention to detailand trying to get my subcontractors used tohow you have to work around an airtightnessmembrane. Classic example: The plasterersnailed a three inch nail through the membrane tohang their radio. You’re just trying to teach olddogs you can’t do this, you have to try to getelectricians and plumbers up to speed; youjust can’t willy-nilly drill holes anywhere youwant, you have to plan where you’re going toput your cable and pipe routes.” �

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"There was a lot of work with theairtightness. Classic example: Theplasterers nailed a three inch nailthrough the membrane to hangtheir radio. You’re just trying toteach old dogs you can’t do this."

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Like Paul McAlister, this was Baylands’ firstpassive house, and inevitably, the project broughtthe team up a steep learning curve. Throughrepeated airtightness tests, Mulligan achievedsuccessively lower airtightness results untilhe finally broke through the magic 0.6 ACH.

McAlister also cites choosing a heating sys-tem as another challenging aspect of the job.

“It was designed to require 14 kWh/m2/yr. Thismeant it wasn’t a low enough heat load to becarried through the ventilation system so weneeded some sort of heat source. The calculationsshowed that the maximum steady state heatloss was three kilowatts when it was minusten outside, so we knew that we had to pro-vide a heat source that worst case scenariowould provide three kilowatts.”

A room-sealed wood burning stove in the livingroom provides approximately the required threekilowatts, but a back-up heat source was stillneeded. McAlister’s first solution was to installa small underfloor heating system connectedto an air source heat pump, but because the

capital cost of the underfloor heating came inclose to £7,000, the budget wouldn’t allow it.“In the end, we decided to install direct elec-tric radiators. They’re not in yet, but insteadof costing £7,000, they cost £500. We havesix kilowatts of direct electric which we hopewe never need. But they’ll be there there if wedo.”

A heat pump was nonetheless installed – anexhaust air heat pump, which forms part of anintegrated heating, ventilation and hot watersolution, heating towel rails in the home’s twoen suite bathrooms and contributing to do-mestic hot water supply. The heat pump hascontrols in place to source the warmest air atany given time – whether from external air, fromthe extract from the MVHR system, or fromthe ventilated loft in the summer. How water isprovided primarily by four square metres ofsolar thermal panels feeding into a 300 litredomestic hot water cylinder. According to re-newable heating provider Solmatix, the solar willgenerate free hot water for six to eight monthsof the year with the heat pump taking overduring the winter to provide cheap hot water.

The McGlinchey’s have now been in the housesince May – with the house wired for directelectric radiators that haven’t yet been installed– and so far, so good.

“There’s going to be a bit of a learning curve,”says Paul McAlister. “but they’re really pleased.What we really need now is to see how it performsin the winter�”

SELECTED PROJECT DETAILSArchitect: Paul McAlister ArchitectsPassive house certification:Passive House AcademyMain contractor: Baylands ConstructionAirtightness tester: Airtightness IrelandBuild system supplier: SipfitAdditional wall & roof insulation: RockwoolFloor insulation: Kingspan SpringvaleThermal blocks: FoamglasAirtightness products: Pro Clima/VarioWindows & doors: Munster JoineryRoof lights: VeluxZinc /aluminium cladding:Rowan Roofing CompanySteel web floor joists: Haldane FisherHeat recovery ventilation: Pure Renewable EnergyRenewable heating system: Solmatix RenewablesStove: All Fired Up Stoves �

new build

(above) Erection of the structural insulated panel system, which facilitates eliminating cold bridges, because the system creates a continuous thermal envelopethrough walls and roof; (bottom right) a triple-glazed Velux roof window allows extra light into the house; (bottom left) the steel web floor joists house buildingservices such as MVHR ductwork discretely

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new build

PROJECT OVERVIEW:

Building type: 185 sq m detached two-storeypassive house

Location: Bangor, Northern Ireland

Completion date: April, 2013

Budget: £192,000

Passive house certification: certified

Space heating demand: 14 kWh/m2/yr

Heat load: 11 W/m2

Primary energy demand: 91 kWh/m2/yrtotal demand on heating installation, domestichot water, household electricity and auxiliaryelectricity calculated according to PHPP.

Airtightness (at 50 Pascals): 0.6 ACH

Energy performance certificate (EPC): A-92

Thermal bridging: first two courses of Foam-glas Perinsul SL, thermally broken windowframes, insulated reveals.

Ground floor: solid slab. 100mm screed; 200mmSpringvale Platinum EPS; 150mm concretesub floor. U-value: 0.144

First floor: contains Posi-Joist open web floorsystem to house building services includingventilation ductwork.

Walls: Sip panels. 20mm render, cement andsand; 100mm concrete block outer leaf; 50mmunventilated air layer; 1mm breather mem-brane; 12mm oriented strand board (OSB);200mm polyurethane insulation; 12mm OSB;1mm Pro Clima DA airtightness membrane;insulated service cavity; 13mm plasterboard.U-value: 0.11

Roof: natural slates externally on 50x35mmbattens/counter battens; 1mm Juta Trim Easybreathable roofing underlay; 12mm OSB;200mm polyurethane insulation; 12mm OSB;1mm Pro Clima DA airtightness membrane;insulated service cavity; 13mm plasterboard.U-value: 0.11

Windows: triple-glazed Munster JoineryPassiv Future Proof PVC windows, withargon filling. Overall U-value: 0.78

Roof windows: triple glazed Velux roof windowwith a recessed flashing kit. U-value: 0.82

Heating & hot water: 4kW Rika Vitra PassiveHouse wood log burning stove, room sealed.Back up space heating to towel rails and do-mestic hot water is provided by a SolmatixX3 Combi air source heat pump with a COPof 3.68, based on EN 14511-2, with controlsto prioritise take air supply from external,MVHR extract, or ventilated loft subject toair temperature. 300 l domestic hot watercylinder. 4 sq m Solmatix solar thermal arrayto provide domestic hot water in conjunctionwith heat pump.

Ventilation: Paul Novus 300 heat recoveryventilation system — Passive House Institutecertified to have heat recovery rate of 93%

ph+ 49

Artist Rob Davies and his wife Amy Staniforthdidn't set out to build a passive house. "We werejust aiming for something that would keep uswarm and wouldn't cost the earth," Rob says.

The couple started looking for a plot a fewyears ago, before they got married. Rob wasliving in Worcestershire, where he'd built hisown studio. Amy was working at AberystwythUniversity in west Wales.

They looked at sites in both locations, andhalf-way between, but ultimately decided tosettle in Tre-Taliesin, near Aberystwyth. "Aslong as I've got a studio I can work anywherebasically," Rob says.

They bought a site, and Rob started sketchingdesigns for the house. They both wanted to maximiseviews facing north west to the sea and hills.

"I kept drawing the house with Amy, and imaginingwhat it would be like living there, and imagining whatit would be like to work there," Rob says.

If you keep doing that over and over again, hesays, and keep making mistakes, you eventuallyget it right.

"We were interested in the process, so we wentthrough it ourselves rather than just giving it toan architect. We could have designed a muchflashier building, but we just wanted it to work."

One of the early design challenges was posedby the couple's two dogs and two cats. "We hadto design the house so they could co-exist butnot meet each other."

Rob and Amy had already secured "reservedmatters" planning permission when they metlocal heat pump engineer John Cantor, whorecommended they talk with passive housedesigner Nick Grant. Rob called him, and Nickagreed to come on board as passive houseconsultant.

Rob decided to act as project manager. "I thinkin a way that's not such a bad thing if you'respending your own money," he says.

He hired architects Daffyd Tamos to help makehis designs a reality, and appointed local firmTai Dyfi as the contractor. Rob and Amy knewfrom the start that they wanted a timber house— not just a home built from timber, but cladwith it too.

And indeed wood is at the heart of the structure:the walls are timber frame, they're insulatedwith 350mm of Warmcel, and clad with Welshred cedar weatherboard. Airtightness is providedby a Pro Clima Solitex DA membrane, suppliedby the Green Building Store.

The roof features 400mm Warmcel-insulatedSteico rafters, and a Solitex membrane forairtightness.

Powys-based company PYC Insulation (formerlyPen y Coed) installed the Warmcel insulation,while their sister company PYC Systems carriedout the final airtightness test, which produceda result of 0.365 ACH — an improvement ofaround 22% on the first test result.

"The second tests were carried out after secondfix, but we believe that the main reason for theimproved score is the full-fill of Warmcel," saysPYC's Rich Herbert. "We have carried out othertests over the years and have come up with verysimilar results."

The windows are Optiwin Alu2wood triple-glazedunits, which were supplied by the Green Build-ing store and have an overall U-value of 0.77.

Not every site lends itself towards passive house, or so the story goes. Intent on making the most of spectacularviews to the northwest, Rob Davies and Amy Staniforth’s ecological self-build shows that passive housecan overcome orientations that turn their back on the sun.


NORTHWEST facing home

shows passive flexibility

But when it came to sealing the building en-velope the pets again posed a challenge: howdo you make a cat flap airtight?

For Rob, the answer was to make one him-self: a simple box with a flap on either endthat's surrounded by insulation and taped inplace. Rob had seen an airtight cat flap on-line for $1,000, but his version cost just £25.

"One of the cats, Parsnip, she actually sleepsin it," he says.

Mike Neate of ECO DC, airtightness consult-ant and window fitter on the project, saysthere was a substantial difference betweenthe pressurisation and depressurisation re-sults on the first airtightness test. This is be-cause during depressurisation, membranesand tapes are "sucked" against the buildingstructure, improving the seal. This helped theteam diagnose a leak at one window box.

One gable wall was built too high during con-struction. Mike Neate says this would have ledto thermal bridging where the gable structuralstud passes through the roof insulation zone, andwould have been tricky to seal for airtight-ness, so the height of the wall was lowered.

Rob says one of the best decisions he madewas getting the whole project team togetherfor a planning session twice prior to the buildcommencing to hammer out any issues.

"I guess that really did help, because the buildwent smooth," he says. “The contractor or hisguys turned up every day of the build at 8am andleft at 5pm and were very conscientious in theirwork, even though it rained almost every daythey were on site.”

Rob looked into all sorts of ways to heat the house.There's no gas network in the area, and he didn'twant to store fuel on site either. He was alsokeen for the heating to be as automated as pos-sible, so he ultimately plumped for a groundsource heat pump, supplied and installed byJohn Cantor.

"The first decision was between a high and lowtemperature range heat pump," John says.Rob went for a high temperature unit because,in a passive house, hot water rather thanspace heating is the biggest load.

"The second decision was buffer cylinder orno buffer cylinder. Since space was limited,we decided to use the floor screed as a buffer.

This provides enough mass to absorb heat andminimise cycling of the compressor,” John says.

To aid buffering, 900 metres of underfloorheating pipe was laid down under the pol-ished concrete floor. Extra underfloor heatingwas installed in the downstairs wet room andthe studio, in which he works all year roundand is single storey. Rob and Amy helpedJohn install the pipework.

There's also a twin-coil 260 litre Newark CopperCylinder for hot water, fed by the heat pump

and two Velux roof-integrated solar panels,supplied by local firm Llani Solar.

The team decided to remove all but one ther-mostat from the house for the first year as anexperiment. They'll monitor the performanceof the house closely for 12 months, then de-cide what kind of control setup will work best. "The house is mostly open plan, and being apassive house, the rooms tend to equalise,"John Cantor says, "in part due to the self-reg-ulating effect of underfloor heating in such awell-insulated house." �

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"The house is such a fantasticpleasure to be in. I'm sitting at awindow now looking out towardsthe sea. It's been 20.5 degreesor above for the 8 months we'vebeen here."

(below) Various stages of the wall build-up showing, from left, the Solitex DA membrane; the larsen truss; the Hunton Sarket fibreboards; airtight tapes to cover cellulosedrill holes in the fibre board; (p53, clockwise from top left) 900 meters of underfloor heating pipework was laid; the timber frame taking shape; an airtight catflap,built by the client for just £25; the windows were installed proud of the main timber frame, to form a complete insulation layer once cellulose is added

ph+ 51

The house has a 3.4kW solar PV array too,also supplied and installed by Llani Solar. Atthe time of writing it has produced just under3,000 units of electricity — compared to 1,000consumed by the house.

At one stage Rob considered ditching the PV

to save money, but ultimately put it in. He'snot regretting the decision. "You feel likeyou're making less of a mess of the world," hesays. "Now we're really pleased with it."

He's happy with the solar thermal too. "It’s lovelyto think you can have a hot bath or whatever,

and there's no cost."

Nick Grant says when he came on board, meet-ing the passive house standard didn't lookfeasible. A mountain to the south east reducessolar gain, and there’s glazing to the north —not ideal for maximising passive gains. �

new build

ph+ 53

But on the other hand, the house has excel-lent airtightness and a decent surface-to-volume ratio to its advantage. The wall androof U-values are also superb.

The design heat load is 10 W/m2, while the spaceheating demand is 14 kwH/m2/yr, meaning thedesign meets the passive house standardeven though Rob isn't looking for certification.

"Overall I think it is a lovely building and I lookforward to return visits as it settles into thelandscape," Nick Grant says.

Almost as soon as Rob and Amy moved in,west Wales experienced a spring freeze."Con-sidering the plaster had only been on the wallsa few weeks, and the concrete still hadn't driedout, it was amazing," Rob says.

"The house is such a fantastic pleasure to bein. I'm sitting at a window now looking out to-wards the sea. It's been 20.5 degrees orabove for the eight months we've been here."

Rob says his 88 year old father, who was abuilder himself, had told him: "You don't build yourown house, you build other peoples' houses."

But then he came to see it. "It was great, theywere really blown away. My dad said to me ‘Ican't believe you took this on, but it's really

good’. And I was dead chuffed."

SELECTED PROJECT DETAILSClients: Rob Davies and Amy StaniforthArchitects: Daffyd TamosM&E consultant: Alan ClarkeCivil & structural engineering:Bob Johnson Consulting Structural EngineersPassive house consultant: Elemental SolutionsContractor: Tai DyfiHeat pump design: John Cantor Heat PumpsHeat pump: Kensa Heat PumpsAirtightness consultant & window installer:ECO DCCellulose insulation & airtightness contractor: PYC InsulationCellulose insulation: WarmcelAirtightness products: Pro Clima, via Green Building StoreWindows & doors: Optiwin, via Green Building StoreSolar thermal & PV: Velux/ET Solar, via Llani SolarOSB: NorbordRafters: SteicoSarking boards: Hunton Sarket






new build

PROJECT OVERVIEW:

Building type: 210 square metre detachedtwo-storey timber frame house with singlestorey studio attached.

Location: Tre Taliesin, Nr Machynlleth,Ceredigion, Wales

Completion date: February 2013

Budget:Build £290K (£375K including purchaseof land)

Passive house certification: Not sought

Space heating demand (PHPP): 14kWH/m2/yr

Heat load (PHPP): 10kWh/m2/yr

Primary energy demand (PHPP): 74kWh/m2/yr

Airtightness (at 50 Pascals): 0.365 ACH

Energy performance certificate (EPC): A 97

Ground floor: 50mm sand at bottom, followedabove my 250mm EPS, 300 micron Radonscreen, 250mm C35 concrete reinforced by10mm steel (200x100mm), powerfloated thenpolished. U-value: 0.135

Walls: 20mm welsh red cedar weatherboardon 25x50mm vertical battens against 18mmHunton Sarket board on the outside of 350mmdeep Warmcel-insulated larsen truss (with 9mmfin) then Solitex DA airtightness membrane,11 mm OSB sheathing on 89x50mm studframe with full quilt insulation then 12.5mmplasterboard and skim. U-value: 0.095

Roof: Cupa R4 natural slates fixed with coppernails on 25x50mm s/w battens on 50x50mmcounter battens sitting on 18mm Hunton sarketboard glued and screwed to rafters. 400mmdeep Steico rafters filled with Warmcel on12 mm OSB to underside of rafters. ProclimaDA membrane taped with Tescon Vana then25x50mm battens and 12.5mm plasterboard(not foil backed). U-value: 0.099

Windows: Optiwin Alu2wood triple-glazed,argon filled, timber internal aluminium externalwindows supplied by Green Building Storewith overall. U-value: 0.77 W/m2K

Heating system: Kensa KR4190 3.5kW singlecompressor high temperature heat pumpdrawing from 400 sq m of horizontal collectorswith 900m of armoured underfloor heatingpipe set in the raft concrete foundation runningat 23C. 260 L hot water tank with two VeluxU12 solar thermal collectors totalling 5 sq m.

Ventilation: Paul Novus 300 MVHR, with aPassive House Institute certified efficiencyof 89%

Electricity: 18 sq m ET 660 solar PV arraywith annual output of 3.3 kW

Green materials: cellulose insulation, HuntonSarket board, Steico rafters

ph+ 55

We tend to think the worst examples of socialhousing — decaying tower blocks, huge isolatedestates — are from the past. But just how goodis the social housing we’re building today?

Energy consultant Andrew Fisher says becausebudgets for social housing projects are typi-cally low, corners are often cut. "Typically so-cial housing is deemed to be 'house bashing'with little need [for] skill and finesse," he says.

"It typically seems to be done at such a low cost— because there's very little money — thatquality slips.” This means the cheapest materialsare chosen, and the price paid to subcontractorsis pushed down.

Fisher played a big role in the construction ofa four-unit passive social housing developmentin the village of Fulmodeston, Norfolk, in hisprevious role as sustainability manager at

contractor Lovell. He has since left to start hisown consultancy, AMF Consulting.

He says that passive house, “forces trades todo the job correctly, and this was evident atFulmodeston by the result.”

The scheme was developed by the BroadlandHousing Group, who were gifted the site bylocal landowner Lord Hastings. North Norfolk

Social schemefinds value in passive

With social housing tenants let down by substandard energy efficiency requirements under UK buildingregulations, some switched-on housing associations are taking matters into their own hands and buildingto the passive house standard. Broadland’s first certified passive scheme in Norfolk is a significantstep on one association’s journey towards social housing fit for the 21st century.


suffers from high levels of fuel poverty due tothe lack of a gas network, old housing stock,and low incomes.

Broadland's head of development Ed Mumford-Smith says that before Fulmodeston, the grouphad built schemes to levels three and four of theCode for Sustainable Homes with mixed results.The more successful projects tended to be thosewith a ‘fabric first’ approach that focused oninsulation rather than bolt-on technologies.

Fulmodeston presented a good opportunity forthe association to build its first passive housescheme, ahead of a planned 250 unit passiveapartment development on Norwich’s CarrowRoad due to commence in 2014. Broadlandplanned the project alongside a similar devel-opment in Barney, the neighbouring village.The latter scheme was designed to get close

to — but not quite reach — the passive housestandard.

“It was also an experiment to see how thosehouses [at Barney] performed against passivehouse standards,” says Ian Bramwell of MoleArchitects, who designed both schemes.

Mole had been approached directly by Lord Hastings,who admired the firm’s work, particularly on theirbarn-inspired Black House in Cambridgeshire.

The design at Fulmodeston is partially inspiredby the village’s existing 1950s social housing.The new scheme’s black roof tiles are alsoparticular to this part of Norfolk.

Having worked extensively in timber frame,this was the natural choice of building mate-rial for Mole. The walls at Fulmodeston are in-

sulated with 235mm of polystyrene bead, withan additional insulated service cavity of 45mm.

In the attics there’s 500mm of Knauf EarthwoolLoft Roll 40 on the flat between the joists,while in some areas the first floor ceiling ishipped and there’s Knauf’s Rafter Roll 32 be-tween the rafters. Both insulation products weresupplied by the Mark Group. The groundfloors feature 200mm of Celotex PIR insulation,while the windows are Passive House Insti-tute certified timber-aluminium Internorm HF300 Edition units, supplied and fitted by Eco-Haus Internorm.

Marmox Thermoblock was used under doorthresholds to prevent thermal bridging here.Thermoblock is an insulating, load-bearingblock composed of a rigid epoxy-concrete frameintegrated with an XPS core. �

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ph+ 57

In the walls and rafters, airtightness is providedby a Pro Clima Intello Plus membrane, whichwas supplied by Irish company EcologicalBuilding Systems. All four units beat the pas-sive house airtightness standard of 0.6 ACH.

Ed Mumford-Smith says the project involved"a lot of quality control, and a lot of commit-ment." About 300 inductions were carried outto teach staff the principles of passive house.

Heating, if needed, is provided by a singleDimplex electric storage heater in each house,and a single towel radiator in the bathrooms."When you look at the passive house buildingphysics, it's about getting the heating demandso low that you don't need a heating system,"says Ed Mumford-Smith. But additional fusedspur points have been installed so further electricpanels can be installed if needed.

“The design team ensured that the design wasmodelled in detail at a very early stage to ensurethat we would have comfort in the heat de-mand and heat load,” says Andrew Holmes ofALH Design, M&E consultants on the project.

Each house also has a single three-square metreViridian Clearline V30 solar thermal panel,connected to a 210 litre solar cylinder, withback-up immersion. Ventilation is provided byZehnder ComfoAir 200 Passive House Insti-tute certified heat recovery ventilation units,which boast 92% heat recovery efficiency.

Tenants started moving into the Fulmodestonscheme at the end of July. When Passive HousePlus spoke to resident Claire Murdoch in October,she said temperatures inside had been aver-aging 21C or 22C. “Sometimes it gets a bit coolerif we've been out and there's no appliances on.”

She had yet to use either her electric panelheater or towel radiator. The only real learningcurve, she said, is knowing when to turn on theback-up immersion.

"Sometimes the weather isn't as good and wedon't have as much hot water, so we've got aback-up immersion. That's the thing I'm still get-ting my head around at the moment.”

She notices heat traveling around the wholehouse after cooking or baking far more in hernew house. Her electricity bills had averaged£30 a month until October. Overheating hasn'tbeen a problem either. “Even when we had

the hot weather, the temperature inside, par-ticularly upstairs, was really cool.” The housesare fitted with brise soleil on the south facade.

Broadland Housing are now monitoring electricityuse, as well as internal and external temper-atures at both the Fulmodeston and Barneydevelopments. Ed Mumford-Smith says mostteething issues usually arise at rural develop-ments where there's no gas network. But thisisn't the case with Fulmodeston or Barney."Usually no news is good news,” he says.

Based on their monitoring so far, Broadland mayadd one more electric panel heater to one ofthe units.

Project architect Ian Bramwell credits AndrewFisher with the success of the building. “Hewas on site many days with tape in his handgoing around checking for holes. Without Andy,it wouldn’t have met the passive house stan-dard for sure,” Ian says.

Perhaps one reason for Fulmodeston's suc-cess is the alternative approach the team tookto contracting. Rather than a contractor beingchosen through competitive tender, the processwas more collaborative: Lovell was chosenfor their team and expertise, then a price wasnegotiated. Lovell separately interviewed itsown subcontractors to gauge their ability todeliver the project.

Andrew Fisher reckons this approach is far moresuited to the rigorous demands of passive houseconstruction: he says that negotiations musttake place early on, before a price has beenfixed — everyone must sit down and decide whatthe project’s goals are and how to achieve them.

“If I was a housing association that's how I woulddo my business," he says. "I wouldn't put it outto tender."

Passive house doesn't need to be complicated orcostly, he says, but clients must be willing to paythe true cost. Equally, subcontractors can't as-sume that items can be "value engineered" out,or work artificially hastened during the build.

"In my opinion we don't allow our trades enoughtime to do the job properly," he says. "This is whyI think we have the performance gap in the UK."

At Fulmodeston, subcontractors were paidper day rather than an overall fixed price —

to make sure they had the time to do theirwork thoroughly. Naturally, this required tightmanagement on site.

"You need trusted subcontractors, and youneed a good site team," Fisher says. "Mostpeople actually want to get on with the work,they don't want to dilly-dally around. We neversaw any evidence of time wasting."

“We had a very, very tight budget. We had tothink on our feet and box a bit clever.”

Andrew says one of the big challenges for theproject was the lack of a local supply chain forpassive house. It was hard to find companieswilling to spend on R&D at the time, he says— particularly for such a small development.

But he thinks this is changing. “The mindset isnow there. The number of housing associationsthat are specifically requesting passive househas grown.”

“The market is seeing an interest and starting tolisten and sit up. It’s interesting and encouragingat the same time.”

Broadland Housing’s Ed Mumford-Smith saysthat following the experience gained from thegroup’s first passive house scheme, they’rehoping to do more passive projects in the future,including the Carrow Road development.

"The end goal is about delivering low energyhousing that people will want to live in,” he says.

SELECTED PROJECT DETAILSClient: Broadland HousingArchitect: Mole ArchitectsM&E Consultant: ALH DesignCivil & structural engineer: Rossi LongContractor: Lovell PartnershipsEnergy consultant & project management: Lovell PartnershipsQuantity surveyors: David LangdonMechanical contractors: J&T PlumbersElectrical contractor: Alpha ElectricalAirtightness consultant: Lovell PartnershipsAdditional wall insulation: Norfolk DrywallThermal breaks: MarmoxRoof insulation: Mark GroupAirtightness products: Mark GroupWindows & doors: Ecohaus InternormRoof lights: Fakro GBPrimary heating: Dimplex storage heatersVentilation: Zehnder Comfo SystemsSolar thermal: Viridian Solar �

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new build

PROJECT OVERVIEW:

Building type: four unit development ofsemi-detached, timber frame passive houses

Location: Fulmodeston, Norfolk

Size: each unit 96 square metre approx

Completion date: July 2013

Budget: £530,000 for all four units

Passive house certification: certified

Space heating demand (PHPP): 12 kWh/m2/yr


Primary energy demand (PHPP): 87 kWh/m2/yr

Environmental assessment method: Codefor Sustainable Homes Level 2

Airtightness (at 50 Pascals): Average of0.6 air changes per hour

Ground floor: 65mm concrete screed with200mm Celotex PIR insulation underneath.U-value: 0.107

Walls: 9mm OSB on the outside of the thermalenvelope, followed inside by 235mm EPSbead insulation, 9mm OSB, 25mm unventedcavity, 45mm insulated service cavity, 15mmplasterboard. U-value: 0.109

Flat roof section: 500mm Knauf EarthwoolLoft Roll 40 (100mm between joists, 400mmover) over uninsulated 50mm service cavitywith 13mm plasterboard beneath. U-value 0.08

Sloped ceiling (north): 175mm Knauf RafterRoll 32 insulation between the rafters, with afurther 80mm of Rafter Roll over the rafters,and covered with 13mm plasterboard. U-value:0.116 W/m2K

Sloped ceiling (south): 27mm ventilatedcavity outside of 170mm rafters insulatedwith Knauf Rafter Roll 32, with a further 40mmof Knauf Rafter Roll 32 covering the rafters,followed inside by 25mm service cavity,45mm Ecotherm rigid PIR insulation, 15mmplasterboard. U-value: 0.112

Windows: Internorm HF 300 Edition timberaluminium triple-glazed units, PHI certified.Average overall U-value: 0.69

Roof windows: PHI certified Fakro quadruple-glazed FTT U8 Thermo roof windows. U-value: 0.58

Heating system: 1 x Dimplex electric storageheater and 1 x towel radiator in each unit. 3 sq mViridian Clearline V30 solar thermal panelconnected to 210 litre twin immersion tankwith 50/50 solar/electric volume.

Ventilation: PHI certified Zehnder ComfoAir200 heat recovery ventilation system in eachunit. 92% heat recovery efficiency

Green materials: Timber frame, recycledmineral wool insulation

“The number of housing associationsthat are specifically requesting passivehouse has grown. The market is startingto listen and sit up.”

(top) The houses are fitted with brise soleil on the south facade to prevent overheating; (bottom right)Pro Clima tapes help achieve high levels of airtightness; (bottom left) a blower door test in progressto measure the air leakages in the building; (p59) windows and doors are Internorm PHI certifiedtriple-glazed units, and the houses also feature quadruple-glazed Fakro roof windows to illuminate stairwells

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DUBLINHOME

reborn with Enerphit upgrade

4

While the passive house standardis long established in Ireland andthe UK, the comparatively newequivalent for retrofits, Enerphit,is still in its infancy. In spite of adauntingly complex and crumblingexisting building, a detached housein Donnybrook has been modernisedto become Ireland’s 2nd certifiedEnerphit building.

Words: John Hearne

If this project proves nothing else, it’s that passivestandards can be achieved in the most un-likely situations. The decision to go for Enerphitdidn’t come until after planning permission hadbeen granted. This put serious limitations on theamount of reworking that could be done inorder to achieve the higher thermal perform-ance. In addition, the client had set out pre-cise specifications for the internal layout ofthe house which were non-negotiable. Therewere the inevitable budgetary restrictions andwith the south side of the house facing ontothe street, even the orientation was wrong.Add to that the normal challenges of deepretrofit, this Dublin suburban Enerphit projectrepresents a remarkable achievement for boththe design and construction teams.

“The client has a large family and very specificdesign requirements,” says Archie O’Donnell ofIntegrated Energy, who was energy consultant onthe project. “They wanted open plan living, theywanted lots of light and they wanted to open upthe garden.” Because the existing house fell far shortof what was required, demolition would havebeen the first choice, but planning restrictions

required an element of retention on the project.

“It was only really during the detailed designstage when we were putting together the ten-der documents that the client decided to aimfor the Enerphit standard,” says architect AlanBurns of Bright Design Architects. “Obviously,it would have been a lot better if this decisionhad come pre planning. With the south facingorientation on the streetscape, we would haveredesigned the facade both on the south andthe north to reflect this, and we would haveincluded a bit more shading. Also, we had setcertain window sizes and configurations anddid not have the option to change them.”

It was design with one arm tied behind yourback. And the biggest challenge, everyone knew,would be airtightness. The house had beenextended many times over the years, whichmeant that there were a variety of wall types,including nine inch hollow block and cavity wall,with some brick faced fronts. There were particularconcerns about air infiltration in the rising walls.

Though the client would have liked to retain

some of the internal walls and existing timberfloor, he conceded that these would have to beremoved in order to facilitate the airtightnessstrategy.

Even at that, it was felt at tender stage that whileall other Enerphit criteria could be met, the airchange rate of 1 ACH would be a bridge toofar. For that reason, the tender documentsspecified a slightly higher air change rate inorder to protect the budget. Cyril Mannion ofPassive House Builders won the tender, andthough he had no contractual obligation, henonetheless committed to achieving the Enerphitairtightness standard at the existing budget.

Archie O’Donnell says that at the beginning,the plan was to retain as much of the existingbuilding as possible. “That would have includedall of the outer four walls and the first floor timbers,but on investigation it was found that becauseof extensions over the years and because ofthe use of a lot of hollow block, the rear wallwas in a bad state and couldn’t be retained.On top of that, the timber joists were damagedat the end grain, and they had to be replaced.” �

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(above) The clients wanted a bright spacious open plan design, as evident by this photo of the main living area, which opens up to the garden (below) through thelarge glazed areas that allow plenty of light into the house; (p65, main picture) bespoke roof windows introduce additional heat and light into the core of the house,down through the stairwell

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The reality was that the existing structure wasnot fit for purpose and ultimately only the bareminimum could be retained. “We were left withthis skeleton of a house,” says Cyril Mannion. “Tobe honest we were nearly afraid it would fall,so we were tiptoeing around that for a whileuntil we got it back up again.” Deemed un-savable, the left hand gable was demolishedand rebuilt, with two courses of low thermalconductivity Quinn Lite blocks used to reducecold bridging at DPC level.

While the structure was dry, the internal facesof walls had considerable mould growth inbathrooms and some bedrooms to the north

of the house due to surface condensation.

The form of the building was driven largely byplanning constraints and the client’s require-ments. But though the passive imperative mayhave arrived post planning, Bright Design’splan had in any case embodied many low energyprinciples. A dual aspect living space neatlycaptures solar gains from the south facing street,while a terrace in the front garden helps keep thatspace private and informal. In addition, the glazingstrategy had also taken account of maximisingsolar gains without risking overheating. Roofglazing, for example, introduced heat and lightinto the core of the house via a stair course. �

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“We were left with this skeletonof a house. To be honest we werenearly afraid it would fall”

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Archie O’Donnell explains that with so manydesign elements fixed, he concentrated muchof his efforts on the building fabric. “We wouldrather put the performance into the solid as-pects, so overcompensate on walls, roofs andfloors and then be able to reduce the spec onthe high variable cost items; things like windows.”While the windows are very high quality; triple-glazed and featuring class four airtightness,they are not thermally-broken passive certi-fied units. The insulation strategy, as with somany deep retrofits, centred on wrapping thebuilding in a thick, continuous layer of externalinsulation. According to window supplier BrianRaftery of True Windows, the company pridesitself on the airtightness of its installations. “Intoday’s built environment, the discerning clientsare looking to a standard of 0.6 ACH for theirbuilding. The material we install meets this re-quirement time after time.”

One of the most critical elements of the buildlay in detailing the myriad junctions in orderto deliver both the right aesthetic and the rightthermal performance. Archie O’Donnell of In-tegrated Energy and Alan Burns of Bright Designdrew up more than 24 separate constructiondetails before the project went to tender. “Therewas a huge amount of time spent thinking aboutit and working it out,” says O’Donnell. “Therewere very complex junctions with roofs, withexisting walls to new walls and new thresh-olds with existing thresholds...It was the kindof thing that you must think out completely be-fore you hit the site.”

It was a painstaking, iterative process. The architectmight begin with a detail of what he wantedto achieve aesthetically and the energy con-sultant would then add details on insulationand airtightness. These drawings were sharedin the cloud, moving back and forth betweenthem until each was agreed and finalised.

The detailing also captured how airtightnesswas to be achieved. While Intello membraneswere specified as both airtightness layer andvapour check, again, the complex series ofjunctions in the house required detailed spec-ification by the design professionals. And on-site, because airtightness is about process as

much as product, delivering results requiredclose attention to detail. Cyril Mannion erecteda sign in the kitchen: ‘This is an airtight buildingwith underfloor heating. No drilling.’

Mark Shirley of 2eva performed two airtightnesstests on the house. The first result came in at0.7 ACH, well inside the Enerphit standard.“If we had done nothing else with it,” he says,“that would have been an exceptionally goodresult because the building is large and ar-chitecturally complex.” He points out that ex-perience is key to getting a good airtightnessresult, and notes that the more projects a builderhas worked on, the less materials he needsto achieve a set target.

The second test hit 0.63 ACH, which Shirleypoints out is on the cusp of full passive. “That’sa 10 per cent improvement between first fixand final test...To have an Enerphit projectinto the realms of a new build passive houseis quite exceptional.”

According to lighting designer Rocky Wall ofWink Lighting, the lighting design was drivenby energy efficiency without compromising onaesthetics. “The net result is a super-efficientlighting system that compliments the archi-tecture of the building,” says Wall, adding thatdownlighters were kept to a minimum to avoidcompromising the airtight layer. “Also down-lighters are a very poor light source,” says Wall.“They were really only designed to highlightan object or a feature. They became fashionablebecause of their physical size as opposed totheir illuminating ability.” Instead the lightingstrategy relies predominantly on LEDs andfluorescent lamps, including innovative dim-mable LED wall lights.

Mechanical contractors Noel Geraghty Heating& Plumbing were responsible for installing theheating, plumbing, BEAM MVHR and centralvacuum systems, solar thermal and rain waterharvesting systems throughout the building.Given the stringent airtightness target of 1ACH that the project had to hit, it was criticalthat all of the sustainable mechanical systemsinstalled operated cohesively together with-out compromising the precious airtight layer.

“There was very close coordination betweenthe architects, consulting engineers, Cyril Mannionand the mechanical and electrical contrac-tors to ensure that airtightness wasn’t com-promised,” says Noel Geraghty, who has over20 years experience in domestic, industrialand commercial installations. Service voidswere built within the airtight layer with the mainservice penetrations entering the building via thesub floor. “We’re very proud to have been partof this project and delighted to have contributedto its certification.”

Ventilation required quite a bit of design work.It was decided that the house would be dividedinto two separate regions, each with its ownMVHR unit, extracting and supplying the roomsin its half.

“The client was very particular about his acousticrequirements,” says Alan Burns. “He didn’t wantsound transfer within reason between bedroomsand the hall, or between bedrooms and eachother.”

In order to achieve this, the bedrooms werefitted with drop-down acoustic seals, whichwere automatically lowered from within thedoor leaf when the door was closed. Whilethis achieved the acoustic separation the clientwanted, it interfered with the passage of air thatthe ventilation strategy required. In response,it was decided to extract and supply to eachroom individually, or, in the case of en suites,to extract from en suite and supply to its ad-joining bedroom. Extra ducting was requiredto make this work, with additional acoustic at-tenuators to limit sound transfer via the MVHRsystem. There were also knock-on effects onthe Enerphit calculations. The use of two sys-tems required additional energy, which wascompensated for by improvements to the fab-ric, and of course the better than expected air-tightness performance.

But because all of these issues were modelledand thoroughly dealt with during the planningstage, the build itself progressed very smoothly.Contractor Cyril Mannion reports an overrun of �

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just three days. “It was all well planned,” he says,“there were no major problems, no major hiccups.”

SELECTED PROJECT DETAILS Client: privateArchitect: Bright Design ArchitectsM & E engineer: Ramsay Cox & AssociatesCivil / structural engineer:Barrett Mahony Consulting EngineersEnergy consultant: Integrated EnergyMain contractor: Passive House BuildersClient's representative: McCarthy & AssociatesQuantity surveyors: Duffy Gaffney PartnershipLandscape gardening: DoylescapesMechanical contractor: Noel Geraghty Heating & PlumbingElectrical contractor: CTS ElectricalAirtightness tester/consultant: 2eva.ieExternal insulation system: StoBelow DPC wall insulation: Kingspan AerobordSarking board & floor insulation: XtrathermGlass fibre insulation: IsoverFlat roof felt & insulation: Moy MaterialsCellulose insulation: WarmcelCellulose insulation installer: EcowiseThermal blocks: Quinn Lite

Airtightness products:Ecological Building Systems/AlfaWindows & doors: True WindowsRoof lights: RuhmGGBS: EcocemCondensing boiler: Worcester BoschSolar array: Kingspan RenewablesRoom sealed gas fires: Heating distributorsUnderfloor heating & solar subcontractor:Base EngineeringUnderfloor heating system: Hevac MVHR & central vacuum syustem: Beam Central SystemsLighting design: Wink LightingRainwater harvesting: Kingspan Environmental






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PROJECT OVERVIEW:

Building type: 367 sq m renovation and extension to a 1960s detached house

Location: Donnybrook, Dublin 4

Completion date: September 2013

Budget: not disclosed

Enerphit certification: certified

Space heating demand (PHPP): 21 kWh/m2/yr


Primary energy demand (PHPP): 109 kWh/m2/yr

Energy costs

Before: heating and hot water bills had been €4-5,000 per annum – and the building wasn’t able tomaintain 18C during the heating season. After: an estimated total for heating/hot water of circa 8800/2700 kWh, totalling circa €850 per annum.

Airtightness (at 50 Pascals): 0.63 air changes per hour

Original walls: a combination of uninsulated cavity wall and single leaf nine inch hollow block walls.Upgraded/extension walls: Acrylic render finish on 200mm White EPS 90 insulation fixed to existingstructure or to 215mm new blockwork walls. Hard plaster scratch coat to internal face of walls, 38mmbattened service void with 12.5mm skimmed plasterboard finish. U-value: 0.17

Original ground floors: suspended timber floors, uninsulated.Upgraded & extension ground floor: timber floor on 75mm screed with underfloor heating on160mm PIR insulation on 200mm reinforced concrete slab on continuous radon barrier / DPM lappedand sealed on sand blinding on hardcore. U-value: 0.131

Original roof: cut timber roof with circa 100mm fibre glass insulation on attic floor.New roof: Roadstone mini-slate concrete roof tiles fixed to treated battens, on a Pro clima SolitexPlus waterproof membrane over counter battens, on 60mm Xtratherm XT sarking board on timberjoists [11%] on 225mm Metac glass fibre insulation. Continuous Intello airtight membrane taped andsealed with Pro Clima Tescon tape to underside of joists, with 60mm service void filled with Metacbetween battens. U-value: 0.115

Flanking roofs: as above on slope except with 175mm rafter, no plasterboard and no service cavity.Flat of flanking roofs includes Paralon roofing felt and 120mm of Paratorch insulation; 225 celluloseand Intello airtightness membrane. Slopes of flanking roofs include 80mm Xtratherm sarking board,and 175mm pumped Warmcel celluloseinsulation, and Intello airtight membrane.

Original windows & doors: double-glazed PVC windows, glazed hardwood front door and double-glazed hardwood windows and doors to rear utility.New triple-glazed windows: HolzPlus timber aluclad frames with IV 78 windows and doors, class fourfor airtightness. Glass U-value of 0.6. Frame U-value for fixed unit: 1.0 Frame U-value for opening unit: 1.1

Roof windows: two bespoke triple-glazed Ruhm Flushlight roof windows. Centre pane U-value:0.8. Two Fakro U6 roof windows with Thermo flashing system. Overall U-value: 0.81

Heating system

Before: standard efficiency gas boiler and radiator system.After: 30kW 93% efficient Worcester Bosch Greenstar modulating condensing gas boiler with HeatmiserPRT-TS / PRT-NTS controls & radiators. Two 6.97 kW 81% efficient Gazco Studio 2 balanced flue– room sealed – gas fires.

Domestic hot water: 5 sq m Kingspan HP400 solar panels & 200L storage cylinder

Ventilation

Before: some wall vents. After: Passive House Institute certified Dantherm HCH5 heat recovery units, with summer bypass,77% efficiency (including air duct losses)

Lighting: predominantly LEDs and fluorescent lamps, including dimmable LED wall lights.

Water: Kingspan Water ENV100 Envireau Gravity System with 3000L storage capacity for flushingtoilets and irrigating gardens

Green materials: cellulose insulation, GGBS

(from top down) The original house; which endedup having to be virtually demolished; EPS was usedto externally insulate the walls; the ductwork for theMVHR system inside the airtight layer; a thermalimaging test at 5C external temperature

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We began house hunting late in 2009 as acouple with two small children and an interestin ecology and green building. We were look-ing for a bigger home which had the potentialto be made more eco-friendly.

Having moved in May 2010 into a house whichneeded quite a bit of work doing, but which hadthe perfect location for us and a generous garden,we took a year to plan and decide that goingall-out and doing a complete retrofit to the Enerphitstandard would be the best long-term strategyin ecological, financial and comfort terms.

With our aims firmly in mind, in the summer of2011 we approached ReDesign, a local architect

with an interest in energy efficient and eco-friendlybuilding practice, though no prior experienceof passive house work. They helped us greatlyto refine and finalise the general design andsuggested Burton Building Solutions as themain builder – again, a business with an interestin learning more about energy efficient buildingbut no passive house experience. We workedclosely with the builders from the earliest designstages to ensure that as many as possible ofthe more complex elements of the design, fromairtight layer continuity to elimination of cold bridges,could be dealt with before starting on site.

We borrowed the basic design for the retrofitfrom the fantastically detailed information Andy

Simmonds [CEO of the AECB and partner inSimmonds Mills Architects] has provided forhis Grove Cottage project, then used theAECB’s details to refine certain elements.This allowed us to get reasonably close to En-erphit standards with the first iteration of thedesign, saving costs and allowing us to con-centrate fully on the very unfamiliar demandsof passive house retrofit.

As a team composed entirely of novices, weapproached Alan Budden from EcodesignConsultants to help us determine the feasibil-ity of our ideas and to ensure that our end re-sult would be able to be certified as Enerphit(provided we installed everything correctly).

Derbyshire upgrade blitzesEnerphit targetHitting the Enerphit standard can be challenging for even the most seasoned passive house specialist, sowhat chances did Kate and Geoff Ball’s semi-d have when the architect and builder had no passiveexperience? With a well-planned approach and no end of enthusiasm, they passed with flying colours,as Kate Ball explains.

Between all of us, the design was tweaked re-peatedly, and then tweaked again when JohnTrinick from Warm did the certification PHPPmodelling before we started the build.

For airtightness, Paul Jennings from Aldaslooked over our protocol before the build andprovided a day of training in the early buildstages for all of the main people involved inthe project. We believe this was instrumentalin allowing us to achieve a good airtightnessresult, since afterwards everyone fully understoodwhat would be involved in sealing the house.

Given that the house was habitable and large,if rather leaky, we decided to live in the housethroughout the retrofit. We knew that with youngchildren, living in the house during the build wouldn’tbe the easiest option, but we decided that thebenefits of being on site throughout the proj-ect would far outweigh the discomfort (exceptfor the bit where the floors were dug out – wecamped out with family for two weeks!). This

did result in a lot of moving of furniture (mostlyinto a storage unit) and lots of washing up inthe bathroom basin, but was in the main goodfun – though it would have been nicer in aless rainy year.

During the build, we encountered a variety ofissues – from the asbestos tiles we foundunder finger parquet, which was itself under acarpet we removed the week before buildingstarted, to the discovery of a missing dampproof course in the original house walls, to therepeated flooding of the trench during below-DPC external wall insulation installation. Thislast issue led to the insulation floating off thewalls repeatedly, until the main builder – ratherthan the specialist sub-contractor – suggested apump to keep the trench empty. The pumphad no level cut-out, so needed exhaustinglyregular checking day and night to preventburnout until the trench was backfilled.

The greatest worry we had during the buildwas about the airtight layer. Even with rathererratic external wall insulation contractors, itwas a simple enough job to supervise and en-sure that the brick parge coat was installedcontinuously. But we had read repeatedlyabout the dangers of weather exposure forairtight products, and the need to keep every-thing dry – and this in the wettest summer onrecord. Many hours were spent re-tapingslightly wind-torn staple holes in the pitchedroof Intello layers, and even slashing holesinto the flat roof Intello to permit the lakes ofwater which had gone through the tarpaulinsand the as-yet-unsealed OSB to flow into theutility room and allow the roof to dry out. Westuck to the rule of only putting airtight tapesonto completely dry substrates, and remark-ably this seemed to work. The tapes didn’t moveat all, even in areas where the sequencing ofexternal wall insulation with flat roof insulationmeant that various sections of tape spent afair while wet. Our final air test result of 0.32ACH, with the only noticeable leakage arounddoor locks and corners, would seem to indi-cate that our policy of doubling up all the air-tight layers on the timber framed sections wasa good idea, particularly since some of theOSB did get very wet, which may well haveaffected its airtightness.

The UK’s favourable feed-in tariff meant itwas financially (if not necessarily totally eco-logically) viable to install solar panels. The3.96kWp up-cycled panels from Innotechwere installed by Ethical Solar. We were de-lighted to find a company upgrading secondsquality solar panels for more long-term usethan solar powered toys. Meeting the deadlinefor the Autumn 2012 feed-in tariff reductionwas difficult due to weather and sub-contrac-tor related delays, and led to a strange con-struction sequence in which the south roof ofthe extension was fully sealed, insulated andtiled while the north roof still had only the I-beams in place. Due to the positioning of thehouse, the panels are pleasingly un-ostenta-tious – people who visit assume the housedoes not have them, which lets us lecturethem on all the insulation and convince themthat the house really is eco-friendly beforesolar panels are even considered!

One regret would be that as a novice team,we had so much to concentrate on that we didnot manage to use the most environmentallyfriendly insulants, where contractors were de-termined to use more familiar products. This

has led to the use of PIR in the project underfloors and on the flat roof, when we wouldhave preferred to use the same EPS as theexternal walls, if only to make recycling thehouse many years in the future simpler. Ide-ally, timber waste-based insulation would beour insulant of choice given unlimited spaceand finances.

Another slight issue – though this one was re-solvable – was that the very large roof ridgebeams provide our most noticeable thermalbridge. With our warm roof construction, thisweirdly meant that snow melted from the ridgeof our roof sooner than from the roofs of insulated(and I suspect under-heated) cold roof houseson the road. We intend to rectify this by in-stalling 400mm mineral wool insulation underthe ridge beam in the attics, to make the con-ductivity of the ridge area approximatelyequal to the conductivity of the rest of the roof.

Probably our favourite part of the project nowis the MVHR – which is a surprise since wedidn’t expect it to work anywhere near as wellas it has. It dried out the house beautifullywhen it was first turned on in the winter, mak-ing decorating rooms far faster than it wouldhave been, and solving all the unpleasantdamp issues which occur with a family-worthof laundry in a normal house in cold weather.In the summer, the filters are doing their workvery nicely: Much as we love having openwindows and hearing the birdsong, closedwindows and a very low internal pollen countare helping the hayfever sufferers in thehousehold no end.

The question of occupancy in a large house wassomething we were concerned about, havingrealised early on that while a small house withhigh occupancy will look worse on PHPP thana large house with low occupancy (since thatworks on floor area, not number of people), inreal terms the energy used per person may wellbe lower in a smaller, less energy efficient housethan in a larger, more energy efficient house.The first floor two-bedroom extension and util-ity extension left us as a family of four usingtwo bedrooms of a five bed house. We havebeen lucky to find two additional housematesto bring our occupancy up to six, which seems abit more reasonable for the space we have –and has the added advantage of helping to payoff the mortgage. Adding in a small child mindingbusiness and voluntary home educating groupsall run from the house, the occupancy looks �

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really quite good.

The calculated space heating demand comesin at 23.1kWh/m2/yr. Entertainingly, if you changeour house from normal residential to student/oldpeoples' home, the figure drops to about 13kWh/m2/yr. We're hoping we'll perform nearthis figure. We do actually have two studentsliving in the house, and I work from home, runvoluntary groups here and home educate ourkids, so our occupancy is very high.

Part of our hope in undertaking this retrofitwas to provide ideas for other people lookingto improve the energy efficiency of their ownhomes. To this end, we joined the Superhomesnetwork and are holding various tutorial ses-sions and open days throughout the year tohelp make simple energy efficiency measuresmore accessible to local people.

SELECTED PROJECT DETAILSClient: Geoff and Kate BallArchitect: Nigel Turner, ReDesignPassive house Enerphit consultant:Ecodesign ConsultantsStructural engineer: David Bayliss ConsultingMain builders: Burton Building SolutionsAirtightness trainer & tester: Paul Jennings, AldasExternal wall insulation: PermarockWindows & doors: Green Building Store/DreweximAirtightness tapes, membranes & grommets: Ecological Building SystemsMVHR system: Paul Novus 300 Ventilation ductwork: LindabFlat roof waterproofing: SarnafilSolar PV: Ethical Solar






PROJECT OVERVIEW:

Building type: 1950s east-west facing brick built two-storey detached house

Location: urban site, Derby

Budget: approx. £170k

Certification: Enerphit certified

Space heating demand

Before: 153 kWh/m2/yrAfter: 23 kWh/m2/yr

Heat load

Before: unknownAfter: 11 W/m2

Primary energy demand (PHPP)

Before: 403: kWh/m2/yrAfter: 115 kWh/m2/yr

Energy performance certificate (EPC)

Before:The pre upgrade EPC stated the house had full loft insulation, full double glazing, full cavity wall insulation,full thermostatic control on the heating etc, none of which was accurate, rendering the EPC worthless.After: Unknown

Energy bills

Before: £128 per month on gas and £37 per month electricity in 2011-12 (house occupancy 4)After: £26 per month on gas and £30 per month electricity in 2013 (house occupancy 6)

Airtightness (at 50 Pascals) Before: >10 ACHAfter: 0.32 ACH

Ground floor: original floor dug up, adding 180mm PIR insulation with 100mm PIR down-stands tofootings and 30mm phenolic up-stands to prevent slab contact with wall to reduce thermal bridging.Total floor U-value: 0.119

Walls

Before: (variously) unfilled cavity wall, solid brick wall, and mineral wool filled brick-brick cavity wallor brick-block cavity wall.After: Permarock external insulation system including 250mm graphite EPS in two cross-bondedlayers, airtight cementitious parge coat, external layer of brick, cavities all filled with mineral woolwhere cavity exists (cavity between 0 and 80mm on different walls), internal layer brick or block,again different construction on different walls. U-Value 0.102

Extension walls: timber frame walls – 250mm graphite EPS in two cross-bonded layers, airtight layersof taped 18mm OSB then taped Intello membrane; 100x50mm studs filled with mineral wool, thenplasterboard. U-Value 0.100

Existing roof

Before: uninsulated slate roof with some mineral wool laid flat between ceiling binders but with manygaps in the insulation.After: slates, battens, breather membrane, 18mm OSB, 400mm mineral wool between I-beams,taped Intello airtight layer then taped OSB airtight layer, pre-existing 3x2in rafters. U-Value 0.118

Extension roof: pitched roof as existing roof without 3x2 rafters. Flat roof has 70mm growingmedium and mixed vegetation, water retentive and protective layers, Sarnafil waterproofing, 180mmPIR insulation in two cross-bonded layers, airtight layers of taped OSB then taped Intello membrane, roofjoists filled with leftover graphite EPS then plasterboard. U-Value 0.085

Windows & doors

Before: rotten timber-framed single & double glazingNew triple-glazed windows: Green Building Store EcoPassiv Passive house suitable triple glazingwith timber frames. U-Value 0.87-0.97

Heating system

Before: >25 year old gas boiler & 15 radiators After: new gas fired Veissmann A rated combi using approximately three of the remaining seven radiatorsduring last winter.

Ventilation

Before: no ventilation system. Reliant on infiltration, chimney and opening of windows for air changes.After: passive house certified Paul Novus whole house mechanical ventilation systems with heat recovery,over 90% efficient, connected to Lindab steel ducting.

Green materials: re-use of existing carpets etc. where possible, FSC certified timber throughoutbuild, use of reclaimed parquet through ground floor.

Electricity: 3.96kWp solar PV system

upgrade

(below, l-r) Front facade with airtight parge completed; the front windows in place; extension wall onto utility roof showing cavity closure through joists; thehouse features a green roof with mixed vegetation; the rear of the house showing the timber frame extension;(p71) (bottom right, clockwise from top left) externalwall insulation showing door overlapped by first layer and second layer being installed; faults in the insulation like this were foamed before the mesh coat wasapplied; two layers of insulation installed across frontage; insulation blocks being inserted into roof to ensure continuity as second layer insulation is installed

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This year’s sell-out UK Passivhaus Confer-ence, held in October 2013, took as its theme‘Passive House at Scale” – and there waspalpable excitement about how many largeschemes were coming through.

The opening talk was on the 53-apartmentmixed-use Chester Balmore development builtfor Camden Council by Willmott Dixon (with de-sign input from Rick Mather Architects and Archi-type), now nearing completion. Also featuredwas Sustainable by Design’s Enerphit refur-bishment at Gallions Housing Association’sParkview Hub – a five-storey concrete slabblock containing 18 maisonettes, well under way.

Delegates heard about Architype’s proposed150-home ‘Archihaus’ development in Here-fordshire, which now has planning permission,and hints of another 100+ home speculativedevelopment to go ahead using the Beattie Pas-sive system. Completed schemes includedthe 41-home Lancaster Co-housing scheme,and Parsons and Whittley's two passive housedevelopments (of 12 & 14 units) for HastoeHousing Association – plus the news thatHastoe is building four more schemes.

Elsewhere, many other large passive housedevelopments have been completed or are un-derway or planned in the UK and Ireland, including

a good number of social housing schemes, andseven primary schools so far. While Ireland startedin passive house before the UK and hasgained some significant certified projects –such as a Tesco supermarket in Co Waterfordand UCD student halls, both built in 2008 –larger passive projects have been few and farbetween since the recession. But this may bedue to the unprecedented decline in constructionactivity in Ireland – where virtually no newhousing schemes of any size have gone aheadin recent years, other than one-off self builds– rather than a lack of appetite for passive house.

How does passive house work at a scale larger

Passive houseGOES LARGEPassive house is no longer just the preserve of the self-builder. With over 300 passive houses built todate in multi unit-schemes and a thousand more on the way – along with major non-domestic builds –increasing numbers of British & Irish developers are going passive. But how will the sector cope withupscaling, and will the most cost-conscious developers be attracted to the standard?

Words: Kate de Selincourt

than the one-off private house? There aredefinite advantages. The most obvious, in thecase of bigger single buildings and terraces,is an advantageous surface-to-floor area ratio.

A good form factor means it is simpler to achievethe required energy target – which can trans-late into more modest insulation values, or slightlycheaper windows or other components – orof course, even better performance.

As Peter Ranken of Tooley and Foster Part-nership’s consultancy Accredited PassivhausDesign put it about one larger building type:“As a building shape, care homes are alreadyvery efficient, with a lower ratio of externalwall (heat loss) to floor area compared to de-tached houses. Therefore the step change toachieve passive house performance is smallerthan other building types.”

There can be economies of scale at the designstage too. A repeated detail gets great valueout of the design input – so pouring maximumtime and attention into optimising details in alarger build is well worthwhile. A great detailgenerally costs little or no more to build, butreduces the pressure to specify expensivehigh-performance components elsewhere. Con-struction may also be honed, and speeded up,through repetition.

Economies of scale can make it possible to con-sider passive house or Enerphit level retrofitsthat might otherwise appear uneconomic. (AsJoseph Little told the Asssociation of Ireland’sSee the Light conference in Dublin in October,“Enerphit is not cheap unless delivered in bulk”).

However, there are sometimes complicationswith getting a larger single building to the passivehouse standard. Additional energy-hungry servicesmay have to be included, such as lifts, cateringkitchens or sprinkler systems.

Most significant perhaps is the fact that you can-not always construct a bigger building on aninsulated slab, because it may be too heavy.Sometimes it is necessary to confine insula-tion to a “skirt” round the foundations, thoughon occasion ingenious solutions have beendeployed, such as the Interserve build at RichmondHill Primary School in Leeds where “high-strengthinsulation normally used in industrial processplant installations” was used between the foun-dation piles and the steel frame.

On site

Do big passive house builds face extra challengeson site? One issue mentioned regularly is theneed for good communication, and, ideally, con-tinuity of staff. This can be harder to achieve wherea big, mainstream contractor follows conven-tional practice and subcontracts on price, withfrequent reviews and frequent changes ofpersonnel.

As John Lefever, regional head of developmentat Hastoe Housing Association put it: “Weused major housebuilders for our first passivehouse developments, but this time round wehave gone with local SMEs, because they aremore hands-on. We feel it will be easier to talkmore directly to the people we need to talk to,and they tend to use their own in-house teams– with bigger guys they use subcontractorsand they negotiate for new subcontractors allthe time – they don’t keep the same crews.”

Larger firms can overcome this: at Thomas Vale

Construction for instance, they have main-tained continuity of both in-house staff andsub contractors through several passive housebuilds; Willmott Dixon tackled this at ChesterBalmore by running an induction procedurefor everyone who came on site.

Prefabrication

Several of the latest large passive house buildshave opted for an offsite approach. Construc-tion has just begun on a 51-unit developmentfor Circle Housing in Rainham, on the ThamesEstuary. The four blocks are being built by ClimateEnergy Homes using an offsite constructionsystem. Prefabrication was also used to buildthe 23-home Sampson Close developmentfor Orbit Housing, as is planned with Archihaus,in a factory to be established for the purpose.And prefabrication is also being used to formthe cladding as part of the Enerphit retrofit atthe Parkview Hub.

Alexander Gumpp of Gumpp and Maier, con-structing the cladding panels for Parkview,believes prefabrication has to be the future:“In Europe we are spending too much on theprocess of building. We need to optimise workflows to increase the money going into thebuilding – the bit the customer gets to keep.”

The shortened time on site with prefabricationis a bonus – especially worthwhile in a retro-fit where, as with the Parkview Hub, the job istaking place with occupants still in place.

Cost and client motivation

Despite some economies of scale, for largerpassive house projects it is still common tohear there is a cost premium of something like8% – much the same as with smaller builds.Not everyone thinks this is necessary: Archi-type (for both their schools and their Archi-haus houses); Beattie Passive (houses builtto their system, single or multiple) and ClimateEnergy (with their off-site build system) all saythey can build passive house at or below con-ventional costs.

Nonetheless, the rapidly rising interest fromclients in many sectors suggests that even wherethey do have to pay more, they feel there is agood business case for extra up front investment.

For those who will occupy the building, the fi-nancial case can be clear – extra investmentoften pays back pretty quickly in running costsavings. According to Peter Ranken, “the firstpassive house care home in Britain is reportedto have cost 6% more, and the anticipatedcost savings will pay this back in eight years.”

Interserve Construction, who have built their own600 sq m offices in Leicester and two passivehouse schools, have carried out calculationssuggesting payback for passive house couldbe even faster. And as business developmentmanager John Walkerdine points out, “whenyou look beyond that, with a life expectancy of50 years or more you can see how the sav-ings add up in the longer term.”

Whole-life costing is becoming more common,so these considerations could increasinglysway clients towards passive house. How-ever, there are still old barriers to break down,Walkerdine suggests: “There is traditionally aseparation between facilities managementbudgets and capital budgets, especially in thepublic sector. Facilities management is not goingto give estates a chunk of their budget to �

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(opposite, clockwise from top left) OakmeadowPrimary School; Sulgrave Gardens; DormontEstate; Chester Balmore; Kingstone; (this page,top down) CREST Pavilion; Lancaster Cohousing;Hadlow rural regeneration centre; Mildmay Centre;UEA Enterprise Centre

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enhance the building, even though it wouldcut running costs. Those budgets are a per-sonal thing!”

“However, now that public spending is sosqueezed, people have to start putting the twotogether – and we are seeing this starting to hap-pen, in the NHS for example.”

There could be less direct – but still highly fi-nancially worthwhile – benefits. Interservecompared sickness absences in the last yearat their previous offices, with the first year atthe new ones, and found a 13% decrease insick leave. “An improvement like that is wortha lot of money to us,” Walkerdine pointed out.While this is of course a single result, it echoesanecdotal reports from occupants of residen-tial passive houses.

There are other good reasons to commissionto passive house that also translate into agood business case, including for landlords whowill not be paying the bills themselves. For so-cial landlords, helping protect residents fromfuel poverty is always an important part of theircorporate mission; this motivation has led tothe growing movement by social landlords inthe UK to look beyond the statutory standards,and build and refurbish to passive house.

But it also makes financial sense. Accordingto John Lefever of Hastoe “our first two pas-sive house developments have been occu-pied for one and two years respectively, andto date we have had zero arrears.” This is de-spite Hastoe having been obliged by the funder,the Homes & Communities Agency, to chargehigher rents (this was Hastoe’s motivation forgoing to passive house: they wanted to keepoverall costs down for tenants). “Heating billsare only about £120 a year,” says Lefever, “soalthough rents are higher, overall, our tenantsare better off.”

Neighbouring Broadland Housing Group areplanning a 250-unit passive house apartmentdevelopment, and chief executive Michael Neweybelieves social landlords should be allowed tocharge higher rents to help finance more energyefficient homes – and if Hastoe’s experienceis repeated, everyone could be better off that way.

Perhaps unsurprisingly, in the commercialsector most interest to date “has come fromPLCs who will be occupying their own building,”says John Walkerdine. Might commercial land-lords ever follow suit? They might, if the ben-efit from lower running costs here can also be

shared with landlords via higher rents.

Interserve moved from “grim” former barracksbuildings whose running costs were higherthan the rent, into the passive house offices thatthey commissioned and constructed on a businesspark. The building was paid for, and is ownedby, the park’s developer, Raynsway properties.“We told the developer we would be able topay a higher rent, because our running costswould be so much lower – we are now payingout less overall, even though we are now in abeautiful new building with higher rent.

“The property agent for our developer has reallytaken on board the advantages of our building,they realise it’s the way to do it. It’s about findinga way to sell that value, and get a good return tothe developer while still benefitting the occupier.”

Are valuations getting in the way?

Despite some powerful financial arguments,a client who wants to build to passive houseat scale may still need to justify the expensein relation to the external valuation – and cur-rently, these tend to be no higher than for aconventional building. This may be at least inpart because passive house has barely beentested on the open market. Where it has(mainly with residential units), the buildingshave sold well – though not necessarily at a pricepremium.

In London, some of the first passive homesavailable for private buyers have been inmixed developments built by social landlords(the profit from the private sales goes towardsbuilding the low energy affordable housing).Octavia Living, part of Octavia Housing, hasbuilt 29 passive homes in West London, ofwhich eight were for sale on the open market.These houses have all been sold and occupied,reports Sue Dance, Octavia’s head of salesand marketing: “For some buyers, the passivehouse features were the first attraction; forothers it was the location, the finish, and the factthey have parking spaces! It was about 50:50.

“For the ones who were initially interested be-cause of passive house, the low bills weredefinitely an attraction, and one family specif-ically wanted the filtered air, for health rea-sons. For the others, as they found out moreabout what the passive house features meant,I think this ‘closed the sale’. And I can definitelysay it did not put anybody off!”

The reaction in Camden has been similarlypositive, with five of the first 15 Chester Bal-

more apartments already sold, as Passive HousePlus went to press – only a couple of weeksafter they were released, and only with localmarketing. David Jubb of agent Savills wassure that passive house was an ingredient draw-ing people to the homes; not least becausethis was the same fortnight that saw a con-troversial round of energy price rises in the UK.

Despite selling prices being comparable withnon-passive properties, both sets of homes aremaking a profit for the developer (though Lon-don house prices might make this easier herethan elsewhere).

In Lancaster, the 20 members of the co-housinggroup needed to build and sell an additional 20units for £20 - £40,000 more than the local rate forsimilar standard homes in the area, to make theirsite viable as a whole. And this wasn’t a problemin the end, reports the project manager Jon Sear:

“We initially tried with a local estate agent, butthey really didn’t know how to market our houses.Fortunately we were able to sell them all directly,for the price we wanted, through our websiteand by word of mouth. And passive house wasdefinitely a selling point.”

Irish developer Joe McGowan shares this viewand is backing passive house in a speculativedevelopment in North Wales. McGowan re-cently gained planning permission on a 12.5acre site in Abergele, and has started on sitewith a 140-unit passive house scheme that willuse Irish manufacturer MBC Timber Frame’ssystem. “We’ll have show houses up by March,”says McGowan, adding that the scheme willconsist of “conventional homes” released onto the open market, at the lower end of themarket on price. While McGowan – who plansto have the homes passive house certified –agrees that the market may be willing to paya premium for low energy housing, he retainsonly cautious optimism about the broader eco-nomic context. “Apart from London, the re-covery has been slow,” he says.

With the first big open market passive househousing developments now anticipated, alleyes will be on their commercial success. De-spite the apparent reluctance of the UK gov-ernment to follow Ireland’s example and setgood performance standards for building, itmay be that as word spreads, more corporatebodies, more homebuyers, and more tenantsin all sectors will seek the savings passivehouse offers, all the same. It will be interesting tosee if, and how quickly, developers respond. �

(clockwise from left) Moynalty primary school; Tesco store, Tramore; Roebuck Castle; Glen Ashling Nursing Home; (p79, clockwise from to left) Ditchingham; SampsonClose; Racecourse; Wimbish

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Passive progressIn a far from exhaustive list, we’ve compiled this list of Irish &

UK passive projects including multi-unit housing schemes

and non-domestic buildings, but excluding one and two unit

housing developments. Taking UK housing alone, our count

includes over 300 units built and another 1000 planned or mid

construction.

Residential – social housing

Completed

Tigh-Na-Cladach, Dunoon: 14 houses

Knight’s Place: 18 apartments for Exeter City Council by Gale & Snowden

Racecourse, Houghton-le-Spring for Gentoo Housing: 25 bungalows designed byMark Siddall

Bryce Lodge, Horsham: 12 houses on a development of 38, built by Osborne forSaxon Weald, designed by MH architects.

14 houses in Ditchingham, Norfolk & 12 houses at Wimbish, Essex by Hastoe &Parsons & Whittley Architects.

Dungannon, Northern Ireland: Five houses for Oaklee Homes Group, designedby Kennedy Fitzgerald Architects.

4 homes at Fulmodeston, Norfolk, by MOLE Architects for Broadland Housing Association.

Sampson Close, Coventry: 18 apartments & 5 houses, designed by Baily Garnerfor Orbit Homes.

4 houses for Fife Housing Association using Beattie Passive system.

Planned/on site

Hastoe has 100 units planned, including 14 homes at Hatfield Heath, Essex; 3rental units at Horseheath, Cambridgeshire; 15 homes at Outwell, Norfolk; & 6units at Burnham Overy Staithe, Norfolk

Private Housing

Completed

Dormont Estate, Lockerbie: Eight private rented houses designed by White HillDesign Studio.

Planned/on site

Grange Lough, Rosslare, Co Wexford: 8 units – 1 built so far, by Michael Bennett & Sons.

Cambridge K1 Co-housing community: plans for 36 homes.

Beattie Passive system licenced to a developer on a 100+ unit scheme in Sheffield,& have created Beattie Passive Norse, a joint venture with a commercial offshootof Norfolk County Council offering low cost passive houses, including social (suchas 12 houses with Great Yarmouth Borough Council and are currently in discussionto deliver a substantial social housing scheme in Nottingham).

250 apartments, Norwich, planned by Broadland Housing Association.

140-unit development in Abergele, north Wales by Joe McGowan.

Mixed use

Completed

Sulgrave Gardens, London: 30 units, by Cartwright Pickard architects for Octavia Housing.

41 unit Lancaster Cohousing development, Lancashire, built by Whittle Construction,designed by Eco Arc.

Planned/on site

Kingstone, Hereford: 150 units by Archihaus.

Chester Balmore, London: 53 units. Built by Willmott Dixon, designed by RickMather Architects for Camden Council.

51 units at Rainham, Essex by Circle Housing Group & Climate Energy Homes.

4 units, Islington, London, including 3 Enerphits and one passive new build. Designed by BereArchitects, with potential for larger scale roll out across Islington Council's existing stock.

Student accommodation

Completed

Roebuck Castle,Dublin: 130 student rooms, 3,000 sq m. Designed by KavanaghTuite Architects.

Residential care

23-bedroom extension to Glenashling nursing home, Co Kildare, built by MDYConstruction.

Planned/on site

93 units for a UK housing association by Accredited Passivhaus Design.

Domestic retrofit

Planned/on site

Manchester: 32 unit Enerphit for Eastland Homes, design by 2e.

Portsmouth: 107 unit Enerphit for Portsmouth City Council, designed by ECD Architects.

Parkview Hub, London: 18 unit Enerphit for Gallions Housing Association by SustainableBy Design.

Offices

Completed

Canolfan Hygdden office and training centre in Machynlleth by JPW.

500 sq m Viking House in Dover built by WCR Property.

Retail

Completed

4000 sq m Tesco supermarket in Tramore, Co Waterford.

Planned/on site

Pharmacy & single apartment in Clonmel, Co Tipperary by Paul McNally Architect

Primary schools

Completed

Montgomery School, Exeter: designed by NPS South West, built by BAM; Oak-meadow & Bushbury Hill primary schools, Wolverhampton, designed by Architype& built by Thomas Vale); Leeds City Council’s Architype-designed SwillingtonSchool and Space Architecture-designed Richmond Hill school, both constructedby Interserve.

Department of Education primary schools in Powerscourt, Co Wicklow andMoynalty, Co Meath, completed in 2012.

Planned/on site

Wilkinson primary school, Wolverhampton designed by Architype & built by Thomas Vale.

Tertiary and continuing education

Completed

Hadlow rural regeneration centre, designed by James Anwyl, built by Eurobuild.

Planned/on site

CREST Pavilion at South West College, Enniskillen: Designed by Paul McAlisterArchitects.

UEA Enterprise Centre, Norwich: Designed by Architype, built by Morgan Sindall.

Community & other non-domestic buildings

Completed

The Simmonds Mills designed Centre for Disability Studies, Essex & Green Basefor Helena Housing, St Helens, Merseyside.

Mildmay Centre passive house retrofit, Islington, by Bere: Architects

Planned/on site

County archive building in Hereford, built by Kier Construction, designed by Architype.

1114 sq m church in Sheffield for Christ Church Central, designed by Architype.

Savoy Pier, a floating passive house building for Woods River Cruises, London, byBere: Architects.

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glos

sary

Air-to-water heat pumps use outside air as a heat sourceand delivers it to internal spaces via hot water (eg underfloorheating pipes) using electricity to boost the temperature.

Airtightness/pressure/blower door test This is usedto work out a building's airtightness. A fan mounted to anexternal door or window is used to pressurise or depressurisethe interior of the building, forcing air in or out through anygaps or cracks. The building's airtightness is determined bymeasuring the force needed to maintain a certain pressuredifference (typically 50 pascals) between the inside andoutside of the building.

Damp proof course A horizontal barrier in a wall thatprevents moisture from rising. For a solid floor, the dampproof membrane provides the same function.

Enerphit This is the Passive House Institute’s less oner-ous standard for retrofit projects. It demands airtightness of1.0 air changes per hour (ACH) at 50 Pascals and spaceheating demand of 25kWh/m2/yr (as opposed to 0.6 ACHand 15kWh/m2/yr for certified passive house new builds).

EPS Expanded polystyrene, a type of plastic foam often usedfor rigid thermal insulation. It derives its insulating abilityfrom air trapped within its closed cell structure.

Exhaust air heat pump This type of heat pump extractsheat from waste air leaving a building and uses it to providehot water or space heating, using electricity to boost thetemperature if needed.

Feed in tariff This is a fixed price per kWh that a government,one of its agencies or an energy supplier may pay pro-ducers of renewable energy for export of that energy to theelectrical grid.

Hollow block This is a type of concrete block with two largecavities, each typically nine inches long. Commonly usedfor single-leaf construction in the greater Dublin area untilmodern times, some people attempt to retrospectively insulatehollow block walls by injecting insulation into the block work– a measure that should be avoided, due to the impossibilityof ensuring continuous insulation. Not to be confused withcavity wall construction.

Internal heat gains means “free” heat is produced fromwithin a building, such as by building occupants, lighting,cooking, or electronic equipment.

MVHR A technology that ventilates a building while alsorecovering heat from extracted air. MVHR systems typicallyextract warm, damp air from ‘wet’ rooms like kitchens andbathrooms and use it to heat cool, fresh incoming air, whichis then usually piped to living spaces such as living roomsand bedrooms.

OSB Oriented strand board is an engineered wood labelproduct made from altered flakes or strands of wood orientedin specific directions. It is available in a variety of thicknesses,and when its joints are taped and sealed it is sometimesused as the airtight layer on timber frame projects. Thoughthis approach is taken on many passive house projects, itsometimes struggles to meet the highest levels of airtightnessbecause the variable nature of the material leads to variableleakage rates.

Passive stack ventilation utilises temperature difference

to ventilate a building. Because warm air is less dense thancold air, it will rise and subsequently leave the building ifextractor vents are strategically placed. This will create a“chimney” effect that will draw in cooler air from intake ventsbelow. Passive stack ventilation relies on the temperatureinside being warmer than outside.

PHPP Passive House Planning Package, the spread-sheet-based software used to design and certify passivehouse projects. Available from the Passive House Institute.

PIR Polyisocyanurate, a type of plastic foam that is oftenused as rigid thermal insulation. It is one of the best per-forming (ie least thermally conductive) common insulationmaterials on the market. It derives its insulating ability fromgases trapped in its closed cell structure.

Solar gain This refers to the heat energy that a buildingreceives passively from the sun, normally through its glazing.Designing a building so that most of the glazing faces south,with little glazing facing north, is one of the basic principlesof passive house design in the northern hemisphere. Thishelps to reduce the need for mechanical heating systems.

Solar thermal This is heat energy generated by the sun,usually via solar collectors such as flat-plate panels or vacuumtubes.

Steady state heat loss assumes that temperatures outsideand inside a building remain constant for a sufficient amountof time, so the calculated heat loss is steady. In reality tem-peratures change constantly, so this is a simplification, butcalculating the steady state heat loss during peak heatingconditions is often used to size heating equipment.

Structural insulated panels consist of a panel in whichinsulation – typically plastic foam – is securely sandwichedbetween two structural boards (typically OSB, but alsosheet metal, plywood, cement fibre and other materials).

Thermal break A building element of low thermal con-ductivity (ie good insulating ability) that is used to preventthe loss of heat at a specific point in the building envelope.

Thermal mass The capacity of a building material tostore heat. Materials with a high thermal mass absorbheat, store it and then release it later on. This can help tosmooth out extremes in temperature inside a building,helping to maintain a comfortable internal environment andreduce the need for heating. Heavyweight constructionmaterials like concrete and bricks have more thermal massthan lightweight materials like timber.

Thermal conductivity This is the ability of a material totransfer heat by conduction, one of the three main waysthat heat moves (along with convection and radiation).

U-value The U-value of a material is the rate of heat lossthrough that material. The lower the U-value of a material,the less heat can pass through it and the better it is at insulating.U-values are measured in watts per metre squared kelvin (W/m2K).

Vapour check/vapour control layer A material that isdesigned to significantly reduce the transfer of water vapourthrough a building element (e.g. wall or roof). They areoften installed on the warm side of a construction to pre-vent water vapour from reaching the colder elements andcondensing.

Perplexed by all this talk of U-values, blower door tests and embodiedenergy? This latest instalment of our sustainable building glossary willhelp you get to grips with the key terminology. These entries will beadded to an online glossary at www.passive.ie/glossary, which willcontinue to grow in detail as each new issue comes out.

passive house plus issue 5 (irish edition)

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