passive house plus issue 4 (uk edition)

editor’s letterhe self-deprecatingly titled sustainability website Treehugger.com is one of thegreen giants of the internet. Previously rated the top sustainability blog by NeilsenNetratings and included in Time Magazine's top twenty-five blogs, Treehugger attractsmasses of readers interested in green living – and green design in particular –from around the world. So it was a great day in the Passive House Plus offices when

Treehugger’s managing editor Lloyd Alter chanced upon our magazine, and felt sufficientlyenthused to write about us.

“What a joy it was [�] to discover a new magazine from Ireland, with a UK edition, that is just fullof more great green designs of passive houses, multifamily projects, schools office buildingsand even boathouses than you could imagine actually existed,” wrote Alter, in a blog post aboutPassive House Plus that made us blush. “I will be dining on this in the pages of TreeHugger forweeks to come.”

If that didn’t make us happy enough, the fact that we’re starting to see a genuine upturn in thenumber of innovative Irish sustainable building projects our readers are planning gives us realcause for celebration. As you may know, we’ve been running an enquiry system since long beforeConstruct Ireland evolved into Passive House Plus. Although the primary function of this systemis to connect readers planning sustainable build and upgrade projects with the advertiserswho meet their needs, it also provides telling glimpses of market sentiment. For instance, justover a fifth of the nearly 300 enquiry forms we’ve received to date relating to the last UK editionof Passive House Plus included estimated project budgets. Their combined total was nothingshort of astonishing: £320m, including £38m worth of projects aiming for certified passivehouse. Interestingly, 37 of the enquiries were relating to multi unit housing schemes, including sixprojects aiming for certified passive levels, and a further seven aiming to go “near passive”.

It’s tremendously heartening that projects of this nature are beginning to happen – and thatarchitects, contractors and clients are looking for help from a magazine about ultra low energybuilding. They may also find inspiration in the broad range of exemplary projects in this issue,including technical case studies on the three award-winning projects at the recent UK PassivhausAwards and on three of the best recent Irish passive and near passive projects, as well as thearchitecturally stunning certified passive homes, museum and skyscraper in our internationalbuildings feature.

We launched Passive House Plus into the UK because of a large and growing demand fromBritish designers, contractors and clients for robust, independent information on building approachesthat achieve genuinely low energy results. While it’s clear that this demand is growing in spiteof underwhelmingly lax energy efficiency standards under building regulations, and while thismagazine and the industry forming around passive house can undoubtedly survive and eventhrive as a growing niche, our ambitions must be greater. Quite simply, the current minimumstandards – and the proposed changes as the UK crawls towards a spurious zero carbon target –are not fit for purpose.

Regards,the editor

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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 certificate pending

Issue 4

PUBLISHERS: Temple Media Ltd.PO Box 9688, Blackrock, Co. Dublin, Ireland

T: +353 (0)1 2107513 / +353 (0)1 2107512Email: [email protected]

EDITORIAL

EDITOR: Jeff ColleyE: [email protected]

DEPUTY EDITOR:Lenny AntonelliE: [email protected]

REPORTER:John HearneE: [email protected]

CONTRIBUTORSTomás O’Leary, Passive House Academy

Andrew Warren, ACEJoseph Curtin, IIEA

Stephen Quinn, Herz & Lang

SALES

Stephen MolyneuxE: [email protected]

READER RESPONSE/ IT

Dudley ColleyE: [email protected]

ACCOUNTS

Oisin HartE: [email protected]

ART DIRECTOR

Lauren ColleyE: [email protected]

PRINTING: GPS Colour Graphics, T: 028 9070 2020

www.gpscolour.co.uk

Publisher’s circulation statement: Passive HousePlus (UK edition) has a print run of 11,000 copies.10,000 copies are posted to architects, clients, con-tractors & engineers. This includes the membersof the Passivhaus Trust, the AECB & the GreenRegister of Construction Professionals, as well asthousands of key specifiers involved in current &forthcoming sustainable building projects

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

Photograph: Uncertified Enerphit houseCo Cork

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6 NEWS

18 BUILDING OR UPGRADING?

Passive House Plus is here to help make your building more sustainable

20 COMMENT

24 INTERNATIONAL

Virtually any building, anywhere can achieve certified passive house status, asthese four transatlantic buildings show – including a Viennese skyscraper, anupgrade to an NYC home predating the Empire State Building, a German museumhousing valuable works of art and a net zero energy home in New Mexico.

34 NEW BUILD

34 Lancashire housing scheme banks on passive

The winner of the Social/Group Housing award at the 2013 UKPassivhaus Awards, Lancaster Cohousing’s Forgebank developmentin Lancashire is riddled with green features. Not only are all ofits 41 homes passive house certified – it scores top marks inthe UK’s Code for Sustainable Homes too.

40 Pioneering passive office surpasses expectations

When it comes to actual energy usage, modern buildings rarelyperform as well as expected. As discussion continues about howto solve the performance gap, one pioneering Welsh passivebuilding has a different kind of performance gap – it’s using 40%less energy than anticipated.

46 Vernacular passive

A building doesn’t have to be designed as a cube to meet thepassive house standard, but it helps. This as yet uncertified passivehouse in Carlow shows that, climate permitting, less compactdesigns can be made passive – by pushing the envelope.

52 Media HQ shows ultra low energy vision

While Ireland’s minimum energy performance regulations fordwellings have come on leaps and bounds in recent years,standards for non-domestic buildings have remained untouched.Which makes forward-thinking media production company TVM’snew ultra low energy HQ all the more impressive.

58 UPGRADE

58 1970s Devon home becomes certified passive B&B

If you’ve ever wondered what it’s like to live in a passive house,a B&B in Devon could be just the ticket. The winner of the privatehousing award at the 2013 UK Passivhaus Awards, this upgraded1970s home proves that even existing buildings can be made passive.

64 Cork home hits 94% heat reduction with Enerphit

The vast majority of energy upgrade projects aim for low hangingfruit measures, and risk locking buildings and their occupantsinto needlessly high energy usage, environmental impact anddiscomfort. This recent home upgrade on the outskirts of CorkCity shows what truly deep retrofit looks like.

70 INSIGHT

Unlocking investment in home retrofit - Lessons from the UK & Ireland

In spite of a consensus that most buildings need deep energy upgrades,both Ireland and the UK have barely scratched the surface. Joseph Curtin

– one of Ireland’s leading energy policy wonks – discusses how to kickstart en masse upgrade work.

73 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 4

News

The Department for Communities and LocalGovernment is set to introduce less ambitiouscarbon reductions for new buildings than it hadpreviously indicated, under planned changesto Part L of the building regulations for Eng-land and Wales set to be introduced nextyear. The department has also launched apublic consultation – titled Next steps to zerocarbon homes: Allowable Solutions – whichproposes carbon offsetting as a means tohelp achieve a notionally zero carbon rating.

In a written statement to parliament on 30 July,communities minister Baroness Hanham an-nounced plans to introduce carbon reductionsof 6% for new homes and 9% for new non do-mestic buildings.

“These Part L changes take an important andtechnically meaningful step towards zero car-bon homes,” said Hanham, “but one that alsoallows government to meet its commitmentsto reduce the overall regulatory burden uponhome builders.”

RIBA’s head of external affairs Anna Scott-Marshall expressed the institute’s disappointmentat the proposed changes. “The government’s

response will provide much needed clarity to theUK construction industry which we welcome,”she said. “These new measures however, arefar less ambitious than previously proposed.We will only be a third of the way along theimprovement needed for zero carbon homesby 2016. Our collective attempts to achieveaffordable zero carbon homes with low energycosts for consumers will suffer greatly becausehouse builders haven’t been encouraged enoughby government.”

The current version of Part L came into forcein 2010, and set 25% carbon reductions fornew homes compared to 2006 standards asdetermined using the Standard AssessmentProcedure (Sap) software. In addition to thestated carbon target for the building, Part Lsets minimum compliance backstops – targetswhich the building must achieve or exceed –for several aspects of the building.

Although backstop U-values improved in 2010– walls, roofs, floors and windows respectivelyimproved from 0.35, 0.25, 0.25 and 2.2 in 2006 to0.30, 0.20, 0.25 and 2.0 in 2010, the backstop forairtightness remained unchanged at 10 m3/hr/m2

at 50 Pa. This compares unfavourably to the

backstops in the Irish version of Part L, whichincludes 60% energy and carbon reductionsand mandatory use of renewable energy sys-tems, as well as backstops of 0.21 for walls,0.16 for roofs, 0.21 for floors – rising to 0.15where underfloor heating is installed – and 1.6for windows, doors and roof lights with an air-tightness requirement of 7 m3/hr/m2 at 50 Pa.But Ireland’s backstop U-value for windows,doors and rooflights assumes their combinedarea represents no more than 25% of floor area,and sets more onerous targets for more ex-tensively glazed buildings – such as a U-valueof 0.8 where their combined area is 58.9% offloor area.

Although Baroness Hanham’s statement didn’tdiscuss U-values or other envelope backstops,it indicated that fabric requirements will betightened. “The emphasis of these changesis on getting the building fabric right and thisis reinforced through the introduction of a newtarget for fabric energy efficiency,” she said.

The consultation on Next steps to zero carbonhomes: Allowable Solutions ends on 15 October.To read the government’s proposal and makea submission visit http://bit.ly/16wvQI6

Government scales back Part L ambitionswith 6% carbon reduction

Passive House Plus adds newonline image galleriesWe're delighted to announce the launch of anexciting new feature for subscribers to themagazine: online image galleries, includingdetailed architectural drawings of buildingsfeatured in the magazine.

From now on, most case study articles in thedigital edition of the magazine will include a linkto an online gallery featuring additional imagesand architectural drawings of the project. Thesewill include detailed diagrams showing insulation,airtightness and thermal bridging details. Abeta version of the gallery feature was introducedin the digital versions of our previous issue,including both UK and Irish editions.

Leading low energy architect Joseph Little said:"The new online gallery feature adds a wholenew functionality to Passive House Plus. I lovethe look of it and will enjoy using it."

This feature is only available for subscribers,including both our standard (print magazine anddigital access) and digital only options. Subscribersto the print edition also receive a free subscriptionto the digital edition giving them access to thefeature. Subscription rates range from €45 foroverseas subscriptions, to £20/€25 for UKsubscriptions, to €10 for digital only subscriptions.

An architectural drawing on our new image gallery feature of a thermal bridge free wall base detail at the Parsons & Whittley-designed Ditchingham passive house scheme, which was profiled in the previous issue of Passive House Plus


News

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Passive House Award open for entry

The 2014 Passive House Award is open forentry. The award, run by the Passive HouseInstitute, aims to illustrate "just how beautifullydesigned extremely energy efficient buildingscan be."

Urban planning projects are eligible for entrythis year alongside individual buildings. Passivehouse or Enerphit certification is required forentry, and projects must also be listed on theInternational Passive House Association’sdatabase at www.passivehouse-database.org

These criteria apply for at least one repre-sentative building in the case of urban planningprojects, which are still eligible for entry evenif they are in the early stages of development.

Judging of the principal award is based solely onarchitectural design. The prize will be judgedby an independent jury, who alongside the mainaward may decide to specially recognise projectsfor their unique attributes, such as innovativedesign, climatic challenges, or unique energyconcepts.

Winners will honoured be at the 2014 InternationalPassive House Conference in Aachen, and in atravelling poster exhibition that will tour worldwide.

The 2014 Passive House Award has been or-ganised by the Passive House Institute withinthe framework of the EU project, PassREg - Pas-sive House Regions with Renewable Energies(www.passreg.eu), under the patronage of the

German Federal Ministry of Transport, Buildingand Urban Development. Prize money will bedetermined by the jury based on the entriesreceived as well as on the special recognitionsawarded and total funding available from sponsors.

The awards were previously held in 2010, as thePassive House Architectural Awards.

Further information and the online submissionform can be found at www.passivehouse-award.org

The deadline for applications is 30 September.

(above) The winner of the 2010 Passive House Award,a multi-family building in Liebefeld, Switzerland byHalle 58 Architects

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This year's UK Passivhaus Conference takesplace on Tuesday, 15 October at Jury's Inn, MiltonKeynes. This year's conference will run over justone day to reduce costs for those attendingand reduce time away from the office. For thefirst time, Passive House Plus will be the con-ference's media partner.

The conference will see "all the features fromlast year and more crammed into just one day",including hands-on training sessions, a full scaleexhibition, speed networking sessions and sitevisits.

"The focus this year will be to examine whatis needed in order to scale up the delivery ofpassive house in the UK whilst at the same timemaintaining high quality standards, includingdetails of the first schemes with over 100 homes,and leading-edge passive house retrofit proj-ects," said Jon Bootland, chief executive of thePassivhaus Trust.

The conference will include sessions on de-livering passive house at scale, new project case

studies for 2013, and the successful deliveryof passive house projects.

Speakers will include architect Marion Baeliof Paul Davis & Partners, Jane Barnes ofconstruction consultants Davis Langdon, JustinBere of Bere Architects, the Green BuildingStore's Bill Butcher, Ian Byrne of the NationalEnergy Foundation, passive house consult-ant Nick Grant, architect Jonathan Hines ofArchihaus, and Tomás O'Leary of the PassiveHouse Academy.

The day will include site visits to the HowePark passive house and to Energy World, apioneering development of low energy homesand offices that dates from the 1980s.

The conference is run by the Passivhaus Trustand the BRE. Munster Joinery are the leadsponsors, while other sponsors include Ac-credited Passivhaus Design, Beattie PassiveNorse and Internorm UK. The event is alsosupported by the AECB, the Good Homes Al-liance and the University of Nottingham.

Opportunities for sponsorship and exhibitingare now sold out. The confirmed exhibitors areAirflow Developments, Ambiwood, Daylight &Ventilation Solutions, Ecohaus Internorm,Ecological Building Systems, Ecology BuildingSociety, Green Building Store, Isoquick, Magmatech,Passivhaus Homes Ltd. & Saint-Gobain.

(above) Delegates relaxing after a busy day of learningat the 2012 UK Passivhaus Conference

Packed schedule for October's one day Passivhaus Conference

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News

Changes needed to kick-startGreen Deal, lender warnsThe UK government must make urgent changesto the Green Deal to increase public demand,a leading green lender has warned.

Figures released by the Department of En-ergy and Climate Change in July showed thatonly 36 of the 45,000 households assessedso far under the Green Deal have signed upfor energy upgrade work. Energy ministerGreg Barker had previously predicted that theinitiative would stimulate up to 10,000 up-grades per year.

According to Ecology Building Society CEOPaul Ellis, the scheme must be improved todrum up interest. “We’re disappointed but notsurprised by these results,” he said. “The ur-gent economic and environmental need tomake our homes more efficient isn’t matchedby demand from homeowners, and the in-centives provided by the Green Deal justaren’t enough to create this market. We needto see a more competitive interest rate, a sim-pler process and wider policy initiatives todrive take-up, such as an energy efficiencyfeed-in tariff, council tax or stamp duty dis-counts.

Ellis said that the banking sector also had akey role to play in stimulate demand. “Banksand building societies have their role to play,too,” he said. “Our C-Change retrofit discountshave led the way in showing that mortgagelending can support people to reduce theirhome’s carbon emissions. Now we need othersto follow suit.” Ecology’s C-Change mortgagesoffer 1% interest rate reductions for homes

that meet standards such as passive houseand Enerphit.

“This isn’t just about being green – in an eraof rising fuel costs, it’s about a sensible longterm approach to finance,” he said. “We nowknow that a higher EPC rating can have areal impact on a home’s selling price, and ev-idence from the US suggests that mortgageson energy efficient homes are less likely to

default.”

According to Russell Smith, managing direc-tor at energy upgrade specialists Parity Proj-ects, the Green Deal has a role to play, but isonly ever likely to be one of many finance so-lutions for retrofit. “Historically much of ourwork as an independent and impartial adviserhas come from households who see energyefficient retrofit as simply one part of a widerproperty renovation project,” he said. “Forthose people, the Green Deal simply doesn’trepresent good value, nor is it well suited tomore complex projects.

“If we are to achieve the scale of retrofit re-quired to meet the UK’s climate and energyobjectives it is imperative that there are alter-natives that cater for all-comers, and as theGreen Deal starts to find its feet we are seeingthese emerge. We like to think that our workwith Ecology blazed a trail in that respect,with our Home Energy Masterplan service of-fering a high-quality alternative to Green Dealassessments and their C-Change discountsrepresenting a viable alternative to GreenDeal finance.

Of course having a range of retrofit “routes”out there is not only good for households –giving them greater choice – but is also greatfor businesses who can’t afford to wait for theGreen Deal to create a market for their services,”Smith said.

Ecology CEO Paul Ellis (above centre) has called forchanges to the Green Deal to stimulate demand

Designed by Cartwright Pickard Architects,Octavia's Sulgrave Gardens is London’s largestmixed-use passive house scheme to date,costing £1,821 per sq m to build. The 2,855square metre development, now being mar-keted as 'The Greenhauses', comprises 30mixed tenure apartments and houses, includ-ing thirteen shared ownership, nine affordablerent and eight 2/3 bed private townhousespriced from £750,000 up – seven of whichhave already been sold.

Established by Octavia Hill, the Victorian socialreformer and founder of the National Trust,Octavia has become a prominent housing de-

velopment organisation managing a portfolioof high quality and sustainable homes in CentralLondon. Octavia have a strong track recordfor building award winning schemes with afocus on social and environmental sustain-ability. Their upgrade to 100 Princedale Road– a mid terrace listed Victorian building in aconservation area which became the UK’sfirst upgrade project to achieve full passivehouse certification – featured in issue threeof Passive House Plus.

(right) Sulgrave Gardens is London’s largest mixeduse passive house development yet built

Homes at London mixed-usepassive scheme selling well

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News

Princedale launches cladding system formulti-storey passive housePassive house specialists Princedale Homeshave announced the launch of a compositecladding system for multi-storey passive houseconstruction onto the UK market. Accordingto Princedale director Bram De Bruycker – apioneer of the Belgian passive house move-ment – the system delivers a fully clad, air-tight, insulated, breathable building envelopeto passive house standard for concrete andsteel framed buildings – with windows andbuilding services pre-installed.

Developed over seven years, the system wasdesigned specifically for multi-storey passivehouse construction in Belgium and has beenused for offices, schools, high-rise accom-modation (in particular social housing) andpublic buildings. The company said that it isalso flexible enough to reflect a wide varietyof architectural styles, preserving the architect’soriginal vision.

According to De Bruycker, Princedale designsand manufacturers each system to the architect'srequirements, and takes responsibility for theinstallation and delivery of the airtight buildingenvelope. “The system will continually evolveand improve with each iteration, ensuring eachproject is constructed with the most up to datesolutions possible,” he said.

De Bruycker said the company starts with de-tailed technical design and planning to ensurethat any issues with airtightness, thermalbridging, condensation and insulation arepre-empted and designed out before work onsite begins. “The panels are then millimetre-precision prefabricated,” he said, “includingpre-installation of windows and the applica-tion of external cladding such as render, timber,metallics or brick slips, ready for delivery tosite.” Installation is designed to be fast andefficient utilising a small team, even on large

buildings, and no scaffolding is required.

The system is capable of delivering a U-valueof 0.1 to a large building, delivers a fully airtightbuilding envelope, and is designed to eliminatebuild-up of interstitial condensation. It is factorymanufactured and can accommodate a rangeof insulation thicknesses.

Princedale’s composite cladding system has previouslybeen used on several certified passive house projectsin Belgium including the five-storey Molenbeek socialhousing project (above) and nine storey offices forBelgian electricity utility Elia (left)

Passive house training provider Target Zerois planning a tradesperson course to run inEngland in November. The one week course– which covers building envelope and services– has been prepared in advance of the certifiedpassive house tradesperson exams on 29 No-vember. Discounts are available where companiessend multiple attendees.

Target Zero provides Passive House Instituteaccredited training, including certified passivehouse designer courses in addition to the trades-person courses.

The company runs the passive house designercourse over ten days, while the tradesperson

course includes both the building envelope andbuilding services modules and is held overfive days.

"As of this year we haven't had any failures onany of the courses," said Target Zero's DarrenO'Gorman. He told Passive House Plus thata lot of the training he provides is in-house tocompanies or institutions. Target Zero alsoprovides training in thermal bridge analysis.

O'Gorman recently delivered the passive housetradesperson course to faculty staff at SouthWest College, Omagh. The college offers coursesin sustainable construction, building services andarchitectural technology.

O'Gorman is now returning to the college todeliver the passive house designer course. Hewill also be delivering the tradesperson courseto a window company in Scotland later this year.

He also told Passive House Plus that the firsttwo certified passive house tradesmen in theUK were in fact trained in Ireland by Target Zero.

O'Gorman became interested in passive housedesign in 2005 when he bought a cottage him-self and renovated it to a low energy standard.

The company recently opened a new Irish trainingcentre at the Campus Innovation Centre, ITCarlow.

Target Zero to host passive house tradescourse in November

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News

A house or office designed to be so energyefficient that it doesn’t need a conventionalheating system sounds great in theory – butwhat’s it like to be in such a place?

From 8 – 10 November 2013, owners andresidents of passive buildings are being urgedto help the public answer that question by openingtheir doors for the 10th annual InternationalPassive House Days.

At the UK Passivhaus Open Days, visitors will havethe opportunity to experience the comforts ofthe passive house standard first hand. A rangeof projects designed by different architectsand built using various construction methodswill be open to the public including private houses,social housing, community buildings, officebuildings and refurbished properties.

The event is organised by the Passivhaus Trustin conjunction with The International PassiveHouse Days set up by the International PassiveHouse Association (iPHA). The iPHA event iscurrently in its 10th year and will have projectsfrom all over the world open to the public.

To participate in the International Passive

House Days, register your project with theInternational Passive House Database atwww.passivehouse-database.org

Registration is free of charge. Detailed registrationinstructions can be found on the iPHA website.

If you have a passive house – either underconstruction or complete – that you’d like to openup to visitors during 8-10 November visit bit.ly/1czilt9

for details on how to register your project.

As the event draws close, participating projectsin the UK and internationally will be listed onwww.passivhausprojekte.de/projekte.php

Hadlow Rural Regeneration Centre, Tonbridge (left)and the Denby Dale Passivhaus (right) were two oftwelve UK passive house projects to open their doorsfor the 2012 International Passive House Days

Passive houses to open doors from 8-10 November

Heliotherm releases Android app for remoteheat pump control

Heliotherm has launched HelioDroid, an An-droid app that enables users to control theirHeliotherm heat pump remotely wherever aweb connection is available.

The app allows users to view heat pump per-formance data, and to adjust operating modes androom temperatures. Any errors are immediatelyand automatically reported by a signal to the mobilephone user, without having to open the application.

HelioDroid was developed by Heliotherm's ownresearch and development headquarters. Thecompany's CEO Andreas Bangheri has alsoconfirmed that an iPhone version of the app iscurrently in development.

Heliotherm was founded in 1987 by Bangheriand has been based in Langkampfen, Tyrol,Austria since 2007. With a workforce currentlyconsisting of 65 employees, the company "fo-

cuses exclusively on the development and pro-duction of high efficiency heat pumps".

To date more than 25,000 of its heat pumpshave been installed, and about 75% of the heatpumps it manufactures are exported.

(above) Austrian heat pump manufacturer Heliotherm’sbase in Langkampfen, Tyrol


News

Devon, Lancashire and Wales win at UKPassivhaus Awards

The winners of the 2013 UK Passivhaus Awardswere announced at a ceremony at the residenceof the Austrian Ambassador in London on 4 July.

The Totnes passive house B&B emerged asthe winner in the private housing category. Thisdeep retrofit and extension to a modernist cavitywall house in Devon achieved the seeminglyimpossible: full passive house certification foran upgraded building. The project predatedthe creation of the Passive House Institute’sstandard for upgrade projects, Enerphit.

The Lancaster Cohousing project in Lancashirewon in the social/group housing category. Thisdevelopment features 41 certified passivedwellings, 35 of which are part of a cohousingcommunity that shares facilities including com-

munal kitchen, dining area, and outdoor spaces.

In the non-domestic category, the CanolfanHyddgen local authority office building and IT train-ing facility in Machynlleth, Wales, was victorious.

All three projects are the subject of detailedcase study articles in this issue of Passive HousePlus. Other shortlisted projects such as Plum-merswood, Ditchingham and Green Base havefeatured in previous issues.

The full list of shortlisted projects for this year’sawards were: Private Housing (sponsored by Ecology BuildingSociety): Crossway, Hawkes Architecture Ltd;Plummerswood, Gaia Research; Totnes Pas-sivhaus, Passivhaus Homes Ltd.

Social Housing (sponsored by Kingspan InsulationLtd): Ditchingham Passivhaus, Parsons & Whittley;Lancaster Cohousing Project, Eco Arc Architects;Racecourse Passivhaus Bungalows, by Gentoo.

Non-domestic (sponsored by Munster Joinery):Canolfan Hyddgen, JPW Construction; GreenBase, Simmonds Mills Architects; InterserveOffice, Interserve.

Pictured (l-r) are private housing finalists Prof SandyHalliday, Gaia Architects; Richard Hawkes, HawkesArchitecture; Jon Lee, Ecology Building Society; awardwinners Adam Dadeby & Janet Cotterell, PassivhausHomes Ltd along with Bouke Martinot of the Totnespassive house build team; and Jon Bootland, PassivhausTrust

Irish manufacturer ProAir has just had its PA600LI heat recovery ventilation unit listed on theSap Appendix Q database with some of the bestresults on the market.

In independent tests carried out by BRE, theunit achieved a specific fan power of 0.57, andheat recovery efficiency of 94%.

"We're up there with the best," said ProAir's DavidMcHugh. “Only one other unit on the list is abovethis at 95% and that is a Paul unit, but this sameunit has a lower SFP rating, so if one takesthe combined high thermal and electrical effi-ciency in combination the PA600 LI could bedescribed as the most efficient on the market.”

McHugh explained that the PA600 LI is made

from high density polyethylene foam. "The ad-vantage of that is that it makes for a very well-sealed unit and this contributes to its highefficiency. In addition, this is also one of thequietest on the market as all the componentsare suspended within the foam," he said.

McHugh said that the high insulation value ofthe foam means that it’s ideal for use within thethermal envelope, but can also tolerate beingin a cold attic space if necessary. At a weightof only 27kg it can be installed by just oneperson, he said.

(right) ProAir’s PA600 LI MVHR system has achieveda Sap Appendix Q rated heat recovery efficiency rateof 94%

ProAir gets high marks on Sap Appendix Q

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News

On 7 and 8 June the first ever Insulation Blow-ing Symposium took place at the factory of X-Floc, the German manufacturer of insulationblowing machines, in Renningen, Germany.Among the guests were installers, manufactur-ers of blown insulation machines, insulationmaterial manufacturers, retailers, and repre-sentatives of research and education.

Axel Greiner, CEO of X-Floc said: “The BlowingInsulation Symposium is the first public plat-

form for all stakeholders. The development ofblowing and injection techniques reaches asimilar degree of innovation to the use of plas-tering machines or concrete pumps on buildingsites.”

Visitors to the symposium had the opportunityover the two days to learn about the differentmethods for the injection of blown thermal in-sulation materials. The audience included visitorsfrom Russia, Chile, France, Great Britain, Latvia

and Canada. Powys-based Warmcel suppliersand installers PYC Systems were in attendance.

Various demonstrations were held for differentapplications including on-site situations andfactory filling methods. Both mobile and stationaryblowing insulation machines were on show.

Seminar presentations focused on the stateof blown insulation technology and its futuretrends. The speakers ranged from experts infibre insulation manufacturing to building productmanufacturers such as the company Hufer,which presented its Smart Six system of rafterexpanders and add-on constructions.

Moreover X-Floc gave all manufacturers ofblown insulation materials the opportunity topresent their products – 65 different productsincluding cellulose, wood, glass, rock, sheepswool, EPS, grass and coconut husks.

According to X-Floc the feedback was over-whelmingly positive, and the company saidthat for the first time stakeholders could feel a"team spirit" in the blown insulation industry.The professional dialogue was informativeand enriching for all participants, according tothe company, and X-Floc have said the eventwill be repeated in future years.

(above) A timber cassette being filled with wood fibreinsulation via an X-Floc J-jet ventilated rotary nozzle

X Floc hosts first ever blown insulation symposium

Zephair launches DIY unit for finding air leaksRenowned Irish airtightness consultant MarkShirley has announced the launch of theZephair Pre Pro, an "easy to use and reliableway to perform quality control of your airtightlayer by under pressurising a building".

This DIY system is designed to allow users tofind air leaks in the building envelope beforean airtightness tester comes on site.

“Air is free. Uncontrolled air is expensive,”said Zephair's Mark Shirley. "As the buildingis being under pressurised you can walk thebuilding and find the cracks & gaps in thecontinuous airtight layer. Once you haveachieved 50 Pa pressure and you can nolonger find any leaks in the envelope thenyour building, or part of the building, is readyfor testing."

The Pre Pro is designed to fit into either aninward or opening window or door.

"The Pre Pro is easy to set up and operateand you can start looking for leaks within 10minutes of starting to build the device into awindow or door," Shirley said.

The Pre Pro has a dial that shows the pressuredifference between the outside and inside ofthe building. "If you can achieve a 50 Pa pres-

sure difference with the Pre Pro, you can beconfident that when the professional testerturns up they too will be able to achieve thepressure threshold required to test to the rel-

evant standards," he added.

The Zephair Pre Pro is designed and manu-factured in Ireland.


News

Airflow launches enhanced online trade counterin website revamp

Airflow Developments has launched a new websitethat reflects its increased range of ventilationsolutions and offers a new ‘quick order’ facilityfor trade customers.

The new site takes into consideration the manyneeds of the UK ventilation market and demon-strates the breadth of Airflow’s solutions – whichincludes no fewer than nine passive house

certified MVHR systems under the Duplexventrange. The homeowner section looks specificallyat the Green Deal and how vital ventilation isto the long-term success of highly insulatedbuildings. It also gives advice on what type ofextraction fans meet the Green Deal criteria, sohomeowners can be as informed as possible.

For the electrical wholesaler, the quick order padfunction means easier placing of orders and fasterturnaround time. Using predictive technologyit monitors previous customer order patternsand intuitively adds their fast moving products tothe order pad. This is in line with the changingways in which the distribution market is conductingtheir business. John Kelly, marketing managerof Airflow Developments said: “We know ourcore wholesaler customers are increasingly usingEDI technology both mobile and online in theirday-to-day jobs, and as one of the leading UKventilation manufacturers we have respondedto this shift.”

The new site also takes the increasing importanceof a social presence with links to the company’sFacebook, Twitter and You Tube channels, socustomers can share and comment on theirexperiences with the customer services teamat Airflow.

(above) Airflow’s revamped website reflects the company’sbroad range of low energy ventilation options

Leading pre-fabricated timber frame builderHanse Haus recently completed their latestproject featuring JG Speedfit underfloor heating– a passive house in Oddington, Gloucestershire.

The main active heating source for the 236 squaremetre, four-bedroom house is a ground-sourceheat pump. The system uses a vapour com-pression cycle, where pumps take low-gradewarmth and concentrate it to a higher tempera-ture that is then used to heat up the building.

Due to the low temperature flow at which theheat pump operates, underfloor heating wasdeemed ideal for distributing warmth through-out the house.

Being the sole plumbing and heating contractorfor Hanse Haus for the UK, Synergy PHR hasappointed JG Speedfit as the exclusive supplierof the underfloor heating system installed.

Darren Farley, director of Synergy PHR com-mented: "Since partnering with Hanse Hausin May 2012, Synergy have carried out instal-lations in seven properties in the UK all withfull ground and first floor underfloor heatingby JG Speedfit. We have used both stapleand over fit systems that proved to be veryeasy to install, saving time and effort. The co-

operation with the push-fit people was verysatisfying from the initial contact with theirsales representative, through to CAD specification,delivery and installation. On completion, the JGSpeedfit engineers and technical support werealways there to help with system setup, testingand control."

JG Speedfit assisted throughout all projectstages, with a particular focus on pipe layoutdesign and installation advice.

Farley continued: "Synergy currently have sevennew jobs to complete with JG Speedfit in 2013covering the UK, Scotland and the Channel Islands.I am looking forward to these and more suc-cessful projects in collaboration with Speed-

fit, using their superb products and services."

According to JG Speedfit, the philosophy behindtheir underfloor heating model is similar to thephilosophy behind the Hanse Haus concept —innovation towards energy preservation and effi-ciency, comfort, aesthetics and value for money.

JG Speedfit underfloor heating offers various ad-vantages, according to the company, includinglow temperature operation, simple installation,even temperature distribution, an unobtrusive anddiscreet circuit, multi-zoning, and compatibil-ity with a wide range of heating technologies.

(above) The Hanse Haus passive house in Oddingtonfeatures a JG Speedfit underfloor heating system

JG Speedfit specified for passive Hanse Haus

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News

Pro Clima products get NBS spec clausesEcological Building Systems has announcedthat the Pro Clima range of airtightness andwindtightness building products now have NBSspecification clauses.

"While it is essential to ensure that materialsspecified to attain airtightness are suitable andlong lasting, it is also critical to provide a clearspecification," says Penny Randell of EcologicalBuilding Systems.

"Accurate specification is fundamental to thesuccess of an airtight building project and thedesign stage detailing is critical to ensure thattargeted air permeability rates are achieved.As passive house specifiers and designers arewell aware, unless clear and precise specifi-

cations are written and then fully interpretedto the whole project team costly errors canoccur if remedial work has to take place."

She continued: “The Pro Clima range has thesolution for every critical airtight and vapourcontrol junction. Gaining NBS now makes thewhole system much easier to specify for ar-chitects and is just another step in our pro-gression and commitment to working activelywithin the specification market.” The Pro Climaproducts are also featured at ribaproductse-lector.com

Ecological Building Systems are the sole agentsfor Pro Clima in the UK and Ireland, with theproducts sold via trained stockists.

Market penetration of the passive house stan-dard will be facilitated by easier availability ofsuitable products, a leading window manufacturerhas said.

According to Munster Joinery, the market de-mands products that have the required per-formance, are affordable and meet customerexpectations. “Windows and doors are ahuge part of any passive build and performance,affordability and versatility are key criteria,” saidMunster Joinery marketing manager Gemma Ring.

“Traditionally passive house certified windowswere high on performance but expensive andoffered little choice. We’re working to makethe dream of the passive house build univer-sally achievable.”

With five window ranges certified by the PassiveHouse Institute in Germany the customer isoffered a wide range of colour, material andoperating system options. “The customer nolonger needs to compromise on style to achieveperformance,” Ring said.

The company’s passive range feature tripleglazing with multiple panes of low emissivityglass and cavities filled with low conductivitygasses such as argon or krypton. Edge lossesare reduced to a minimum by the use of warmedge spacer bar. All frame sections have aninsulating core and are designed so as to elim-inate thermal bridging at all critical points.

“Passive windows are normally a huge part ofthe passive spend so the competitively pricedMunster Joinery offering makes the passiveproposition a lot more generally accessible,”said Ring. “Munster Joinery brings the threekey factors – performance, affordability andversatility to the market.”

Munster Joinery has grown since its foundationin 1973 to rate among the largest manufac-turers of energy efficient windows and doorsin Europe. Now operating in Great Britain, Ire-land and Northern Ireland the company is alarge employer with two large manufacturingplants, including a 230,000 sq ft manufacturingfacility in Warwickshire and a further 910,000 sq ftproduction facility in Ireland. “Munster Joineryhas the capacity to deliver passive productspromptly,” said Ring.

According to Ring, Munster Joinery is committedto reducing its environmental impact, such asemploying efficient waste management tech-niques to reuse and recycle waste so thatonly minimal amounts go to landfill. The companyhas invested heavily in sustainable energysolutions such as wind turbines and a CHPplant. “This gives rise to an annual saving ofmany thousands of tonnes of carbon,” saidRing, adding that the company’s purchasingpolicies favour green materials. Timber is re-sponsibly sourced and the company has chainof custody certification to both FSC and PEFCstandards.

(above) Munster Joinery’s Dublin showroom

Passive house needs greater choice– Munster Joinery

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News

Topseal gets ISO 14001 environmental certificationLeading roofing manufacturer Topseal hasachieved ISO 14001 certification for environ-mental management. This is an internationalstandard that provides companies with practicaltools to reduce their environmental impact.

Topseal is a fibreglass roofing and waterproofingsystem that comes with BBA Certification and anup to 30 year guarantee. Designed to providewaterproof protection for 100 years or more, it’s alsoavailable as a complete green roof system, knownas Topseal GreenTop. The timber decking usedwith Topseal is from fully FSC-certified sources.

Topseal manufactures its core products in theUK and aims to source materials in the UKwhere possible too. The company's roofingmaterials have a BRE Green Guide A ratingfor domestic applications, and an A+ rating forcommercial ratings.

Topseal can be installed for regular roofs, greenroofs, balconies or walkways, and even poolsand ponds.

"Topseal GRP can be designed to practicallyany size and shape," Topseal's Vicki Smith toldPassive House Plus. The product is installedthrough a national network of trained and approvedinstallers.

Topseal also has ISO 9001 quality management

certification. The product is applied without theneed for heating, helping to make installationsafer and more energy efficient. It is also re-cyclable once its service life is finished, and is

compatible with roof mounted wind turbines,solar panels and roof lights.

(above) The Topseal Green Top green roof system

Leading designers of care homes and extra careflats The Tooley & Foster Partnership havelaunched a subsidiary, Accredited PassivhausDesign, to provide passive house design andenergy calculation services. The firm's goal is tohelp designers create buildings with deliverablelow running costs and great comfort for residents.

Certified passive house designer Peter Rankensays that building to the passive house standardis ideal for care homes, as comfort and low energyuse is included for the lifetime of the buildingwithout relying on bolt-on technologies. "This isa win-win for residents and building managers– with filtered air, no draughts and even sur-face temperatures, residents don’t have to worryabout getting too cold or too hot," Ranken said.

"For the care home operator, heating bills areminimised, and future upgrades to cope withrising fuel bills are not necessary. The extracost of building and certifying to the passivehouse standard can be offset by reduced billsin about eight years, or less if fuel costs continueto increase."

Unlike most houses, care homes and extracare flats are occupied and heated 24 hoursa day to keep internal temperatures comfort-able for frail residents. With conventional carehomes this can give very high running costs,as the heating is turned up to compensate fordraughts and low surface temperatures. Thepassive house approach designs out theseproblems.

According to Ranken, Passivhaus Design seesthe adoption of the passive house standard asessential to meet four future challenges: de-mographic change with increasing numbersof elderly people, future fossil fuel shortages,legislation to reduce carbon dioxide emissions,and cost certainty with reduced running costs.

"Our past experience of ‘bolt-on’ eco technologiesshows that they can be unreliable and do notdeliver the energy and fuel savings promised,Ranken said. “Passive house is more robust andwe can confidently recommend it to our clients."

(above) An illustration of an Accredited PassivhausDesign extra care scheme in the Cotswolds designedto the passive house standard

Leading care home designers launch new passive house firm

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News

Passive house consultant designslow impact lampWhat do passive house consultants get up toin their spare time? In the case of Nick Grant,it’s ecological industrial design.

One of the leading lights in the UK passivehouse sector, Grant has teamed up withartist-metalworker Colin Chetwood to designand manufacture Lock Lamp, a low environ-mental impact task light created with the aimof combining aesthetic appeal and practicaldesign.

The hand crafted lamp was designed to com-prise minimal materials; steel, nickel, birchply and aluminum combined to achieve a slimproduct that has both strength and flexibility.

The lamp’s positioning mechanism has beendesigned with ease of operation in mind. Thelight is extended, raised and rotated abouttwo axes and is locked into place by gravity,without the use of springs, counterweights orscrew clamps. It is designed specifically towork with bulky and heavy energy-efficient lampsincluding CFLs and LEDs.

Grant and Chetwood first worked together todesign the light fittings for award-winning pas-sive house architects Architype. Their frus-tration with available task lighting options ledto the creation and development of LockLamp in their Herefordshire workshops.

Further information on lighting from Grant andChetwood is available from www.locklamp.com

The Passive House Association of Ireland hasannounced that Passive House Institute founder& scientific director Prof Wolfgang Feist will bethe keynote speaker at this year’s annual 'SeeThe Light' Irish Passive House Conference.

The event will take place on Friday, 25 Octoberin Dublin Institute of Technology, Bolton Street.

The PHAI said the visit of Wolfgang Feist willprovide an excellent opportunity to run an academicstream for papers on the topic of passive houseand low energy buildings research in Ireland.

“The event will provide the passive house com-munity with a setting in which to showcase itsresearch,” said PHAI chairman Martin Murray.“It will also provide a forum to showcase op-portunities for further co-operation in passivehouse research in Ireland.”

Half page abstracts are sought by the first weekin September to enable the committee to selecttopics for presentation, and all topics are openfor consideration. Potential topics to date include:

passive house education at second and thirdlevel in Ireland, passive house and thermal bridgeanalysis, passive house and hygrothermal analy-sis, suitability of the building stock for energyretrofit, and seasonal thermal energy storagein combination with heat pumps.

For further information see www.phai.ie

(left) Passive House Academy founder Tomás O’Learyannouncing the release of a new version of the PassiveHouse Planning Package (PHPP) software at See theLight 2012

Wolfgang Feist to speak at See The Light 2013

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(above) The MK2 lamp features a steel base and ply shade; the LED desk lamp (inset)

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As many Passive House Plus readersare aware, Part L1A of the buildingregulations deals with energy efficiencyand renewable energy requirementsfor new dwellings and is the Britishgovernment’s key reference documentguiding England and Wales towardsmeeting their 2020 carbon commitments.The building design and constructioncommunity need to know this documentalong with the various energy modellingprogrammes in order to achievecompliance. An updated version ofPart L1A was introduced in 2010, ata time when activity in the constructionsector hit an all-time low and when manydesigners and contractors may havebeen out of touch on exactly what’s re-

quired of them. In addition to knowingwhat’s included in Part L1A, it’s alsocritical to know what’s excluded interms of everyday comfort attain-ment and real energy consumption.

The U-values required in the UK aresignificantly lagging behind those re-quired in its nearest neighbour, Ireland– in some cases by as much as 42%.The backstop U-values in England/Walesand Ireland respectively are 0.20 and0.16 W/m2K for roofs, 0.30 and 0.21W/m2K for walls, 0.25 and 0.21 W/m2Kfor floors, and 2.00 and 1.6 W/m2K forwindows. If serious progress is to bemade towards achieving nearly zeroenergy buildings in the UK by 2020,these U-values are going to have to

reduce significantly over the comingyears. There’s also considerable roomfor improvement on airtightness levelsrequired in Part L1A, currently standingat 10m3/hr/m2 compared to a margin-ally better 7m3/hr/m2 in Ireland.

A recent study by the Passive HouseAcademy modelled three house typestypically found in Ireland in the Deapsoftware – the Irish equivalent ofStandard Assessment Procedure (Sap)2009 used in the UK – to explore dif-ferent routes to energy efficiencycompliance. The study used a 127 sq mbungalow, a 151 sq m two-storey de-tached house and a 114 sq m semi-detached house and applied multiplescenarios which included what welabelled ‘backstop house’, ‘high-per-formance envelope house’ and ‘heatpump house’.

In the backstop house, we modelledall the minimum backstop values forinsulation, windows, airtightness andrenewable energy and used a gas boileras the heating source. In all threecases, the houses failed to meetboth the energy efficiency and carbonemissions requirements – which inIreland both stand at 60% reductionscompared to our 2005 building regu-lations. So if you’re using a traditionalheating system such as gas or oil,the backstop U-values listed abovecome nowhere close to compliance.I wonder just how many designers andbuilders in Ireland are aware of this.

Next we modelled our high performanceenvelope scenario to see what wouldbe required for compliance if using aboiler and found that near passive houselevels of insulation and airtightnesswould be needed for all three housetypes, with U-values of 0.13 for opaqueelements, 1.2 for windows and doorsand an airtightness of 1.0m3/h/m2).From a detailing and constructionperspective, achieving compliance inthis case is considerably more challengingthan would be required with just thebackstop values.

Our next analysis swapped out a tra-ditional boiler for a high-efficiency(COP of 4.44) electric heat pump and,to our surprise, compliance could beachieved for all three house types withjust the backstop values for insulation,airtightness and renewable energy

(Ireland’s regulations for new homesmandate a renewable energy contri-bution of 10 kWh/m2/yr thermal energyor 4 kWh/m2/yr from microgeneration).It seems that the choice of heatingsystem thus trumps insulation andairtightness levels in terms of compli-ance, and that a leaky building withmodest levels of insulation is an ac-ceptable form of construction in 2013.

I can’t help but wonder whether theenergy efficiency regulations in the UKare falling short on ensuring thermalcomfort for building occupants. Theset temperature in Sap 2009 for livingspaces is 21C and just 18C elsewhere.The Passive House Academy recentlymodelled nine different dwellingtypes commonly built in Ireland andworked out the average temperaturefor each dwelling using the abovetemperature requirements. The pro-portion of living area ranged from 9to 35% across the nine buildings,and the overall average whole-housetemperature provided for emerged at18.5C. This falls considerably short – by1.5C – of the whole-house temperaturerequired in passive house. At firstglance that temperature differencebetween Part L1A and passive housemight not seem much, but when youconsider that the latter also ensureswarmer surfaces (achieved throughbetter U-values in opaque elementsas well as windows), greatly reducedthermal bridges and some 20 timesbetter levels of airtightness, the comfortlevels provided by the two approachesare, frankly, worlds apart.

Let’s consider next the duration of timethat the above average temperatureof 18.5C is ‘required’ in the dwelling.During weekdays in the heating sea-son, it’s assumed that the house isheated for just eight hours per day,doubled at the weekend to 16 hours toreflect the likelihood that occupants areat home for longer periods. It strikesme, however, that there are vastnumbers of households where 18.5C forjust eight hours per day is far removedfrom the thermal comfort requirementsof real families in real houses. In otherwords, I suspect that the building’sEPC in many cases will not be a truereflection of either comfort levels inthe dwelling or actual energy bills –or, most likely, both. Incidentally,comparing the heating period duration

Will nearly zero energy buildingsresult in a thermal comfort deficit?

As the UK inches towards zero carbon and nearly zero energy building targets, the construction industrymust pay increasing attention to the impacts of regulatory changes on design and construction, arguesPassive House Academy founder Tomás O’Leary. But will homes designed using the UK’s nationalmethodology come close to passive house levels of comfort?

“If serious progress isto be made towardsachieving nearly zeroenergy buildings in theUK by 2020,U-values have to reduce significantly.”

in the UK and Ireland unearthed acurious anomaly insofar as sixteenhours at the weekend is assumed inthe former, compared to eight hours inthe latter. This difference, if borneout in reality, would amount to con-siderably higher energy consump-tion in the UK compared to Ireland.My own expectation, however, is thatthe thermal comfort expectations issimilar in both countries and that theUK energy modelling approach ismore plausible. The time and temper-ature settings for heating in passivehouse are far more predictable and,for me, more representative ofwhat’s needed in reality – namely 20C,24 hours per day, 365 days per year.

As a very fortunate resident in a passivehouse since 2005, I’m often askedwhether 20C is warm enough in thecold winter. Behind this question is, Ican only conclude, an admission onthe part of the enquirer that such atemperature in conventional dwellingsfalls below par in terms of thermalcomfort. The design temperature of20C in a passive house is the operativetemperature, an average for both airas well as surfaces. If you live in aconventional dwelling where the airtemperature is 20C but the surfacetemperature of glazing is, say, 14C,temperature stratification will resultand comfort will be impaired.

In my view, therefore, the time andtemperature assumptions in Sap, iffollowed precisely, would result inwhat might be referred to as a com-fort deficit.

Another fact that that has puzzled mefor quite some time is that just oneclimate data source is used to modelthe energy balance for dwellings acrossEngland and Wales. In Sap 2009 thelocation of 53.4ON is used to modelsolar gains for example, equivalentto Liverpool. But what if you’re locatedconsiderably further north or indeedsouth of Liverpool? Surely the solargains in Plymouth, some 250 milesto the south would be significantly

more, contrasted with Newcastle to thenorth which would be somewhat less.Sap also refers to just one set of monthlyexternal reference temperatures forEngland and Wales, which has avery significant bearing on transmissionand ventilation losses. Compare thiswith passive house which has over 22detailed climate datasets for the UK.

So what can we learn from the abovereview?

All European nations are on the roadtowards what’s referred to as ‘nearlyzero energy buildings’ by 2020 (bythe way, I think it’s quite hilarious toinclude the term ‘nearly’ in a Europeanpolicy directive – don’t you?). But theprocess and programmes by whichwe quantify the energy consumptionof dwellings are, in my opinion, ratherblunt instruments and the comfortdeficit highlighted above will almostcertainly guarantee that the real energyconsumption (and carbon emissions)of your dwelling will be considerablyhigher than that suggested on yourenergy label. So-called ‘nearly zeroenergy buildings’ of the future mightactually be far from that in reality.The variances in energy modellingmethods used in different Europeancountries is also regrettable in myview and will prevent us knowing

whether a ‘nearly zero energy building’in Ireland bears any relation to onein the UK or Denmark.

Part L1A and Sap are the buildingrules by which everyone must abide– in that respect this system is fairinsofar as it provides a level playingfield. I have a strong suspicion, however,that the design, construction andhome-owner community are not fullyaware of what exactly is included orexcluded in the game, however, andthe sooner we all get up to speed thebetter. If we continue on the currentpath, the claim in Europe that we livein nearly zero energy buildings willsmack of the Emperor’s new clothes.

My own preference would be to adopta system which uses a scientificallyrigorous approach right across Europe(or the world for that matter) andwhich has a proven track record indelivering high comfort no matterwhat the climate. It’s sitting there onthe shelf and is called passive house.

Passive house is already mandatedin the city of Brussels from 2015 – thevery city that is home to the EuropeanCommission which issued the EnergyPerformance Building Directive and thecall for nearly zero energy buildings.Isn’t that more than just a little ironic?

Follow us on Twitter and tweet your thoughts to @phplusmag

Here’s a sample of our recent tweeting, along with tweets

and threads of tweets that caught our eye.

CPWSeattle @CPWSeattle World Bank reports that today’s energyuse would be 36% higher without efficiency gains of the last 20 yrs.

Paul Price @swimsure @CPWSeattle Efficiency good but carbon in-tensity of global GDP is unchanged in 35 years. Efficiency 'savings'are spent on CO2!

TreeHugger.com @TreeHugger Just thrilled to discover new mag onPassive Houses @phplusmag, so much to steal! http://goo.gl/u2LbE

Lenny Antonelli @lennyantonelli Thanks to @lloydalter for pluggingmy blog post for @phplusmag on 'passive house vs passivhaus' at@treehugger yesterday http://goo.gl/u2LbE

Passive House Plus @phplusmag Unbelievably, we've had 4 UK enquiriesin today on projects worth a combined £228 million! #passivehouse#passivhaus #greenshoots

Munish Datta @MunishDatta Unique building block made of recycledmaterials captures more carbon dioxide than is emitted during its manufacturehttp://ow.ly/1ZoIZy

Passive House Plus @phplusmag UK govt plans: allow carbon offsetsin supposedly zero carbon homes, as explained by @EnergistUKhttp://bit.ly/1eRCfyG #allowablesolutions

Passive House Plus @phplusmag What would it look like if the UKgovt used its #allowablesolutions approach for "zero carbon" homes inother policy areas?

Passive House Plus @phplusmag EG don't push industry to greenproduction. Shut ‘em down, buy imported goods & the carbon is anothercountry's problem! #allowablesolutions

“I can’t help butwonder whether theenergy efficiencyregulations in theUK are falling shorton ensuring thermalcomfort for buildingoccupants.”

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comment

The headlines are screaming. TheEU:ETS – the European carbonemissions trading scheme – is in an“existential crisis”. According to theEconomist magazine, its allowancesare now “below the level of junk bonds”.A New York Times editorial crows thatEurope has conceded its leadershiprole on climate.

The “crisis” has been caused specificallyby the European Parliament’s decisionto reject by just 19 votes a proposalto remove temporarily some of theoversupply that has overwhelmedthe market for permits to emit carbondioxide.

Conversely you could argue that thescheme is meeting one of its maingoals. It was launched in 2005 as acap-and-trade system, with the intentionof setting an absolute limit upon thetotal amount of emissions across theEuropean continent emanating frompower stations and from heavy industry.

This is precisely what has beenachieved. It may not have changedattitudes to industrial energy efficiency.Or even the merit order for electricityplant. But at least in one way the EU:ETSis a cause for celebration. After all,when initially conceived at the start ofthe century, few external observersoutside Europe thought that 28 countriescould really co-operate so effectively,to ensure almost total compliancewith inventories and assessments.On the back of it, a whole new breed

of carbon traders emerged.

The traders’ commercial interestsensured that genuine free trade ofallowances across national borderscould, and did, take place. In the initialmonths, trading prices were recordedof around 35 euros per tonne of CO2

emitted. Today the price has fallen to lessthan one-tenth of that figure. Indeed,with the marketplace moribund, tradingdesks are losing staff fast.

What went wrong? The simple answeris: the fault wasn’t with the trade. It waswith the cap. The cap has simply beentoo generous. Up until this year, it wasthe role of each sovereign governmentto decide how many allowances weredistributed to their heavy industry. Some(including the UK) were pretty strict.Other governments were not. Thismatters in a system where an allowancebought in Prague or Rome had thesame worth as one bought in Londonor Stockholm.

Over-supply was already obvious whenthe banking crash took place. Givena decline in demand for heavy industrialactivity, their need to hold quite somany allowances diminished, muchas their requirement for liquidity grew.Many permits changed hands, movingfrom heavy industry to electricitygenerators at ever decreasing prices.

Why did the generators want to ownas many allowances as possible?Because although initially permitswere given away free to participants,increasingly the generators in particularwere being forced to acquire theirsvia auctioning. And allowances haveno expiry date. Once obtained, theycan be held in reserve until needed.

With more and more allowancesflooding into an already over-suppliedmarket, the law of supply and demandled to the exponential price collapse.The motion defeated in the EuropeanParliament had been intended to holdback 900 million allowances for sixyears, in the hope of stabilizing prices.

It did not succeed, because multina-tional heavy industry lobbied againstthe principle of changing the rulesmid-game. For obvious reasons:they prefer lower prices. This voteeffectively reduces the trading system

itself to a minor nuisance, as tradingprices are forecast to stay at or around£2.25 per tonne for the rest of thedecade.

Many free market commentators cel-ebrated. That is certainly not how mostof British industry perceives it. Fewcommentators understand that, fromlast month, it is irrelevant to thosemanufacturing in Britain what theEU:ETS trading price is elsewhere inEurope.

For British manufacturers the effectivetrading price is £16 per tonne this year,increasing each year subsequently.This is because the chancellor hasunilaterally introduced a "floor pricefor carbon", which ensures there is aminimum price paid in Britain, re-gardless of the trading price on thecontinent. The lower that tradedprice, the more the extra differentialbetween the prices paid in Britain andthose elsewhere in Europe. And themore British industry is placed at acompetitive disadvantage.

It is a point that the government wasmaking very plain to all UK MEPs.Practically all Liberal Democrat andLabour MEPs listened. In contrast al-most the entire 25 strong contingentof Conservative MEPs – with fourhonourable exceptions – voted to in-crease the differentials between UKand continental prices, to the UK’sdetriment. Had they voted as thegovernment requested, the proposalsfor backdating would have passed, withthe relative damage to British industryreduced.

The saga may not be over. Later thissummer the European institutions areset to consider alternative options toreinvigorate the trading scheme. Thereis a determination amongst many(although far from all) European gov-ernments to make the scheme work.But it will not be easy.

I fear that some of those rejoicingtook delight in doing down anythingconcerned with helping the environment.Whether they are equally pleased withdeliberately decreasing business op-portunities in Britain, it is nonethelesswhat these ill-informed cheerleadershave achieved. This is no time forcelebration.

EU vote to keep carbon costs lowhurts the environment – & industryThe collapse in prices for carbon permits since the global financial crisis has led many

to question the design of the EU’s Emissions Trading Scheme. According to Andrew Warren, director ofthe Association for the Conservation of Energy, a recent EU vote is set to keep prices low into the future– while disadvantaging industry in countries where higher carbon floor prices have been set.

“Multinationalheavy industrylobbied against theprinciple ofchanging the rulesmid-game.”

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Tighthouse,

New York City

Here's a surprising fact: the first certified passivehouse in New York City was built in 1899. Thisretrofit of a derelict row house surpassed Enerphit,the Passive House Institute's retrofit standard,and boldly aimed for full certification.

Architects Fabrica 718 and passive house en-gineers Zero Energy Design decided to insu-late the walls and roof both externally andinternally to reach the required performance.

"We definitely were convinced by exterior in-sulation and were lucky that the building wasn't

landmarked so we could actually use the ex-terior insulation," says architect Julie TorresMoskovitz. "We actually achieved our airtight-ness with [external insulation] combined withsome critical membranes."

Spray foam insulation was used on the wallsand roof internally. "We used open-cell sprayfoam, which is vapour permeable and will allowdrying to the interior," says Jordan Goldmanof Zero Energy Design.

The green agenda here is about more than justenergy efficiency though: rainwater collection,solar thermal and photovoltaics also feature.The architects say the house – which was certifiedby Irish passive house pioneers Tomás O’Learyand Art McCormack of the Atlantic-straddling

Passive House Academy – needs 90% lessheat than a typical dwelling.

"We have been monitoring the house carefullyfor about 9 months...and making various tweaksalong the way," Julie says. "Once we have 12months of data — covering us through a completeheating and cooling season — we will have alot more specific data on the home's performance.The home is doing very well now though andthe owner is thrilled."

Having designed NYC's first certified passivehouse, Julie Torres is taking the passive housegospel to the world — Princeton ArchitecturalPress has just published her book The GreenestHome: Superinsulated and Passive HouseDesign. �

Virtually any building, anywhere can achieve certified passive house status, as these four transatlanticbuildings show – including a Viennese skyscraper, an upgrade to an NYC home predating the Empire StateBuilding, a German museum housing valuable works of art and a net zero energy home in New Mexico.

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RHW.2 tower, Vienna

Tall buildings tend to be among the worst en-vironmental and energy offenders – but one newViennese project shows that high rise doesn’thave to mean high environmental impact.

Few buildings symbolise the transition from oilage profligacy to environmental responsibilityas well as Vienna’s RHW.2 office tower.

From 1965 to 2009 the site housed the head-quarters of OPEC (The Organisation of Pe-troleum Exporting Companies). That building’snow been replaced with the tallest building inthe world to achieve passive house certification.Perched on the bank of the Danube canal,the glazed facade of RHW.2 rises almost 80metres high. The 21-storey building is hometo 900 employees of the Austrian Raiffeisen-

Holding banking group, and also houses akindergarten and public café.

"This building proves once again that the pas-sive house standard and good architectureare perfectly compatible," says Prof WolfgangFeist, director of the Passive House Institute.

The tower's heating and cooling demand wasreduced by 80% compared to conventionalhigh-rise buildings. A photovoltaic array andgeothermal heat pumps help to meet the build-ing's electricity and heating demand respectively,but the bulk of the building’s energy is suppliedby a biogas-powered combined heat, coolingand power plant. Even waste heat from the datacentre is re-used, with cooling partly comingfrom the Danube canal itself.

Cool water from the canal is circulated via pipesembedded in the building’s concrete frame. Thebuilding also features a twin façade, consist-ing of triple-glazing in the building’s thermal

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envelope sitting inside a glazed façade. In ad-dition to reducing the risk of glare and over-heating, this design gives the building anotheradvantage over typical high rises: windows canbe opened without fear of the wind wreakinghavoc inside.

The building’s green credentials go beyondpassive house certification – RHW.2 scoredclose to a perfect score of 949 out of a possible1000 points in achieving a gold rating under theÖGNB (Austrian Sustainable Building Council)quality label.

In July, the RHW.2 tower's passive house certificatewas presented by Susanne Theumer of thePassive House Institute on the 20th floor ofthe tower, overlooking the old city of Vienna.

The project cements Vienna's status as a passivehouse pioneer, with the city's new residentialEurogate passive house district currently underconstruction and due to be completed next year. �

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VOLKsHouse, Santa Fe,

New Mexico, 2012

Architects MoSA didn't just design a passivehouse, they claim to have built a net-zero-energy home that costs 6.5% less per squarefoot to build than a typical dwelling.

Another building that was certified by the PassiveHouse Academy, the VOLKsHouse also getsan Emerald rating — the highest available —from the National Association of Home Builders.

This timber-frame home boasts 250mm of EPSwall insulation, triple-glazed Optiwin windowsand doors, plus solar thermal panels and pho-tovoltaics. And it smashed the passive houseairtightness standard with a pressure test re-sult of just 0.3 air changes per hour (the re-quirement is 0.6). A layer of structural OSBboards within the timber frame structure pro-vides the airtight layer.

To avoid thermal bridging between the twostructures, the house's garage is set ten inchesaway from the main dwelling.

Energy consumption and bills are now beingmonitored to verify savings. Architect Jonah Stanfordsays on the project website, worldecohouse.com,that one of the key ways to keep passivehouse construction cost down is to focus onsimplicity.

"If you find that the systems are getting com-plicated then stop, and think about how yougot there," he writes.

He also says: "VOLKsHouse sets a baselinefor driving down construction costs, serves asa model for training and educating builders,establishes new standards for affordable hous-ing, and unlocks economic potential for theexpansion of green living and eco-construc-tion. If a passive house uses far less energyand costs less to build, there’s no longer anyreason to build anything else." �

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(above) Streetview of the VOLKsHouse, a net-zero energy home that the architects say costs 6.5% lessper square foot than a similar conventional home and establishes new standards for affordable housing

(below) view of the northeast corner of the house and the slanted living room wall. The second floor roof-deck,located over the living room, allows the residents to enjoy the distant mountain view in absolute privacy.

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Museum of Arts,

Ravensburg

Words: Lenny Antonelli & Stephen Quinn

The world's first certified passive house museumopened in Ravensburg, Germany earlier thisyear. The museum houses the private art col-lection of advertising executive Peter Selinka,who died in 2006, and his wife Gudrun. Theircollection features works of German expres-sionism and the avant-garde COBRA movement.

The external walls are constructed from a cavitywall system: on the outside, 200-year old bricksrecovered from a demolished monastery, andbehind this 240mm of mineral wool insulation,followed inside by concrete blocks.

"The greatest challenge was the small numberof windows," says Florian Lang of Bavarianfirm Herz & Lang, who were responsible forpassive house planning and certification onthe project. Artwork cannot tolerate naturallight and is best displayed under artificial light-ing, but this reduces the building's solar en-ergy gains. However, internal heat gains from

visitors to the museum help to compensate."The passive house principle of keeping theheat inside the building turned out to work ex-tremely well in this context," says Lang.

The building was designed by Stuttgart architectsLederer Ragnarsdóttir Oei and built by constructionfirm Reisch.

Some of the building's components had to bere-thought to meet the passive house stan-dard. Cavity wall brackets with minimal steelcontent were developed to cut thermal bridg-ing across the wall cavity, while the team evencame up with a new Passive House Institutecertified revolving door for the entrance.

Passive House Institute founder Dr WolfgangFeist says this is a typical example of how thelow energy standard can drive innovation.

"The passive house is an innovation engine.In particular small and medium businesseshave always met the challenges head on anddeveloped many new and improved 'made inEurope' products, which have significantly im-proved energy efficiency," he says.

"I very much hope that the museum in Ravensburgbecomes a model for many other projects of

this kind."

Heating and cooling — plus humidification anddehumidification — takes place via a groundsource heat pump paired with a gas absorptionheat pump. Conditions in the exhibition roomsmust be kept very close to 20C and 50% humiditythroughout the year.

"In the end, it turned out that passive house wasthe perfect solution for the high indoor envi-ronmental quality necessary for these valuablepieces of art," says Florian Lang.

For further information please visit: www.passivehouse.ie

Stephen Quinn is a civil engineer with Herz& Lang.

Want to know more?Click here to view additional information on

these projects, including an online gallery

featuring illustrations, photographs, and

project overview panels.

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Back in 2004, a group of green-minded friendstried to buy a disused school and turn it into acommunal home. The project never came tofruition, but it was the starting point for Forgebank,a cohousing development of 41 passive dwellingsin Lancaster. Not only is Forgebank one of theUK's flagship passive house projects, it's a bonafide eco-community.

"One of the things we wanted to do was buildmore sustainable housing," says Jon Sear, oneof the original group of friends. When the timecame to build, he acted as the community'sfull time project manager.

Cohousing is a type of intentional community,where private housing is supplemented bycommunity facilities. Residents live in normalhomes, but have a communal kitchen, diningroom, laundry, offices and outdoor spaces.

If they were to make this community a reality,

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the group would first have to overcome an ob-stacle familiar to many sustainable projects:finance. “There were a few difficulties, for in-stance finding a bank willing to give us a loanwhen we weren't an established developer,”group member Alison Cahn wrote in a 2011article in the Guardian. “Eventually Triodos Bankcame to our rescue.”

But this development finance hinged on thegroup finding a lender willing to offer mortgagesfor individuals within the cohousing structure.Pioneering green mortgage lender the EcologyBuilding Society bought into the group’s vision.

Because each property – and occupant – is anintegral part of the cohousing community, securingsuch finance can be problematic, with lendersput off by the complexities of such a project.

For Ecology – with its years of experience lendingto members of cohousing projects and other

ownership structures that encourage sharedresources and low impact living – this wasn’ta problem. The lender even came with an addedbonus: their C-Change mortage includes a 1%discount off their standard variable rate on allhomes built to the passive house standard.

The original group had more than doubled whenit came time to buy land. Leading green designfirm Eco Arc were appointed as project architects.

"There was a great synchronicity between whatthey wanted to do and what we wanted to do,"says Andrew Yeats, principal architect at Eco Arc.

Andrew had previously spent more than twentyyears as resident architect at the pioneeringFindhorn eco village in Scotland, and had un-dertaken a 3,000 mile bike trip to Scandinaviato study cohousing. His partner Lucy Nelson, theother principal at Eco Arc, had also spent timestudying cohousing in Scandinavia and America.

Eco Arc even moved their offices across England,from York to Cumbria, to be closer to the project.

The firm had produced feasibility studies forvarious sites before the group eventually boughta six acre brownfield site on the steep banks ofthe River Lune near Halton village, three milesfrom Lancaster city.

The group took a risk and bought the site at aknock-down price, without having securedplanning permission.

The plot was part of a larger site once hometo Halton Mill, which manufactured oil cloth andwas built in the 19th century. Major demolition,remediation and site stabilisation work was neededbefore construction could begin. "It was a reallydifficult site to develop," Andrew Yeats says.

Unlike most construction projects, he says thatplanning a cohousing development requiresa participatory, consensus-led design processamong the whole community.

"We did one weekend a month with the first 30householders. We went through everything fromchoosing a site, to site organisation, to pickingthe front doorknobs. We did everything together.I think it went exceptionally well, and that's partlybecause we're reasonably well experienced inthat genre."

By the time preferred contractor Whittle Con-struction was appointed, the initial design hadbeen done. The contractor then met regularlywith the whole design team for 12 months priorto starting on site to thrash out a workable detaildesign.

“These project meetings enabled us to under-stand the philosophy of the client and their designteam to achieve Code for Sustainable HomesLevel 6 and passive house accreditation,” WhittleMD Graham Bath told Green Building magazinein Summer 2012. “Whilst we had carried outvarious schemes for housing associations through-out the Northwest to CSH Level 4, the projectbrought new and exciting challenges, particularlydue to the utilisation of masonry construction,rather than the more usual timber frame orprefabrication solutions.”

The site features 41 homes across seven terraces,ranging from one-bed flats to three-bed houses,including 7 “upside down” three-bed units – wherethe living room is on the first floor and bedroomson the ground floor. Thirty-five of the units arepart of the cohousing community (one terrace isprivate housing outside the community setup).

As part of the design brief, all 41 units had toachieve passive house certification — this wasbecause, Andrew Yeats says, it's a "robust andunquestionable" standard that would verify theenergy efficiency of the homes. "It would beunchallengeable," he says.

Eco Arc came up with eight different possiblewall build-ups, but cavity wall was ultimatelychosen. Not only was it the cheapest option, itwas also the one contractor Whittle Constructionwas most comfortable with.

The inner and outer leaf were both built withEnviroblock, which is produced in the UK byAggregate Industries from recycled and secondaryconcrete aggregates. The 300mm cavity is fully-filled with Knauf Earthwool DriTherm glass woolinsulation – and 300mm Springvale Platinum �

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The winner of the Social/Group Housing award at the 2013 UKPassivhaus Awards, Lancaster Cohousing’s Forgebank developmentin Lancashire is riddled with green features. Not only are all of its41 homes passive house certified – it scores top marks in theUK’s Code for Sustainable Homes too.

Words: Lenny Antonelli & Jeff Colley

Floorshield insulation beneath DPC level, andfeatures thermal bridge free TeploTie basaltwall-ties too. Aerated Celcon thermal blockswere used to reduce thermal bridging at sev-eral key junctions – including sub-floor wallsand from eaves to roof apex, and to form in-nerleaf at end of terrace walls.

Super-wide cavities might seem like a relativelynew phenomenon in the era of energy efficientbuilding, but Eco Arc first used this detail in 1992.

Passive house consultants Alan Clarke andNick Grant were brought in to model and op-timise all thermal details in Therm, going throughmany iterations to optimise cost using PHPPas a design tool, with Clarke providing sitesupport, including ongoing thermal imaging tocatch potential issues during construction.

The south elevations of each terrace are heavilyglazed to maximise solar gain, but becausethe opaque sections here are so small, tim-ber frame was chosen over block. The Kertostructural timber frame system is insulatedbetween the studs and externally with Pa-vatherm Plus woodfibre insulation and cladoutside with Marley Eternit Operal and Cedralcement fibre-boards.

Under the ground floor there's traditional strip

foundations with 250mm of EPS insulation belowthe concrete slab, which contains GGBS, a recy-cled alternative to traditional portland cement.

Upstairs, the roofs of seven of the units areinsulated with 350mm of Knauf Perimeter Plusloose glass wool insulation between the raftersin seven units. To reduce cold-bridging there'sGutex woodfibre board over the rafters, andthe roof insulation zone is continuous with thecavity wall insulation zone to ensure a continuousthermal wrap. This vaulted ceiling approachwas dropped for the remaining 34 houses oncost grounds and replaced with a bob-tailtruss used instead of a vaulted ceiling, and500mm of Knauf Loft Roll insulation laid hor-izontally at ceiling level. Beneath this, no cavityclosers were used, in order to ensure a continuousinsulation layer.

According to Nick Grant, the roof detail, as wellas ground floor and wall details were heavilyinfluenced by the details for Denby Dale1 –the UK’s first cavity wall building to achievepassive house certification – as well as detailsin the AECB’s Gold standards. “The GreenBuilding Store put out a lot of free informationfor people to use,” says Grant.

The wet plaster internally serves as the airtightlayer on block walls, with Pro Clima Intello mem-

branes in the timber frame elements, and ProClima tapes used to seal junctions.

To achieve passive house certification, eachhouse had to individually meet the airtightnessrequirement of 0.6 air changes per hour, andtest results ended up between 0.35 and 0.6air changes per hour.

A wood chip district heating system, fuelledby chips from a local woodland, services thewhole community. The 150kW Herz boiler wasinstalled in an old Halton Mill building, whichprovides a workspace for residents.

The roof of the mill is undergoing insulation andairtightness work. The budget to renovate the millwas limited, so it was decided to undertake a deepretrofit on the roof, where 30% of heat is lost, ratherthan a modest upgrade of the whole building.

But the mill has a high heat load compared to allthe dwellings combined, so the real decision camedown to how the mill was heated.

"We didn't really want to use fossil fuels," AndrewYeats says. "It was kind of an obvious choice really."

The mill has a 40kW solar thermal array too, andthe district heating system is setup to take heatfrom this as a priority before the boiler kicks in.

A network of pre-insulated pipework distributeshot water to each of the dwellings, which havejust one or two Quinn radiators each. A lot ofheat can be lost over a district heating network,but by performing a detailed analysis to workout the hot water demand first the team wasable to specify smaller pipes, which will helpto avoid unnecessary losses.

Most of the dwellings are ventilated by PaulFocus 200 mechanical ventilation systems withheat recovery (MVHR), with the exception ofthe six one-bed flats, which use Zehnder ComfoAir200 MVHR systems instead. “This was due tothe need to achieve a base airflow rate suitablefor single person occupancy which was lowerthan the minimum flow rate of the Focus,” ex-plains M&E consultant Alan Clarke. “It alsohelped with space constraints as the MVHRhad to go in the kitchen and the Zehnder unitfitted inside a single 600mm kitchen unit.”

For electricity generation, substantial solarphotovoltaic arrays – selected for their greenand ethical credentials as well as their efficiency– sit on south-facing roofs, and Forgebank isalso planning to hook up to the nearby 160kWHalton Lune hydropower scheme. This wasessential for reaching Level 6 of the Code forSustainable Homes — the highest rating possible— which the development achieved. Electricityuse at the development is unusually low though,most likely because there are so many sharedfacilities.

A ground floor wall detail reveals the attention to insulation continuity and reduced thermal bridging;(below, left to right) 300mm graphite EPS in base of walls, Teplotie wall ties & Celcon inner leaf beneathDPC; Enviroblock walls with 300mm Knauf Earthwool insulation; (p37, clockwise from top) thesedum roofed common house; a 150kW Herz biomass boiler heats the development via district heating;Celcon blocks installed from eaves to roof apex to reduce cold bridging; south elevations with Kertotimber frame panels.

A decision was taken not to install rainwaterharvesting systems, with water conservationmeasures adopted instead, including rainwa-ter butts, plus low-water taps, showers, bathsand WCs and water efficient white goods.

But apart from energy efficiency and environ-mental stewardship, community is at the coreof Forgebank.

A sedum-roofed common house — built to thesame spec as the homes, but not passive housecertified — provides communal facilities for cook-ing, eating, and socialising.

There's also a pedestrian-only street runningthrough the community, plus a bike store, anew pathway along the river, and a smallwoodland too. The residents have also cometogether to form a food co-op to buy food in bulk.All community decisions are made by consensus.

Tom Lelyveld, who works in energy consulting,only heard about the project in 2011, but foundthe idea exciting and ended up buying a homehere. He and his partner were looking for agood place to raise their young son, and theidea of a pedestrian-only street for kids to playon particularly appealed.

"It was the community aspect, but also I hadbeen on a study trip to study passive house inGermany, and I like it as a concept," he says."It has pretty much exceeded my expectationsin terms of comfort."

He says that he just has to set his thermostatto maintain a constant temperature and leaveit at that.

"They never get super hot, it's more just abouttopping up." On sunny days in winter, the tem-perature inside can reach 22C purely on solar gains.

"It's a lovely place," Tom says of the community."When we had this massive great heat wave,you walk up the river about ten minutes andyou've got a great swimming spot."

The first residents moved in last August, andthe last of the homes were in the process ofbeing handed over at the time of writing. All unitshave been sold.

Nonetheless certain lessons have been learned:for one, Andrew Yeats thinks there should bea minimum of two airtightness champions onbig projects, and that more attention must bepaid to communicating the importance of air-tightness down to every tradesmen on site, toensure sealing work isn't rushed, or done duringdamp periods, just to expedite the build schedule.

A Building Use Studies survey revealed a fewconcerns among residents that need to beaddressed, but overall the responses wereexcellent, and interviewees cited the warmthand comfort of the homes, the views over theriver, and being closer to neighbours as thebest aspects of living at Forgebank.

Fairly extensive monitoring has been carriedout since construction too.

A coheating test on one dwelling revealed a

measured heat loss of 47.1 W/K, compared tothe 39.6 W/K predicted in Sap. Relative humiditywas initially high after construction, but levelledoff at a normal value of around 40%. Wintertemperatures inside are a steady 19-20C.

"They're not overheating in summer, and they'renice and warm in winter," Jon Sear says.

And for the residents comfort, ultimately, is themost important thing.

SELECTED PROJECT DETAILSClient: Lancaster CohousingArchitect: Eco ArcContractor: D Whittle ConstructionPassive house consultancy & building servicesengineers: Alan Clarke & Nick GrantQuantity Surveyor & Project Manager:Turner & HolmanProject finance/mortgages:Triodos/Ecology Building SocietyPassive house certification: Warm Civil & structural engineering:Gifford (since acquired by Ramboll)Landscape design:Camlin Lonsdale Landscape ArchitectsCode for Sustainable Homes assessor: Eric ParksAirtightness: Paul JenningsMechanical contractor: Rogerson Homeserve +Electrical contractor:R Thomson Electrical ContractorsGroundworks contractor: William PyeRoofing contractor: Pears Roofing

Insulation contractor: A&M Energy SolutionsSedum roof contractor: Green Roofs NaturallyDistrict heating design: Pettit SingletonDistrict heating contractor: James MercerSolar thermal installers: Campbell StewartMasonry (Enviroblock): Aggregate IndustriesKerto timber frame panels: MetsawoodWood fibre insulations: NBT & Ecological Building SystemsWall ties: AnconThermal blocks: H&H CelconAirtightness products: Ecological Building SystemsDamp proof membrane & radon barriers:VisqueenGlass wool insulation: KnaufBelow DPC cavity insulation: Springvale EPS LtdGround floor insulation: JabliteWindows: Green StepsRoof lights: FakroRoof tiles: SandtoftCement fibreboard: Marley EternitGGBS: Tarmac TopmixPaving: Hanson FormpavePainting & decoration: SMLMVHR systems & low water fittings:The Green Building StoreMVHR systems for 1 bed flats: ZehnderMVHR ductwork, grilles & terminals: LindabPV supplier: The Better Roofing CompanyWood chip boiler & fuel feed system:Barden EnergyDistrict heating pipework: RehauHot water cylinders: Mcdonald EngineersSolar thermal array: AO SmithSolar cylinder: AkvatermHeat metres: KamstrupRegulating valves: DanfossRadiators: Quinn Radiators UKKitchens: Howdens JoineryLow water fittings: HansgroheUtility services: Quartzelec

1A free technical briefing on Denby Dale is available at http://bit.ly/SwNimJ





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“The houses aren’t overheatingin summer, and they're nice andwarm in winter"

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PROJECT OVERVIEW:

Development type: 41 certified passive dwellings across seven terraces, ranging from two to ten units per terrace, and associated common house.

Location: Halton, Lancaster

Completion date: 2012

Budget: £5.7m inclusive of 41 dwellings, community buildings and site works. £1,825 per square metre inclusive of extensive demolition, remediation andsite stabilisation works. £1,505 per square metre exclusive of these costs.

Passive house certification: All 41 residential units certified. Common house not certified.

Space heating demand (PHPP): 12kWh/m2/yr (average over all dwellings)Space heating demand (measured): 13kWh/m2/yr (average over all dwellings)

Heating load (PHPP): 9W/m2 (average over all dwellings, no cooling)

Primary energy demand (PHPP): 81kWh/m2/yr (average over all dwellings)Primary energy demand (measured): 77 kWh/m2/yr (average over all dwellings)

Code for Sustainable Homes: Level 6

Airtightness (at 50 Pascals): ranging from 0.35 to 0.6 ACH

Energy performance certificates (EPC): pending

Thermal bridging: Ancon TeploTie low thermal conductivity wall ties, H+H Celcon aerated thermal blocks in all perimeter and party walls at sub floor andabove ceiling levels (from eaves to roof apex) & to form inner leaf (with 1200mm width x 200mm thick Kingspan Kooltherm insulation at steel windpost) inend of terrace walls.

Ground floor: traditional strip foundations. Timber flooring finish, on 150mm RC30 GGBS Concrete slab, 500 gauge Visqueen EcoMembrane recycled slipsheet, 250mm Jablite 70 floor grade under-slab EPS insulation, 1200 gauge Visqueen EcoMembrane DPM (in terraces D & E) or Visqueen radon membrane(terraces A, B, C and F) or a separate radon membrane in terrace G, on sand binding & hardcore. U-value: 0.14

Intermediate floors: 22mm thick T&G floorboards, 253mm deep steel web floor joists containing 100mm MVHR ductwork & drainage ductwork; 200mmsound insulation; plasterboard ceiling finish.

Cavity walls: 8-10mm Wetherby external render system, 100mm Masterblock Enviroblock EV11 100% recycled aggregate concrete block forming both theinner and outer leaf, with three to six courses of blue engineering brick used below DPC at outer leaf. 300mm cavity in-between with Type 2 TeploTie reinforcedbasalt fibre wall ties and 300mm full-fill Knauf Dritherm recycled glass wool insulation. U-value: 0.12. 300mm Springvale Platinum Floorshield insulation belowDPC at perimeter to act as formwork when casting slab.

Timber frame infill sections: 9mm Marley Eternit Operal board, on battens, on ProClima Solitex breather membrane, on 100mm NBT Pavatherm woodfibre insulation board with joints sealed with NBT Pavatape, on 9mm OSB fixed to 300mm Kerto structural sub frames filled with Knauf Dritherm 37 insulation,on 9mm OSB and Pro Clima Intello vapour control layer, on battens for service cavity, finished inside with 12.5mm plasterboard. U-value: 0.12

Trussed roofs: Sandtoft Cassius clay tiles on battens and counter-battens, Pro Clima Solitex Plus Breather membrane, bob tail truss, 500mm of Knauf LoftRoll recycled glass wool insulation, 18mm OSB taped with Tescon No 1, 25 x 50 battens, 12.5mm plasterboard. U-value 0.1

Cathedral roofs: Sandtoft Cassius clay tiles on battens and counter-battens, Pro Clima Solitex Plus Breather membrane, 22mm Gutex Multiplex Top woodfibreboard, 350mm rafters with Knauf Perimeter Plus loose blown glass wool insulation, on 9mm OSB, on Pro Clima Intello vapour control layer, on 25 x 50 battens,on 12.5mm plasterboard. U-value: 0.1

Common house sedum roof: Green Roofs Naturally’s sedum roof system – comprising sedum sprout mix, extensive soil substrate, Nutrifoam mat andwater/roof proof membrane – on 18mm thick WBP ply deck, 50mm treated SW battens, Pro Clima Solitex Plus breather membrane, 18mm thick OSB sarkingboard, 400mm deep JJI roof rafters insulated with Knauf Perimeter Plus, 12mm OSB, Pro Clima Intello VCL, 50x25mm battens to form services void,12.5mm thick plasterboard & skim. U-value: 0.1

Windows: Green Steps alu-clad triple-glazed windows with low e coatings, argon fill and insulated Thermix spacers. Overall U-value: 0.9

Roof lights: triple-glazed Fakro FTT-U5 Thermo roof lights installed in three one-bed flats. Centre pane U-value: 0.5

Heating: up to 93% efficient 150kW Herz wood chip boiler – with modulation from 37 to 151 kW – and 40kW of solar thermal energy – comprising two x 14panel AO Smith flat plate arrays with drainback function, with a Resol Deltasol BS/4 controller and Akvaterm solar accumulator tank - distributing heat viaa district heating network of pre-insulated Rehau pipework.

Microgeneration: 4 solar photovoltaic arrays giving a total of 48 kWp. REC 245w panels on Schletter mounting system with SMA Tripower inverters.

Ventilation: separate Paul Focus 200 MVHR systems in all 35 houses. Passive House Institute certified heat recovery rate of 91%. Separate Zehnder ComfoAir200 MVHR systems in all 6 flats, with Passive House Institute certified heat recovery rate of 92%.

Paving: Hanson Formpave Ecogranite paving range used throughout, featuring 77% recycle materials – including Combined Royal Deeside Victoria at terracesA-F and Aquasett Pennant permeable paving at Terrace G.

Water conservation: ES4 four litre siphon WCs with leak free flushing technology.

Green materials: Masonry block made from recycled concrete aggregates, GGBS cement, wood fibre insulations products, recycled glass wool insulation.

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When it was built in 2009, Canolfan Hyddgenin Machynlleth became the first certified non-domestic passive house in the UK. Four yearson it's still picking up accolades, winning a UKPassivhaus Award this year.

The building's sustainability agenda goes waybeyond energy efficiency to encompass materials,water, biodiversity and more. It has a BREEAMexcellent rating, the highest available at the time.

Built for Powys County Council, the centre housesIT for a neighbouring school, facilities for adultlearners, meeting rooms and a drop-in centre

and council service point.

Leading passive house architect John Williamson,also based in Machynlleth, designed the building,while local firm C Sneade acted as contractor.Williamson was also responsible for the UK'sfirst certified residential passive house, Y Foel,also in Wales.

Tried & tested

So how has the building performed since it wasconstructed?

"We feel the heat loss is fairly close to what we

PIONEERINGPASSIVE OFFICEsurpasses expectations

When it comes to actual energy usage, modern buildings rarelyperform as expected, with many notionally low energy buildingsfalling disappointingly short. As discussion continues about how to solvethe performance gap, one pioneering Welsh passive building has adifferent kind of performance gap – it’s using 40% less energy thananticipated.

Words: Lenny Antonelli

predicted," Williamson says. In fact measuredspace heating demand (14.8kWh/m2/yr) is almostexactly what was projected (15kWh/m2/yr).

Winter temperatures inside vary between acomfortable 20 and 22C, depending on howthe thermostatic radiator valves (TRVs) are set.

Perhaps surprisingly, the building's primaryenergy demand (80kWh/m2/yr) is almost half

that projected (144 kWh/m2/yr), mainly becausecomputer use has been lower than expected.

Those familiar with the passive house standardknow that even the latter figure is above the120kWh/m2/yr demanded for certification. Butbecause Canolfan Hyddgen houses electric-ity-hungry servers for other buildings, and be-cause the team did everything possible to cutpower use, the Passive House Institute stillcertified it.

The energy used to heat the building has dropped40% since it was built, as occupants get to gripswith how it functions — and learn, for example,that in a passive building radiators needn't beon if a room with lots of computers is full withpeople.

Now the boiler is only used briefly on cold morn-ings. And close monitoring has enabled theteam to adjust timer controls and settings tocut energy use even further. Monitoring of aclassroom full with 22 adults showed carbondioxide, humidity and indoor temperature allwithin normal levels.

Simple heating design

A small gas boiler provides space heating atCanolfan Hyddgen. "We didn't want to com-plicate the project with extravagant renewablesystems," Williamson says. The boiler was thesmallest the team could find, but at 9-22kWhe reckons it's still too big.

"I've never seen so little plant in a building ofthis size," says building manager Edward Cain.If it's needed, the boiler delivers heat to lowsurface temperature radiators in the main teach-ing rooms and a few of the public spaces.

Heating controls are designed to be simple,robust and easily adaptable. "Boiling somethingcomplicated down into something simple isthe challenge," Williamson says.

Radiators at Canolfan Hyddgen are equippedwith TRVs to give occupants control. But theboiler also kicks in automatically if the indoortemperature drops below a set level.

The only hot water demand is from sinks, sopoint-of-use electrical heaters were chosenfor water heating. But with minimal pipe runs,low flow spray taps and timer switches, wateruse is designed to be low.

"If you minimise the amount of water you needin the first place, then you don't need all thiscomplicated kit behind it to provide the water,"Williamson says.

Lighting, cooling and ventilation

Office and meeting rooms sit around the perimeterof the building to benefit from sunlight, with IT

teaching spaces at the core. But a corridorand breakout spaces separate these areasfrom the glazed facade to protect occupants fromglare and overheating. Brise soleils on the southfacade, coupled with the asymmetrical pitcheddesign of the roof, helps control these issues too.

Meanwhile, the building's masonry core providesthermal mass that helps to smooth internaltemperatures by absorbing heat and releasingit slowly.

The ground floor slab contains 60% HansonRegen GGBS (ground granulated blastfurnaceslag), a low carbon alternative to portland cementthat's made from a by-product of iron manufacturing.

Meanwhile the internal walls are constructedfrom Enviroblock, which is produced from secondaryand recycled concrete aggregates. Made in theUK by Aggregate Industries, the blocks aresuitable for use above or below the damp proofcourse, internally or externally. Enviroblockhas been awarded the BRE's 'ResponsibleSourcing' certificate, which is given to productsthat demonstrate environmental and socialresponsibility.

On summer nights, the building's ventilationsystem purges heat from the masonry elementsto cool the building for the next morning.

The building is naturally ventilated during theday in summer, with the MVHR set to summerbypass mode to maintain extract requirementsfrom toilets, and cooling the building at nightif needed. “The natural ventilation strategy insummer has worked well to reduce operationalenergy use,” says Williamson, “particularlynow the occupants are confident in its use.”

Williamson considered ventilating the buildingnaturally with automated windows, but saysthis would have been ineffective on windlessdays, and expensive. So instead the buildingis ventilated by five Drexel & Weiss heat re-covery ventilation units - comprising three de-centralised and two centralised units. “They’renot certified yet, but they’ve been used successfullyin many certified passive house schools andoffices,” says Williamson.

Timber frame envelope

While the core of the building is masonry, thethermal envelope is constructed from timberframe that sits on a thermal block -built plinth,together with an I-beam cassette roof. Thetimber frame elements are insulated with Warmcelcellulose, which is made from recycled news-paper made in Wales, installed by Powys-basedfirm Pen Y Coed.

Williamson says he particularly likes Warmcelfor its hygroscopic buffering and excellentdecrement delay attributes. �

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The south-facing roof slope features a 7kWphotovoltaic array, supplied by Dulas, thatproduces 25% of the building's electricity. Thenorth slope features a biodiverse roof sownwith local wildflowers, designed in conjunctionwith local wildlife groups.

Williamson says the sedum roof offers excel-lent decrement delay too. "It really helps withkeeping the building cool," he says.

The dilapidated 1850s building that previouslyoccupied the site was demolished, but its roofslates & cills were incorporated into CanolfanHyddgen's roof, while the old building's wallswere crushed and used in the construction ofnew drainage systems and hard landscaping.

Canolfan Hyddgen also smashed the passivehouse airtightness standard of 0.6 air changesper hour with a score of 0.25. The thermal enve-

lope was made airtight using Pro Clima IntelloPlus 'intelligent' vapour checks in conjunctionwith Pro Clima tapes and glues, all suppliedby Irish company Ecological Building Systems.

But despite the runaway success of the project —it was the first building in the world to achievepassive house and BREEAM certification si-multaneously — Williamson says some lessonswere learned. �

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(above) The building features a pitched roof with a solar PV array on the south-facing slope and a sedum roof, sown with local wildflowers, on the north slope;(below) 300mm of Jablite insulates the groundfloor; (inset) airtightness and insulation around the MVHR ductwork; (p45) the building is clad in locallysourced European larch (top); its structure combines timber frame external walls and Enviroblock internal walls on a GGBS slab.

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For one, establishing a building's IT strategyat the outset is crucial. Late in the design phasePowys County Council appended a server roomto the plans, which added 720 watts of heat.This demanded some late design tweaks toprevent overheating, such as adding a secondbrise soleil above the ground floor on the southfaçade and redesigning summer extraction ductsto the server room.

Williamson says another important lesson isthat local authorities are often locked into frame-work agreements with technology suppliers,meaning they can't always switch to new energyefficiency technology or supply chains easily.

The cost of the build ended up at £1,537 per squaremetre — not including the PV, biodiverse roof andcanopy — and £1,784 when these are included.

But the proof of the building's success is comfort:Williamson says that during recent cold winters,staff at Canolfan Hyddgen "couldn't wait to getinto work".

Though the building is four years old it onlyentered the UK Passivhaus Awards this year,as real-world monitoring data is required for entry.And it emerged victorious in the non-domes-tic category, beating strong competition fromboth the Green Base community centre onMerseyside and the new offices of constructionfirm Interserve, two other flagship passive houseprojects. The project had previously won a WelshLocal Government Association sustainability

award, and a CIBSE new build of the year prize.

Speaking at this year's Passivhaus Awards,Williamson praised the Passivhaus Trust forcreating awards that recognised both energyefficiency and aesthetics.

He said: "We hope such successful examplesof passive house will inspire others to adoptand engage with this proven approach to lowenergy buildings.”

SELECTED PROJECT DETAILSClient: Powys County CouncilArchitect & consultants: JPW ConstructionContractor: C SneadePassive house certifier: Passive House InstituteCivil & structural engineering:Bob Johnson Consulting Structural EngineersElectrical contractor: EOM Electrical contractorsAirtightness testing & consultancy: Airtight NoisecheckCellulose insulation:Warmcel, installed by Pen Y CoedFloor insulation: JabliteSheathing board: HuntonCladding: Powys Castle EstatesPlasterboard & plaster: British GypsumMasonry: Enviroblock (Aggregate Industries)Airtightness products: Ecological Building SystemsWindows and doors: InternormScreeds & GGBS: HansonVentilation: Drexel & WeissLow water fittings: Green Building StoreGreen roof: ICBSolar PV: DulasSolar PV inverter: FroniusCondending boiler: Remeha






new build

PROJECT OVERVIEW:

Building type: Local authority offices andlearning centre

Location: Machynlleth, Powys, Wales

Completion date: November 2008

Budget:£1.2 million. Funded by Welsh Assemblyand Powys County Council.

Space heating demand (PHPP): 15 kWh/m2/yr

Space heating demand (measured, average

over 4 years): 9 kWh/m2/yr

Heat load (PHPP): 4.8kW

Primary energy demand (PHPP):144 kWh/m2/yr

Primary energy demand (measured, average

over 4 years): 50 kWh/m2/yr

Carbon emissions (PHPP): 84. kg CO2 m2/yr

Carbon emissions (measured): 48.4 kgCO2 m2/yr

BREAM Offices: Excellent (84.43%)

Airtightness (at 50 Pascals): 0.249 ACH

Ground floor: Slate finish with 150mm RegenGGBS slab under this, followed underneath by300mm Jablite 70 EPS insulation. U-value: 0.122

Walls: European larch cladding counterbattenedto 22mm Bitroc sheathing board externally,followed inside by 195mm stud insulated withWarmcel, 9mm OSB, 50mm service cavity,25m Gypsum plasterboard, Gypsum Plas-ter skim finish. U-value: 0.18

South roof: build up features 300mm ofWarmcel with 50mm uninsulated servicecavity inside this, and finished internally with13mm Gypsum plasterboard and GypsumPlaster skim finish. U-value: 0.125

Windows: thermally broken triple-glazed In-ternorm Edition windows with Krypton filling.U-value: 0.78

Heating system: Heating system: 24-9kWBroag Remeha low NOX condensing gasboiler, providing 4054 kWh/yr (PHPP)

Ventilation: five Drexel & Weiss AerosilentBusiness units, with 85% heat recovery ac-cording to VDI 2071

Electricity: 7kW solar photovoltaic array withFronius inverter. Producing 19.38 kWh/m2/yr.Projected to produce 5250kWh/yr but mon-itoring found it producing 6493 kWh/yr in 1styear due to cold bright sunny winter weather.Average dropped back over four years whentwo milder overcast winters and a very wetsummer were included.

Green materials: recycled concrete blocks,cellulose insulation, timber frame elements,GGBS

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Vernacular passiveA building doesn’t have to be designed as a cube to meet the passive house standard, but it helps. Thisas yet uncertified passive house in Carlow shows that, climate permitting, less compact designs can bemade passive – by pushing the envelope.


Most passive buildings are compact, south-facing and simply-shaped. Starting from thesefirst principles maximises solar energy gainsand reduces heat loss — a big leg up for anyproject trying to meet the passive house standard.

But this house in County Carlow threw therulebook in the bin, and instead adopted theaesthetic of a traditional Irish farmstead: acluster of buildings around a central farmyard— not necessarily the ideal layout for savingenergy.

But it proves that achieving the passive housestandard needn't mean building a boring box, par-ticularly in the mild climate of south-east Ireland.

Passive House Plus's predecessor magazine,

Construct Ireland, first published a short profileof the project in 2011, when construction wasnearing completion.

Since the house was finished, it has become oneof Ireland's flagship passive house projects —not just for its energy efficiency, but also itsthoughtful vernacular design. It was one ofthe finalists at this year's Isover Ireland EnergyEfficiency Awards, and won in the residentialsection of the Saint-Gobain awards last year.

But homeowner Tony Holden says he didn't builda passive house for environmental reasons— that was just an added bonus.

"The main reason I'm building a passive houseis that it's a quality control stick. It's a standard I

can test. I've got good metrics to ensure my houseis as it's supposed to be," he told us back in2011. He's been living in the house about 18months now — so how was it performing?

"I'm very happy with the house," he says. "I'mvery relaxed in the house and delighted [the build]is all over."

There was some overheating this summer, buthe acknowledges temperatures rose unusuallyhigh this year.

Plus, he was keen to have a generous amountof glazing on the south and west facades, andknew overheating could become an issue fromthe design stage.

"I wouldn't say it's uncomfortable, we've kindof got used to it at this stage," he says.

One particular overheating issue occurs onthe west-facing wing in summer.

"While we did put a brise soleil to the west itis never very effective, as the sun is settingand is therefore very low on the horizon," saysproject architect Cathal O'Leary of OLS. He saysinternal blinds will probably be necessary tohelp control any overheating here.

But Cathal says he's not generally a fan ofusing internal blinds to control overheating —it often means closing off views on the sunniestdays of the year. Generally, he thinks getting thebalance of glazing right, and designing in externalshading is the answer.

Tony's now investigating whether it’s feasibleto re-engineer his 8kW Danfoss ground sourceheat pump, which draws heat from a 110mborehole, to provide cooling in summer.

Heating in the house is distributed by wall-basedVariotherm panels — essentially pipes encasedin Fermacell board — and Tony wants to workout whether circulating water through the panelsat 10-15C can provide adequate cooling."I can'tgo too cold or I'll have condensation on all thewalls," he says.

He had originally planned to install a wood pelletstove, solar thermal system, plus heating elementsin the heat recovery ventilation. But he saysthat plan grew too elaborate and expensive,so he scrapped it and put in one ground sourceheat pump for space and water heating. DamienMullins of Heat Doc, who designed the system,says in practice at Tony's house the heat pumphas a COP of about six for space heating, andseasonal performance factor of around 460.

"If you were to run it in any low energy buildinglike the Holdens’ house, then your seasonalperformance factor will be higher becauseyour input temperature from your bore holesis high and your output temperature is low.The SPF for space heating in this case mightbe 6 or 7," Damien says.

Heat pumps work most efficiently when they’regradually feeding low temperature heat into athermal store – typically the floor itself, via un-derfloor heating pipes. But the Variotherm wallpanels aren’t intended to provide a thermalstore – instead they offer quick response, evenwith low temperature heat. Heat Doc’s solutionwas to install a 400 litre buffer tank so that inaddition to the hot water cylinder, the heat pump canoperate consistently at optimal efficiency, �

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topping up a reservoir of hot water so that it’sthere when needed.

The house has a room-sealed, airtight solid fuelstove too.

Hitting the passive house standard was important,but it wasn't Tony's first priority – design camefirst.

The finished house breathes new life into theword 'vernacular', a term often used to describedull, uninspired bungalows. But this genuinelyrecalls an old Irish farmhouse, with its white walls,slate roof and clustered, almost organic layout.

"The thing that I really liked about Tony andSiobhán is that when we met them, they saidthey wanted a house that fitted in the land-scape," says architect Cathal O'Leary. "Wedesigned it first and then tried to make it passiveafter, if we could within the budget."

The house is divided into three 'blocks', centeredon a courtyard. The bedroom wing lies to theeast to catch the morning sun, the kitchen andliving areas face south, while a more formalentertaining room occupies the west wing. Theyard is then enclosed by a separate work-shop/garage to the north.

Of course this kind of design doesn't usuallylend itself to energy efficiency, though architectCathal O'Leary says the volume to surface arearatio in this case is surprisingly good at 0.79.

But to be sure of hitting the passive house stan-dard, the team had to compensate by design-ing an ever more efficient thermal envelope.

"We had to exceed the passive standard becausewe didn't build a compact form house," Tony says."The airtightness had to be a lot better than theminimum requirement."

This meant a daunting target of 0.3 air changesper hour (which was achieved), rather than theusual 0.6, and the building’s walls, roofs andfloors are heavily insulated even by passive housestandards, with all U-values below 0.1.

Even then, considering the layout, Cathal O'Learysays the same house built in central Europewouldn't hit the passive house standard.

Before the build Tony went out to tender forcavity wall, single leaf block and timber frameconstruction, but cavity wall came in cheapest.

The build-up features 100mm Cemex blockexternally, 150mm Quinn-Lite Aircrete block in-ternally, and a 300mm cavity in between that'sfilled with Korefill bonded beat insulation. Insidethe inner leaf, there's a further 75mm insulatedservice cavity.

"We had to exceed the passive standardbecause we didn't build a compact formhouse. The airtightness had to be a lotbetter than the minimum requirement."

For airtightness, there's a Gypsum Airtite Quietparge coat on the inner block leaf, plus a vapourmembrane in the service cavity build-up.

Cathal O'Leary says the extra-thick build-up addsto the vernacular feel of the house, evoking thebulky walls and deep reveals of old Irish housesbuilt from random rubble or mud.

Upstairs, the roof is insulated with Climowool KF2glass fibre, while airtightness here is providedby an Isover Vario vapour barrier.

The ground floor features a Viking HousePassive Slab foundation system, which includes400mm of EPS Kore insulation. The windowsare Pazen Premium Maximum triple-glazed

Eucalyptus units with aluminium cladding ex-ternally.

While Tony and his wife Siobhán have been livingin the house for nearly 18 months, landscapingwork has just begun, and Tony says that becauseof this, the house doesn't recede into the land-scape as much as he'd like just yet. �

new build

(opposite) The masonry building’s cavity walls feature TeploTie basalt wall ties and an inner leaf of QuinnLite low thermal conductivity blocks; (This page, above) Light shining into the dining area in the west-facingwing of the house. This can be a cause of overheating in the summer as the setting sun is too low in thehorizon for the brise soleil to be very effective; airtightness measures include the Isover Vario vapourbarrier (below left) and Gypsum Airtite Quiet parge coat (middle); while the Optima system’s thermallybroken steel structure addresses thermal bridging.

ph+ 49

"The colours are quite stark at the momentuntil we get the landscaping done," he says.He also plans to do some planting on the wallof the garage, and the gable ends of the house,to help blend it in further.

OLS have yet to submit the house for passivehouse certification, but plan to later this year.

Tony reckons that because the less-than-optimum layout required the house to go theextra mile in terms of thermal performance, itwasn't the most economical build.

He's not sure if the extra cost of reaching thepassive house standard, considering the de-sign, was justified.

"I'm very happy with the house and a lot of thecost is probably associated with the designrather than the fact that it's passive," he says.

But he says hitting the passive house standardverifies the house is well built.

"It's a real measure of the quality of a build."

SELECTED PROJECT DETAILSClient: Tony & Siobhán HoldenArchitect: OLS Architects Civil / structural engineer: Peter Bolger ConsultingMain contractor:American Timber Framed Houses Ltd (liquidated)

Mechanical contractor: Heat DocAirtightness tester: Integrated Energy Indicative BER: 2eva.ieAirtightness, roof insulation & internal insulationsystem: IsoverPlasterboards & plaster: Gyproc Wall & floor insulation: Kore InsulationRoof insulation: The Insulation StoreExternal render: Weber Thermal blocks: Quinn LiteDense concrete blocks: CemexThermally broken cavity wall ties: AnconInsulation for window reveals: KingspanWindows and doors: Pazen Ireland Radon barrier: TradecraftOSB: SmartplyRoof trusses: DTEZinc roof: VMZINCRoof tiles: CapcoHeat pump: Heat Pumps IrelandMVHR: Pure Renewable EnergyBore hole: Wall's Well DrillingFlooring: AML Architectural ProductsLighting: Willie Duggan Lighting






new build

PROJECT OVERVIEW:

Building type: 295 sq m detached steppedsingle-storey house, with a wine cellar attachedand a workshop detached.

Location: Tullow, Co Carlow

Completion date: September 2011

Passive house certification: pre-submission

Space heating demand (PHPP): 15 kWh/m2/yr

Heat load (PHPP): 10 W/m2

Airtightness: 0.3 ACH

Indicative BER: A2 (46.26 kWh/m2/yr)

Ground floor: Viking insulated concrete raftfoundation, insulated with 400mm of EPSKore insulation with Rhinoplast Ultra Radonbarrier. U-value: 0.8

Walls: 15mm Weber render to 100mm Cemexdense block external leaf, 300mm cavity filledwith Korefill bonded bead insulation with Anconbasalt Teplotie wall ties, 150mm Quinn-LiteAircrete block to inner leaf, with Gypsum AirtiteQuiet parge coat, and Isover Optima internalinsulation system to provide 75mm insulatedservice cavity including Isover Metac insulation,thermally broken steel structure, Vario vapourbarrier/airtight system, 12.5mm Gyproc plas-terboard with skim finish. U-value: 0.09

Pitched roofs: Capco fibre cement slatesexternally on treated timber battens/counterbattens, followed underneath by breathableroofing underlay, to DTE timber roof truss, with500mm Climowool KF2 glass fibre insulationbetween joists, Vario vapour barrier, 18mmtaped & sealed Smartply OSB, 150mm uninsu-lated service cavity, 12.5mm Gyproc plaster-board ceiling with skim finish. U-value: 0.08

Flat roofs: VMZinc Plus Quartz zinc standingseam externally, followed underneath by breath-able roofing underlay, on WBP plywood sup-port, on treated timber fillet battens to createfall and ventilation, on 250mm treated timberjoists/counter joists in-filled with ClimowoolKF2 glass fibre followed underneath by Variovapour barrier, 18mm taped & sealed SmartplyOSB, 150mm uninsulated service cavity, 12.5mmGyproc plasterboard ceiling. U-value: 0.08

Windows: Pazen Premium Maxi triple-glazedaluminium-clad eucalyptus hardwood windows,with argon filling and an overall U-value of 0.77.Kingspan phenolic insulation used to preventcold bridging at window reveals.

Heating: an 8kW Danfoss DHP Opti Pro groundsource heat pump with a closed loop collectorin a 110 metre vertical bore hole. The tested COPis 4.34/4.88 under different test conditions, butmore likely circa 6.0 here due to the low Delta Trequired in such an efficient house. The heat pumpfeeds a three hundred litre hot water cylinder.

Ventilation: Paul Novus 300 heat recoveryventilation system — Passive House Institutecertified to have heat recovery rate of 93%,and an electrical efficiency of 0.24

Green materials: Pazen Eucalyptus hardwoodwindows, Isover recycled glass mineral woolroof insulation, reclaimed oak timber plank flooring,Tretford eco backed carpet, all roof timbersfrom PEFC certified sources.

The neatly configured plant room (above) includes a Paul Novus 300 MVHR system and 8kW Danfoss PHP OptiPro heat pump; (below) window reveals insulated with phenolic insulation to reduce cold bridging; a plywood boxused for ease and accuracy of window positioning; Gyproc plasterboard and the Vario airtight system.

ph+ 51

The winner of the Green Building Award at the2013 Green Awards, the new Television MobilesLtd (TVM) HQ in Bartlemy Co Cork is a highlyambitious project. It succeeds in bringing lowenergy design principles to bear on a workspacethat serves a diverse range of functions.

The building provides 1,250 sq m of interconnectedoffices, meeting rooms, an editing studio, canteenand engineering workshop for the television broad-cast and production specialists, TVM. The com-pany, which was established by Bart and HelenArnold in 1986, provides outside broadcastingfacilities to a range of media organisations.

Bart Arnold explains that the company had out-grown its old premises across the road from thenew site long before the first sod was turned onthe project. Four distinct but interconnected spaceswere required. The open plan offices are housed

in a cottage and in a new two-storey buildingconnected to the cottage via the architecturalcentrepiece of the project – a 2.5 storey cylindricaldrum finished in American cedar. To the rear ofthis space, a large industrial warehouse wasdesigned to accommodate the articulated ve-hicles and related workshops that deliver thecompany’s outside broadcast services.

“When it came time to build,” Bart says, “we said,ok, we’re probably only going to do this onceever in our lives so let’s try and build somethingfirst of all that is not an industrial building, some-thing that has architectural value and, as part ofour drive to try and be as ecologically friendly aspossible in what we do, we decided to explore theoptions and see if we could build an industrialoffice building to passive house standards.”

While the project isn’t a certified passive house,

it does show some of the characteristics of apassive house. Impressive U-values for theopaque elements all sit within the sort ofrange that’s typical of certified passive build-ings – in this case between 0.104 and 0.15 –and a mid-construction blower door test resultof 0.52 ACH indicates that the building may bethere or thereabouts in terms of airtightness.

The building features triple-glazed doors andwindows. Described by manufacturer VikingWindow AS as “windows for passive houses”,the windows – which offer centre pane U-valuesof 0.6 – are not included in the Passive HouseInstitute’s certified component database.

Michael Regan of E-Project Chartered Architectssays that one of the central challenges of theproject was to create a headquarters that wouldmeet all the functional requirements of a highly

Media HQ

shows ultralow energy visionWhile Ireland’s minimum energy performance regulations for dwellings have come on leaps and bounds inrecent years, standards for non-domestic buildings have remained untouched. Which makes forward-thinkingmedia production company TVM’s new ultra low energy HQ all the more impressive.

Words: John Hearne & Jeff Colley

sophisticated business, while also sitting comfortablyinto a rural village environment. The finishedbuildings would face the school and churchdirectly across the road.

“The client was quite keen that the designwouldn’t be shouting at the rest of the village,”says Michael. “For that reason the incorporationof the cottage element as part of the schememaintained the established village scale of thedevelopment along the road frontage. Then asyou progress back through the site, the buildingbecomes much more innovative in terms of itsdesign, and then purely functional for the work-shop at the back.”

If marrying these conflicting imperatives wasn’tchallenging enough, the client’s insistence onhigh standards of sustainability raised the bareven higher.

Planning permission had been granted by thetime Michael Regan joined the E-Project practice.However, much of the detail within the planningapproved scheme changed substantially asthe architects and the full design team workedthrough the details and more research andtechnical calculations were established duringthe detail design stage.

“For planning purposes, there were a lot of greenagenda items included, but a lot of these fellby the wayside, not for cost reasons, but becausethey were found to be impractical,” Michael says.“For example, at planning stage, the work-shop building had a south facing solar wall.We found however that so much hot water wouldbe generated that it couldn’t be used. You’d justbe dumping it.” A smaller solar array has beenincluded to suit the actual hot water requirementsof the building in use.

In addition, the south facing roof of the workshopwas fitted with 217 sq m array of 130 photovoltaicpanels from PV Tech – the largest of its kind inIreland. The system comprises a 32.5kW arrayof German-manufactured Hanwha Q-CellsQ.Pro polycrystalline panels, along with three3-phase 10kW Steca grid tie inverters. If thearray produces unusable electricity, that powercan be sold onto the grid.

PV Tech’s Mike O'Rourke says that the PV arraywill produce around 28,000 kWh of electricityper year – equivalent to approximately 68,000kWh of primary energy usage and 15,000kg’s ofcarbon emissions reductions, as well as anannual energy saving of between €4,000 and€5,000. It’s estimated that the huge PV arraywill pay for itself within ten years.

Post planning design development also sawhalf of the cottage roof facing the drum beingomitted to create a roof terrace. Opening slatefinished apertures in the cottage roof allow westsunlight and views from the canteen. “With thebest of intentions, you can only envisage so muchat planning stage,” Michael Regan says. “You’regetting into the nuts and bolts of the schemewhen the full design team are integrated. They’veall their respective hats on, all pulling in thesame direction as the client. That’s when theseopportunities open up to the betterment of theproject.”

The cedar wood drum which anchors the entireproject was originally envisaged at planningstage as being formed entirely in glass withlocalised timber screening, but as the teamworked through the plans and environmental �

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(above) Close up detailing of the cylindrical wood drum’s cedar cladding; (below) a plan of the ground floor,showing the layout of the offices and the large warehouse at the rear; (left) the 2.5 storey drum anchorsthe entire project and was originally envisaged in glass, before the client opted to go for the timber design;(p57, clockwise from top) discrete movable slate panels provide light and views to the terrace without imposing;the building’s 217 sq m solar PV array and Supergrund insulated foundation system.

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details and calculations, it was clear that inaddition to threatening the budget, glare andoverheating issues would inevitably requirethat substantial expanses of the glass drumbe obscured. Bart Arnold, very much a hands-onclient, opted instead for the oiled cedar finish. Notalone did it achieve the aesthetic he wanted,but it also added to the timber used in the build,which was another project imperative.

At tender stage the invitations to tender werebased on block work built details and specifications,but timber frame pricing was also invited as analternative. MMD Construction won the contractbased on a block built structure, Michael Reganexplains. It quickly emerged however that sus-pending the drum on block would lead to anassortment of engineering headaches and po-tential thermal bridge details. Post tender MMDproposed a timber frame structure which madethe engineering work considerably easier.

Passive design always favours the lowest surfacearea to volume ratio as possible. The dispersedlayout of the TVM building required substantialattention to detail, both in terms of achievingairtightness and eliminating thermal bridges– two of the central challenges of passive house.A Supergrund insulated foundation underliesthe three office buildings, eliminating thermalbridging issues at ground level.

Joe Blair of MBC Timber Frame who suppliedthe frame for the three office structures – cottage,drum and two-storey – says that this elementof the build passed off without a hitch. “We’vedone about sixty or seventy houses to passivestandards at this stage,” he says. In Bartlemy,MBC provided a twin wall system, a 300mmtwin wall pumped full of cellulose insulationfrom Cork-based manufacturer Ecocel.

The building is accessed via a contemporaryzinc-clad, glass-panelled entrance porch, whichis positioned outside the thermal layer, andleads to a naturally-lit double-height entrancefoyer. The office suites inside are centred arounda bespoke triple-glazed roof light, which providesdaylight down to ground level. The board room,offices and canteen area at level one are accessedfrom a steel and glass staircase concentric to thedrum itself. The engineering workshop is clad inan architectural panelling system and providesaccommodation for servicing and support for thecompany’s large mobile recording studio trucks.

Heating comes from an air to water heat pumpsystem, while a 6 sq m flat plate Daikin solarthermal array assists with hot water needs. HughFoley of RTS Heating & Cooling supplied thebuilding’s renewable heating systems, includinga Daikin Altherma 16 kW low temperature air towater heat pump, with a certified SPF of 355%.“Obviously it’ll do a lot higher in hot weather, andlower in very cold weather,” says Hugh Foley.“Hot water demand takes priority on the heatpump. Ultimately down the line if they wantedto put a cooling coil onto the HRV unit – whichwould be a small modification – this heat pumpmodel has the potential to be reversed forcooling.”

Foley also connected the heating technologyto the building’s two heat recovery ventilationunits – one for the toilet block, one for the rest ofthe building – both have water battery heatersbuilt in, which are supplied hot water by theheat pump. The toilet block is heated to 18C.The design temperature for the rest of thebuilding is 20C. “The controls on them are in-

tegral,” Hugh says. “If there’s a heat demandover and above what the MVHR is able to do,they send a signal to the heat pump to pro-vide low pressure hot water to the heater bat-teries. That’s modulated by two 3 port valveson the pipework to the MVHR.”

Rainwater harvesting has been provided, pri-marily for truck cleaning and grey water recyclingfor toilets. Sensor flow taps have been fitted inbathroom basins and staff showers and thereis PIR lighting throughout circulation and allnon-office areas.

Completed now since May 2012, Michael Reganacknowledges that there have been the in-evitable teething issues as people get usedto working in a new space. “It’s no surprise inopen plan offices that some users are veryhappy with their environment whereas someare cold at 20 degrees. The client has comefrom a bungalow across the yard. It had cubi-cles and I’ve no doubt that they had little blowheaters that could have cranked up the heatwhen they wanted, so there’s a certain amountof personal adjustment required from eachworker. However the design team and sub-contractors acknowledge post occupation thatthere have been temperature and ventilationbalancing issues that required adjustment andseasonal monitoring over the first 12 monthcycle.”

Both architect and M&E engineers MalachyWalsh and Partners have been monitoring thebuilding closely over the past twelve months,with passive house specialists Wain MoreheadArchitects brought in to assist with finalisingcommissioning and to iron out any thermal com-fort issues that were being experienced. Ac-cording to John Morehead, PHPP – includingsite specific climate data – is being used in thiscase as a design review tool to assess the build-ing’s performance in passive house terms toassist with the final commissioning of the overallsystem, rather than to achieve passive housecertification.

“Using PHPP, we were able to focus on a num-ber of key areas that might need adjustment,”John says. “Through the use of strategicallypositioned data loggers, the results of any re-sultant tweaks can be closely monitored.”

According to John, while the building fabric isstreets ahead of conventional non-domesticbuildings, particular attention needs to be paidto addressing and redistributing localised in-ternal gains specific to the nature of businessfor a company like TVM, such as in the serverroom. “We found that the performance of thebuilding envelope was well up there in passivehouse terms,” he says. “But the impact of internalgains and radiant asymmetry on comfort couldbe significant. It’s interesting to note that theinternal heat gains were some six times that ofsolar gains, and wouldn’t necessarily be evenlydistributed throughout a building of this type.The balancing of heat distribution and air qualitythrough the use of the HRV systems in this buildingtype is of paramount importance.”

Some overheating has occurred as the buildingbeds in, most notably during the hot spell duringthe summer of 2012. According to Michael Regan,this has involved refocusing the supply andextraction of air to get a better balance betweenthe heat sources – such as the server room,which was generating more heat than anticipated asTVM’s server equipment was finalised – and �

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the open plan areas. “Data loggers have beeninstalled in three locations within the building andthe design team are to use the informationprovided to make final adjustments to the lo-cation and redeployment of air extract grillesto maximise air-movement and heat transferwithin the building.” he says.

Bart Arnold points out too that the situation iscomplicated by large variations in occupancyfrom one day to the next. “You can have a baselevel of 15 but then it goes up to maybe 50 becauseon weekends, most of the staff are out on theroad working, so it’s not that we have an officethat has 40 people here nine to five. Thereare quite a number of unique features here aswe learn how to use the system.”

He has no doubt however that with a little furtherexperimentation, these issues will be thoroughlyironed out. “We’ve made big progress over thelast few weeks and the building performed muchbetter during the recent heat wave,” Bart says.

“We wanted to design and build a building thatwas different, number one, and then as ecologicallyfriendly as we possibly could�We’re happy inthe work environment we have here. It’s anongoing learning curve, and from that point ofview it’s an interesting challenge in itself.”

SELECTED PROJECT DETAILSClient: TVM Television Mobiles Ltd

Architect: E-Project Chartered Architects LtdCivil, Structural & M & E engineers:Malachy Walsh and PartnersQuantity surveyors: Michael Barrett Partnership Main contractor: MMD Construction Ltd. Mechanical contractor: Integral MechanicalElectrical contractor: FusionAirtightness tester: Premier Energy RatingPHPP analysis: Wain Morehead ArchitectsHeating & ventilation: RTS Heating and CoolingTimber frame: MBC Timber Frame LtdWall insulation: EcocelWindows, doors & roof lights:Window and Door Co. / Duggan Systems LtdPhotovoltaic supplier: PV TechInsulated foundations: Kingspan AerobordCellulose insulation: EcocelAirtightness products: SigaOSB: SmartplyHeat pumps: DaikinMVHR: Air Trade CentreCladding supplier: J P CorryGreen cements: Cronin ConcreteFlooring: Experto Flooring






PROJECT OVERVIEW:

Building type: 1250 sq m office and workshopbuilding

Location: Bartlemy, Fermoy, Co. Cork

Completion date: client handover in May 2012

Budget: Circa €2.1m construction costs

Passive house certification: not certified

Space heating demand (PHPP):9.75 kWh/m2/m2

– based on preliminary PHPP analysis. Note– the impact of internal heat gains on the lowspace heating demand is significant.

Heat load (PHPP): preliminary estimate of10.95 W/m2 based on incomplete data

Primary energy demand (PHPP): notestablished

Airtightness: mid construction test result of0.521 ACH

Renewable heating system: 16 kW DaikinAltherma low temperature air-to-water heatpump with an EN14511-2:2000 certified SPFof 355%, combined with a 6 sq m Daikin flateplate solar thermal array with hot water priority,feeding water battery heaters in the MVHRsystem subject to demand.

Ventilation: two Caladair Carma mechanicalventilation systems with heat recovery. Counterflow heat exchangers with an EN 308 certifiedefficiency of greater than 90% under the fol-lowing conditions: fresh air -10C / 90% RH,- Return air 20°C / 50% RH.

Electricity: a 217 sq m 32.5kW Hanwha Q-CellsQ.Pro solar photovoltaic array, with three 3-phase 10kW Steca grid tie inverters.

BER: not available

Ground floor: Supergrund insulated foundationand rising wall with 150mm structural concretefloor slab on three layers of 100mm thick EPS100 insulation on radon barrier. U-value of 0.15predicted from preliminary PHPP analysis.

Rendered walls: factory built 300mm widetwin walled timber frame system filled withEcocel cellulose insulation with Siga airtightmembrane and tapes used throughout. 12.5mmplasterboard finished 50mm wide servicescavity provided inside the thermal/airtight break.9mm thick OSB sheeting to 50mm air cavityprovided between timber frame and externalblockwork finished in acrylic self-colouredrender system. U-Value: 0.125 (predictedfrom preliminary PHPP analysis).

Timber clad walls: factory built 300mm widetwin walled timber frame system filled with Ecocelwith Siga airtight membrane and tapes usedthroughout. 12.5mm plasterboard finished50mm wide services cavity provided insidethe thermal / air tight break. 9mm thick OSBsheeting to 2 x 75mm ventilated cross battenedcavity supporting 20mm thick lapped cedarboarding. U-Value: 0.126 (predicted frompreliminary PHPP analysis)

Roof to main office: Siga air tight membraneto underside of 300mm deep structural timberI-beam section and 90mm rafter zone filled witha total of 390mm of cellulose insulation and18mm OSB sheeting, with 20mm thick asphaltroof finish laid to minimum falls. U-value: 0.104

The roof to the roof terrace is of a similar con-struction, but excludes the 90mm rafter zoneand 90mm cellulose insulation. U-value: 0.14

Windows: Viking Aluclad triple-glazed unitsand external doors. Argon gas-filled units pro-viding an average U-values of 0.87 for fixedunits and 0.90 for multi-paned units with tilt andturn opening sections.

Green materials:American red cedar cladding,Ecocel cellulose insulation, 50% GGBS cementin foundations

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1970s Devon homebecomes certified passive B&B

If you’ve ever wondered what it’slike to live in a passive house, a B&Bin Devon could be just the ticket.The winner of the private housingaward at the 2013 UK PassivhausAwards, this upgraded 1970s homeproves that even existing buildingscan be made passive.


This bold retrofit project may be in Devon, butthe story behind it starts in Wales.

That's where architect Janet Cotterell of CTTSustainable Architecture met IT professionalAdam Dadeby. Both were studying for a mas-ters in advanced environmental and energystudies at the Centre for Alternative Technology,Machynlleth.

Adam's interest in energy policy had attractedhim to the masters. But as time went on, thearchitectural side of the course drew him in.

Concerned about energy security and climatechange, he planned to sell his London home andmove to the south-west of England to build alow energy, ecological home. The passive houseconcept hooked him.

"It's very evidence based, and it's pragmatic," hesays. "I'm not a very hair-shirt green, I like to becomfortable."

His initial plan was to build new, but the difficultyof finding land and getting planning permissionnipped that in the bud. Together with his wifeErica, he bought a run-down cavity-wall houseon a modernist estate in Totnes, Devon, andplanned to retrofit.

"I can't think of any part of the house that wasn'twrecked," he says. "Except for total structuralcollapse, everything else you could think of wasa mess." Enerphit, the Passive House Institute'sless onerous standard for retrofit, didn't exist atthe time, so Adam aimed for full passive housecertification.

He interviewed other architects, but ended uphiring Janet. The two interviewed a handful ofbuilders and – rather than going to tender –selected Jonathan Williams, whose backgroundis in conservation building, and negotiated a pricewith him. "Jonathan understood what passivehouse was all about," Adam says. Accordingto Janet, Jonathan was the only builder theyinterviewed who had read up on passive house,and understood how hard it would be. “Jonathan'sconservation background meant he knew totake care,” Janet says. “And he had a team oftrades that he worked with regularly, which helpedgreatly.”

The first step was to externally insulate the house.Adam wanted to use a natural material, but doingso would have resulted in very thick walls. What'smore, the team couldn't heavily insulate theground floor (though they did put in 80mm ofphenolic and 20mm of woodfibre insulation here)without lowering the room height or undertakingexpensive groundworks. So in order to hit thepassive house standard, they had to compen-sate by pushing the thermal performance �

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of the walls even further.

That meant using a high performance, syntheticinsulation — 180mm of Kingspan K5 phenolicboard — rather than a natural material. Theexternal insulation helps to eliminate thermalbridging too.

The existing wall cavity was filled with poly-styrene Instabead, while insulating autoclaveaerated concrete blocks were used to rebuild andextend wall sections that were close to collapse.Upstairs, the team extended the building up-wards to add a third floor and insulated the newroof with Warmcel cellulose insulation – made

from recycled newsprint – plus Thermafleecesheep’s wool in the service cavity.

Janet designed a new 30 square metre timberframe extension that serves as an entrance area.The walls and roof feature Warmcel-insulatedSteico I-joists plus sheep’s wool-filled servicecavities. There's also a "living roof" plantedwith local wildflowers.

"I just like the idea of the small section timberI-joist, using low grade timber, and using aslittle of it as possible, and using the recyclednewspaper [insulation]. It just seemed a sensibleuse of materials to me," Janet says.

The whole house scored 0.40 air changes perhour on its first airtightness test, and a jaw-dropping 0.2 at certification.

According to Janet, this result is down to meticulousdetailing and education across the project team."We didn't end up having an airtightness championbecause everyone was the airtightness champion,"she says. “Everything was very carefully planned,so that virtually no changes were needed on site.”

The team chose triple-glazed Internorm Varionunits and Varion 4 ‘2 + 1’ units, which featuredouble-glazing plus an integrated blind — tocontrol overheating — that's enclosed by a thirdpane of glass.

These later units have an average overall U-valueof 0.93, which may not be sufficient for passivebuildings in colder climates, but are suitablefor mild south Devon.

Janet paid close attention to shading design,and says the house stayed cool during thissummer's heatwave. "We did the shadingsquite well. It's one thing with PHPP you can fudgea bit," she says. Designers must get shadingright to prevent overheating, she says, otherwisepeople will say the passive house conceptdoesn't work.

"The house is very comfortable and our billsare very low," Adam says. Internal temperaturesare steady, and when they change they do sovery gradually. The only major overheatingproblem occurred when over 150 people attendedan open day at the house during a spell of warmweather.

But during the cold winter of 2012, the groundfloor was actually a little cooler than upstairs— most likely because the floor is only insulatedto a U-value of 0.2, and because there's athermal-bridge at the wall-floor junction.

Janet says there's an important lesson here: thatwhile passive house designers can compensatefor less-insulated surfaces by adding more in-sulation elsewhere, for comfort every opaquesurface in the external envelope should ideallyhit the recommended maximum U-value of 0.15.

The house's only source of mechanical heatingis the heat recovery ventilation system, which �

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(above left) Windows are bracketed onto walls prior to external insulation installation to ensure a con-tinuous insulation layer; (above right) south facade with completed insulation before rendering; (below,clockwise from top left) Foam Glas insulation under the toe of the slab with 200mm Xtratherm PIR; SteicoI-joists form the roof structure; view down towards south west including 50mm existing cavities; air-tightness taping around joists; (p63, above, left to right) architect Janet Cotterell & client Adam Dadebyreceive the passive house certificate from builder Jonathan Williams, pictured with build team memberJoe Bellows with passive house certifier Peter Warm); (below) the extension features a living roof; andbright, sleek yet ecological kitchen.

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includes a small duct radiator in the supply airthat's fuelled by a little gas boiler. Adam’sthinking of adding a radiator downstairs to de-liver more heat there, but might take out theduct heater if he does.

"I was quite determined not to have radiators,and I should have been more pragmatic," Adamsays. He admits that not installing a full centralheating system was akin to taking a leap of faith.

But he's still very comfortable — during his firstwinter the duct heater had yet to be installed,but he heated the whole house to about 19C witha small oil-fired radiator on its lowest setting (400W).

Solar thermal panels contribute to the house'shot water, and Adam also installed a solar pho-tovoltaic array with a 4kW peak output. He in-stalled PV partly for environmental reasons,but also because the feed-in tariff on offer atthe time was quite generous. "Purely in moneyterms it was worth it," he says.

But the solar thermal and PV panels are facingwest and east respectively, a constraint of theplanning conditions. "Our wintertime renewablesgeneration is consequently much lower," Adamsays.

Perhaps surprisingly, in hindsight he's unsurewhether such a deep retrofit is always the rightsolution for projects like his — in economic orenvironmental terms.

Building a new house, he reckons, would havecost less (principally because he would have gota big VAT discount for new build). And in carbonterms, he would have been able to use natural, lowembodied energy materials throughout the build.

Nonetheless, the project won in the privatehousing category at this year's UK PassivhausAwards and the whole Totnes team — Adam,Janet, Jonathan — went on to collaborate onvarious projects.

The trio have since founded Passivhaus Homes,a design-and-build passive house firm that isdeveloping a 'kit-based' approach to buildingpassive homes to bring costs down. They'vejust completed their first prototype. The company

is also looking at working with community landtrusts to develop new, affordable passive homes.

"We feel this is a much better way to deliver lowcost housing to the people who need them,"Janet says. "It cuts out the commercial profitdriven volume house builders and puts thelocal community back in the driving seat."

The trio have also launched a web business,the Passivhaus Store, which aims to streamlinethe supply of passive house suitable buildingmaterials and systems. Adam and Janet havealso written The Passivhaus Handbook, whichis published by Green Books/UIT. "The bookis a distillation of what we've learned from theproject," Adam says.

Meanwhile, Adam and his wife Erica have openedup their Totnes passive house as a bed and break-fast. Adam says half their guests are peoplethinking of building their own passive house, visit-ing to get a taste of what it's like to live in one.

So, if you really want to get a feel for the project,you could always go and check it out for yourself.

Adam blogged extensively about the projectat http://passivhausrefurb.blogspot.co.uk

SELECTED PROJECT DETAILSClient: Adam Dadeby & Erica AslettArchitect: CTT Sustainable ArchitectContractor: Williams & PartnersPHPP: Adam DadebyPassive house certification: WarmAirtightness consulting & testing: AldasExternal insulation (retrofit): KingspanCellulose insulation: Warmcel, installed by EcofillSheep’s wool insulation: ThermafleeceWood fibre insulation: SteicoCavity wall insulation: InstabeadInsulated foundations: CelotexAirtightness products: Ecological Building SystemsWindows: InternormMasonry thermal blocks: Travis PerkinsThermal breaks: FoamglasPlaster: British GypsumMVHR: PaulSolar thermal & modulating boiler:Rotex, supplied by Responsible Energy ManagementPV array: MobasolarPV inverter: Fronius






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PROJECT OVERVIEW:

Building type: 162 square metres retrofitted& extended cavity-wall detached house including30 square metre timber frame extension.

Location: Totnes, Devon

Cost: £330,000 construction plus £44,000for architectural and other professional fees

Passive house certification: full certificationachieved

Space heating demand (PHPP): 13kWh/m2/yr

Heat load (PHPP): 9.3W/m2

Cooling load (PHPP): 4W/m2

Primary energy demand (PHPP): 68kWh/m2

Primary energy demand (measured): 76kWh/m2

Airtightness: 0.2 ACH

Upgraded walls: 180mm rendered KingspanK5 phenolic external insulation on 100mmoriginal block, followed inside by 50mm cavityinsulated with Instabead Graphite K32, thenanother 100mm block. U-value: 0.095

Upgraded ground floor: 14.5mm Kährs hard-wood floor finish on 2mm foam underlay, fol-lowed underneath by 20mm Steico woodfibreinsulation, 80mm Kingspan K3 insulation, 10mmplaster and original 150mm slab. U-value:0.2. Glapor foamed glass gravel insulatingaggregate outside three perimeter walls.

New roof on existing dwelling: 24mmwoodfibre board externally, followed below byI-joists with 350mm Warmcel cellulose insulation,50mm service cavity insulated with sheep’swool, plasterboard. U-value: 0.104

Extension walls: 24mm woodfibre boardexternally, followed inside by vertical I-joistsinsulated with 400mm Warmcel cellulose in-sulation, 50mm sheep’s wool-insulated servicecavity, and plaster board internally. U-value 0.093

Extension floor: Kährs hardwood floor asabove, on 20mm Steico woodfibre insulation,50mm sheep’s wool batts, 150mm slab, and200mm Xtratherm PIR insulation. Two coursesof Foamglas Perinsul blocks at perimetersunder toe of slab. U-value: 0.075

Extension roof: OSB board externally, followedbelow by I-joists with 350mm Warmcel celluloseinsulation, 75mm sheep’s wool insulated cavity,and 12mm plasterboard. U-value: 0.107

Windows: Internorm Varion triple-glazed windows/Varion 4 ‘2 + 1’ glazing. The Varion 4 units haveintegrated blinds for summertime shading.Spacer-psi value 0.05W/mK, g-value 0.6 onsolar gain facades, double e-coated, Argonfilled. Overall U-values: 0.75-0.93

Heating: post heater in MVHR supply air fuelledby 20kW Rotex gas boiler (modulates downto 4kW). Plus 9.4m2 of west-facing Rotexroof-integrated solar thermal drainback panelswith Rotex 500 litre thermal store.

Microgeneration: 3.99kWp Mobasolar photo-voltaic array with Fronius IG TL transformerlessinverter

Ventilation:MVHR Paul Novus 300, 0.24Wh/m3,93% HR efficiency

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CORK HOMEhits 94% heat reductionwith Enerphit

The vast majority of energy upgradeprojects aim for low hanging fruitmeasures, and risk locking buildingsand their occupants into needlesslyhigh energy usage, environmentalimpact and discomfort. This recenthome upgrade on the outskirts ofCork City shows what truly deepretrofit looks like.

Words: John Hearne

Prior to Elite Architect’s renovation of a 1950shouse in Co Cork, architect Andrew Shortenused passive house software to estimate itsannual heating bills. When the figure came inat a staggering €5,500, he did a double-take.

“It sounded a lot,” says Shorten, “but when Ithought about it, my own rule of thumb for aten-year old house built to building regulationsis that it costs about a Euro per square foot peryear to heat, and this house is 1950s, singleglazed with zero insulation and 2,500 sq feet.That €5,500 mightn’t be far off.”

When Shorten performed the calculations againafter the renovation, he found that the cost ofheating the house had fallen to just 6% of theoriginal figure.

The drive for Enerphit, the Passive House Institute’sstandard for renovations, came from Elite. Shortensays that he simply recommended that approachfor the job and the client agreed. “At the timethey were renting an old house in Blackrock inCork. I was talking about an airtight house, andthey had drafts coming up from under the floor-boards, so they were able to contrast what we wereaiming for with the wrong end of the spectrum.”

While Enerphit standards are not as exactingas passive house, design professionals willtell you that achieving those standards canactually be more challenging. A new build of-fers a wider choice of design and constructionoptions. When you have to work with and re-tain large sections of what’s already there, itfrequently requires more imagination and amore exacting spec to hit the targets.

“There was a rustic character to the house,particularly as you approach from the road, andwe felt we didn’t want to lose that character,”says Shorten. “It hadn’t been touched in years,so it needed a significant overhaul in terms ofperformance, electrics, plumbing, heating, in-sulation and aesthetics, and we also neededto transform it into a tasty house to live in. In fact,it was kind of obvious what the brief was.”

One thing the project had in its favour was ori-entation. The living areas of the house alreadyfaced south, benefiting from passive solar gains.To increase those thermal gains still further, anextensively glazed one room extension was added.A sloped garden facilitated dropping the floorlevel here, allowing the design team to createa four metre high living space surrounded by adouble-height glazed wall. In order to both connectoutside and inside, and to provide summer shad-ing, an overhang was created at this elevation.

Contractor the Green Build Centre had workedon passive house projects before, but this was �

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their first Enerphit renovation. “We were very luckyto be honest,” says project manager Mark Higgins,“because basically the house was strippedback bare. In that respect we had a blank canvasto work with. We stripped out the whole building,ceilings – the lot.”

Retaining the external look of the house meantruling out one approach that tends to featureprominently in Enerphit projects: external insulation.But because it was such a big, boxy house, therewas sufficient room to accommodate additionalinsulation internally.

The team then turned its attention to eliminatingcold bridges and achieving airtightness. AndrewShorten points out that external insulation, inaddition to affecting the house’s character, canadd a further challenge in a retrofit situation. “Withexternal insulation, there’s now a huge gap betweenthat insulation and the insulation under the floor.”

Shorten argues that insulating internally put himin a better position when it came to designingaway cold bridges. Cutting away all floors andceilings allowed the contractor to completelydryline internal walls. Installing new insulation

beneath the floors and in the roof then allowedthe team to effectively create a continuous, almostunbroken layer of insulation inside the house.

“If you draw a section through the house,” Shortenexplains, “floor meets wall perfectly, wall goesthrough first floor perfectly, bar timber joistsbridging, which isn’t a major deal. Then it goesup and meets the 450mm of attic insulation.

“All of the internal walls meet the external walls,creating a break in the insulation but we pumpedthe cavity with 100mm of bead, so that thermal

bridge was nullified by the fact that there was moreinsulation out beyond it. It meant the compromisethere was really minor.”

Airtightness was then achieved through acombination of OSB board and Siga tape. As hasbecome increasingly common now, the buildcontract was subject to a substantial retention– in this case €30,000 – on achieving airtightness.

“We have a system where one person is in chargeof the airtightness from start to finish on the project,”says Mark Higgins. “That one person is basicallyonsite all the time. He’s project leader.”

“When a trade finishes he’ll inspect, and he’lladvise before the trade starts as well. Whenyou tell people that airtightness can cost anythingbetween €5,000 and €10,000 they really don’tunderstand why – sure it’s only tapes and plastic.They don’t understand the amount of labour thatgoes into achieving it.”

He adds that he treats airtightness as a process,and that he doesn’t tend to make any moneyon that aspect of the build. The first and onlyairtightness test recorded 0.9 ACH, comfortablywithin the Enerphit limit of 1 ACH.

Heat now comes from a gas boiler, while a heaterbattery in the mechanical heat recovery ven-tilation system provides backup. “Because theextension is virtually all glazed apart from onewall,” says Shorten, “there was a risk of it beingvulnerable to cold in the winter because of ex-cessive heat loss, so that area has a separatezone heated by underfloor heating. We’vefound that that works perfectly.”

The new triple-glazed windows from Slowinscydeliver overall U-values of 0.7, while a bespokerooflight over the office area, put together onsiteby the contractor, was also designed to meeta 0.7 U-value.

Despite achieving Enerphit standards, so farneither client nor architect have opted to seekcertification from the Passive House Institute.“It wasn’t high on our priority list.” Shorten admits.“But it’s at the standard. While we may go for itin the future, we haven’t pushed our client to getcertification because it’s an expensive process.”

The clients are now in the house for seven months.There has been the usual adjustment period asthey get used to how a passive space works.“I think it takes a little getting used to from aclient’s point of view. We’ve experienced thatwith other clients as well. Once they’re in thehouse six months and they understand things,they get happy with it.”

“The whole project went quite smoothly,” saysMark Higgins. “The architects were onsite everyweek which is very important. If you have aproblem, it can be dealt with quickly. The biggestwatch-out factor is that everyone is talking allthe time, and everyone understands what’shappening next.”

SELECTED PROJECT DETAILSClients: AnonymousArchitect/passive house consultant:Elite ArchitectsEngineer: Foundation & DesignMain contractor: Green Build CentreEnergy rating assessment: Brian Ronayne Heat recovery ventilation:ProAir, installed by Munster HRVInsulation to floor and walls: Xtratherm �

To shed some light on how thermal bridging calculation

varies between Ireland and the UK's national methodologies

and the passive house approach, insulation manufacturer

Xtratherm's Mark Magennis carried out some thermal

bridging modelling of the wall-ground floor interface de-

tail in this building. Qualified under the BRE and NSAI

schemes to carry out thermal modelling assessment in

Ireland and the UK, Mark's modelling reveals strikingly

different results for the same detail. Deap and Sap – re-

spectively the Irish and UK methodologies for determining

compliance with minimum energy performance standards

under building regulations and for generating energy

ratings – model thermal bridging based on internal meas-

urements. The Passive House Planning Package (PHPP)

takes a different approach, using external measurements.

As a consequence, in this case the same detail shows a

Psi-value of 0.049 to input into Deap and Sap, or 0.0022

for PHPP.

"In reality it's the same amount of thermal bridging," says

Xtratherm's Danny Kearney. "PHPP seems daunting

because the thermal bridging targets of 0.01 seem so low

but as we head towards zero energy and zero carbon

standards, the requirements in our national methodologies

set more onerous PSI-value targets, so passive house

thermal bridging performance can be achieved using rea-

sonable specifications. When you actually do the con-

version from national methodologies to PHPP, you may

be surprised - you may have achieved a better Psi-value

than you thought."

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Cavity wall insulation: Thermobead, installed by Dungarvan InsulationRoof insulation: KnaufAirtightness products: SigaOSB: SmartplyBreather membrane: Ecological Building SystemsThermally broken cavity wall ties: AnconWindows & doors: SlowinscyRoof windows: Cork Glass/VeluxCondensing boiler: VokeraKitchen/fitted furniture: Creative Designs






PROJECT OVERVIEW:

Building type: renovation and extension toa 1950s detached house

Location: Cork

Completion date: December 2012

Budget: confidential

Enerphit certification: application has notyet been made.

BER (before): unknownBER (after): B1 (92.68 kWh/m2/yr)

Space heating demand (PHPP)

Before: 226 kWh/m2/yrAfter: 12 kWh/m2/yr

Heat load (PHPP)

Before: 103 W/m2

After: 11 W/m2

Airtightness (at 50 Pascals)

Before: UnknownAfter: 0.92 ACH

Original walls

Before: blockwork with un-insulated cavity.U-value: 2.0After: platinum EPS insulation to existing80-90mm cavity; 100mm Xtratherm Thin-RPIR insulation internal drylining; Smartply OSBairtight/vapour control layer with all joints tapedwith Siga tapes; 38mm Xtratherm PIR insulation;plasterboard with skim finish. U-value: 0.11

Extension walls: blockwork with 100mm cavitypumped with full fill bead insulation, TeploTie lowthermal conductivity wall ties; 100mm XtrathermThin-R PIR insulation internal drylining; OSB air-tight/vapour control layer with all joints taped; 38mmXtratherm Thin-R PIR insulation; plasterboardwith skim finish. U-value: 0.11

Existing roof

Before: pitched, hipped A-frame roof to existinghouse with concrete roof tiles. U-value: 2.3 W/m2KAfter:PVC single ply roofing membrane; 300mmmineral wool insulation on the flat betweenexisting roof joists vapour barrier; 50mmservice cavity; plasterboard ceiling. U-value: 0.09

Extension roof: PVC single ply roofing mem-brane; single ply membrane finish; WBP ply-wood; 50x50 battens to create ventilatedvoid; Pro Clima Solitex Plus breather mem-brane; Firring pieces to create falls; 425 mmEco joists with 450mm Knauf Loft roll be-tween joists; Siga Majpell vapour barrier andtapes; 50x50 battens to form service cavity;plasterboard with skim finish; U-value: 0.11

Floor: original suspended wood floor removed,roughly 400mm of 804 aggregate imported andcompacted; radon barrier; 150mm of Xtratherm PIRinsulation; 150mm concrete slab. U-value: 0.11.

Thermal breaks:100mm wide strip of XtrathermPIR fixed to the base of the external wall at300mm beneath floor level, meeting 150mm ofXtratherm laid horizontally beneath 150mm ofconcrete – and used to level concrete pour.

Windows & doors

Before: single-glazed, aluminium windows. After:new triple-glazed Slowinscy Thermax Ultratimber alu-clad windows. Overall U-value: 0.70

Roof windows: triple-glazed unit to flat rooffrom Cork Glass. U-value: 0.7. Velux triple-glazedrooflight. U-value: 1.0

Heating system

Before: existing boiler and radiators throughoutentire buildingAfter: Vokera Combi gas boiler, 97% efficiency,underfloor heating to extension only. Heatingbattery in ventilation unit, with heat distributedthrough HRV system to all rooms.

Ventilation

Before:no ventilation system. Reliant on infiltration,chimney and opening of windows for air changes.After: ProAir PA 600 HRV with Sap AppendixQ rated efficiency of up to 94% and specificfan power down to 0.57 Ws/l, with in line heatingbattery fabricated by ProAir.

upgrade

(above) As the living areas of the house weresouth-facing, an extensively glazed extensionwas built to make the most of the solar gains.The sloped garden facilitated in dropping thefloor level, allowing the design team to increasethe height of the extension; (p67, clockwisefrom top left) airtightness was achieved througha combination of OSB board and Siga tape;Knauf Earthwool insulation in the flat roofof the extension; an overhang provides summershading.

“The house was stripped backbare. We had a blank canvasto work with.”

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It makes sense to retrofit buildings. Economicoutput is increased, jobs are created in the dormantconstruction sector, and exchequer financesare bolstered.

Investing in buildings is also unquestionably thekey to unlocking the near-term decarbonisationchallenge in the UK, Ireland and many otherEuropean countries. Broader benefits includegreater asset values, increased productivityand competitiveness, fuel poverty alleviation,greater energy security, and reduced governmenthealth expenditure.1

Investments in the homes are particularly labour

intensive. Yet it’s difficult to convince homeownersto take action. Efforts to promote investmentsface intractable challenges, often resulting inonly slow or marginal behavioural change onthe ground.

The installation of grant-supported cheap meas-ures with short paybacks prevails. Deeper morecomprehensive retrofits, which in many casesconstitute an excellent investment proposition,remain something of a white elephant – muchtalked about, but rarely encountered.

A central issue surrounds the shortage of up-front investment cash, sometimes referred to as

a financial barrier. This barrier interacts with anumber of complicating behavioural, cultural,social, and informational barriers. Where deeperretrofits are concerned, with payback periodssometimes in excess of 20 years, the split in-centive is also an issue – the investor may sellon the property in due course, and the nexthomeowner becomes the beneficiary.

An emerging trend, particularly in the UK andIreland, is a shift from grant-based support. Theobjective is to establish a sustainable market-based approach to retrofit, with minimum exchequersupport. This is a welcome development – grantprogrammes result in boom-bust investment

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Unlocking investment

IN HOME RETROFITLessons from the UK and Ireland

In spite of a consensus that most buildings need deep energy upgrades, both Ireland and the UK havebarely scratched the surface. Joseph Curtin – one of Ireland’s leading energy policy wonks –discusseshow to kick start en masse upgrade work.

cycles, and are dependent on scarce exchequerresources. But ensuring a smooth transitionfrom grant programmes which incentivize shallowretrofits, to market-based approaches aimedat promoting deeper retrofit activity, is fraughtwith difficulties.

UK green deal or no deal?

The UK has taken the lead. The much-discussedGreen Deal attempts to address the financingbarrier by providing up-front funding to interestedhomeowners who want to invest in efficiency.They repay the loan as they save money on energybills over the years.

The electricity bill payer repays the investment,so that if a home is sold, the new owner takeson responsibility for the repayment stream(optionally, the loan can be repaid at this point).This is a key enabler of deeper retrofit activity.

Since the programme went live earlier this year,the number of homes installing cavity wall insulationand other measures declined significantly. House-holds used to receiving heavy subsidies formeasures are understandably reluctant to takeout what’s perceived as a personal loan.

While short-term teething problems shouldn’tcause concern, well-intentioned critics say thatthe programme is flawed. They argue that moneyis too expensive, with interest rates of sevenper cent the norm. This compares unfavourablyto mortgage products, which are becoming in-creasingly common in the market place. Forexample, Ecology Building Society charge 3.9– 4.9 per cent for mortgages for energy savinghome improvements.

UK Department of Energy and Climate (DECC)survey data2 shows that homeowners whohave had a Green Deal assessment still citefinance as the biggest barrier – the one thatthis programme was supposed to overcome.Homeowners are clearly saying “no deal”.

The principle of the debt attaching to the en-ergy meter has also come in for criticism, withmany arguing that it could act as a disincentivewhen it comes to selling the property. While soundin theory, this is certainly a new concept for con-sumers to grapple with. Like all such ideas, it’lltake a lot of explaining before it’s accepted inthe marketplace.

If works are undertaken, however, this means amore valuable property, more comfortable livingconditions and lower bills. Whether the sellerpays off the loan, or the buyer takes it on, therewill be a net benefit. I don’t see this as a problemin the medium-term. While it would be foolish toignore consumer feedback, the Steve Jobs maximthat “a lot of times, people don’t know what theywant until you show it to them” seems apposite.

Even if loans with competitive interest rates wereavailable, critics in the UK have argued that thiswould not be sufficient to drive widespread retrofit.Because of the fundamental newness of theoffering, and the cultural shift required, the UKGreen Building Council have argued that “longterm structural incentives would still be neededto ensure sufficient uptake”.

Ireland’s better energy?

Ireland too began with a grant-aided programme,which succeeded in breathing life into the res-idential retrofit industry. The numbers of housesundertaking retrofit under the Better EnergyHomes scheme first rose dramatically between

2009 and 2011. Activity has, however, declinedsignificantly in 2012 and 2013.

It should be noted that the average investmentfor a retrofit was €3,000, of which approximately€1,000 came from the grant. Although grantswere available for “deeper” measures such asinternal and external wall insulation, supportwas effectively targeted at shallow, cheap and“easy” measures: cavity wall insulation and roofinsulation.

Funding for retrofitting is to be phased out by2014 according to the Programme for Government,and a ‘Pay As You Save’ scheme, somewhat akin tothe Green Deal, is to replace the grant programme.

Better Energy Finance, an industry-lead initiativewhich is working with government to designthe scheme, offered some indication of the di-rection they will take. In a recent paper thegroup argued that “at this stage of the projectwe believe offering short payback measuresis a key part of building consumer confidencein the scheme and introducing them to a journey

of successive home improvements leadingdown a path to deeper retrofit”. They also de-cided that the idea of attaching debt to the energymeter was not a runner – this is consistent witha focus on shallow retrofit with short paybackperiods.

While an overall design has yet to emerge, andit is too early to be critical of these developments,it would appear that the group envisages con-tinuing the focus on shallow retrofit. Given thatapplications for these measures have collapsedeven with the availability of a grant, prospectsfor the programme may be somewhat gloomy.

On the other hand, if energy utilities are requiredto meet part of their energy saving targets re-quired under the EU Energy Efficiency Directivein the residential sector, there may be additionalsupport available to homeowners via their energycompanies. The Irish government has givenno indication yet how it intends to implementthe directive.

Four conditions for success

If the UK and Ireland are to succeed in the gen-erational programme of upgrading the hous-ing stock, action is required across a range ofareas. Short-term political wins must be sacrificedfor the objective of putting in place a programmewhich has the potential to deliver effectively overthe coming decades. A number of lessons havebeen learned from experience to date, whichcan guide future policy development.

One: the cost of money and exchequer support

The first lesson is reminding us of somethingwe knew already: seven per cent interest rateswill not work. If financing cannot be providedat more attractive rates over 20 to 25 year terms,

programmes aimed at promoting deep retrofit willfail. The point is illustrated by the case studies intables 1 and 2, based on data from the Irish market.We can see that deeper retrofits are only at-tractive as an investment proposition if moneycan be provided at low cost over longer terms.

Related to the above points, it’s likely thatthere will be a requirement for governmentsupport to overlap with financing offerings fora period of time. Withdrawing grants entirely andexpecting a market-based approach to take offis unrealistic. Whether grants should be main-tained (perhaps with an annual degression) �

insight

A close up view of platinum EPS bonded bead insulation. Up till now Ireland’s grant funded energy upgradework has centred on low hanging fruit measures such as pumping bead into cavity walls.

“Withdrawing grants entirelyand expecting a market-basedapproach to take off is unrealistic”

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or the cost of money is subsidised is a moot point,but some form of support must be provided.Another option is to provide support indirectlyvia energy suppliers, who are required to deliverenergy savings under the Energy EfficiencyDirective.

This shouldn’t be a difficult sell to policy makers.The case study below (again from the Irish market)shows tax revenue to government from the in-stallation of external wall insulation. Reducedsocial welfare and health spending are notconsidered, making this a low estimate.

As we can see from the above, the grant availablefor external wall insulation (€2,700) is easilyrecouped by the exchequer.

Two: go deep or go home

As is also illustrated from the above examplein table 1, bundling of measures with shortpaybacks (heating controls or attic insulation)with measures with much longer paybacks (ex-ternal wall insulation) is required for packagesto have reasonable payback periods. Programmeswhich cherry-pick loft and cavity wall insulationstherefore can work against comprehensiveretrofits, by making those interventions technicallyand economically implausible at a future date.

Additionally, we can see from the experiencewith Ireland’s grant-aided programme that shallowretrofit programmes can only be sustained ata high level for a short period, before interest

diminishes. Interested householders are limited,as are the numbers of interventions available.This is particularly the case with cavity wall in-sulation where the majority of low hanging fruitmay already have been picked. The only wayto build a sustainable industry is by focusingon deeper retrofits.

Three: using property taxes as supplementary

instruments

If we are to take this area seriously, a range ofsupplementary supporting measures are re-quired to encourage the magnitude of the shift

in society which is required. While a range ofdiscrete measures are required to target dif-ferent market segments (such as social housing,rented accommodation, heavily mortgaged prop-erties, apartments, houses and listed buildings),I’ll focus on one.

We know from empirical evidence that con-sumers are somewhat myopic when it comesto future energy costs implicit in the purchaseof an electrical appliance, a vehicle or a house.This is why we have regulations for the efficiencyof electrical appliances, and why car purchasetax and annual car tax rates reflects the efficiencyof vehicles. When these new calculation method-ologies for vehicle purchase tax and annualtax were introduced in Ireland to incentiviseefficient vehicles, the impact was an immediate:consumers shifted their car purchase decisionsdramatically in favour of efficient vehicles.

In the UK and Ireland, houses are taxed in thesame way as cars: there is a transaction tax atthe point of purchase and a property tax payableannually. These tax instruments can and shouldbe amended in a fiscally neutral manner to re-flect the efficiency of houses; the impact wouldlikely be equally dramatic.

Four: overcoming resistance in government

If success is to be achieved, policy makers mustnot be put off by the intractability of the challenge.A continued and determined focus, and thewillingness to trial, test, and refine policy inter-ventions is a necessary condition for success.

There is resistance in many parts of government,in particular in Treasuries, to investing in buildingenergy efficiency. This is particularly the casein the current climate of fiscal retrenchment. Thismay be because the impacts and outcomesof investing in residential efficiency are con-sidered somewhat uncertain.

By contrast, Treasuries prioritise more estab-lished areas of capital expenditure such as roadsprogrammes. This is perhaps because these areashave a clearly defined and predictable outcome,and an established and accepted methodologyexists where these outcomes can be establishedex ante.

Policy resistance within governments can beovercome with greater evidence on the benefitsof investment programmes. For example, Ire-land’s SEAI have undertaken a cost-benefitassessment of their investment programmeswhich show a benefit to cost ratio of 5:1 forsociety. A recent UK Department of Energy andClimate Change in the UK demonstrated thatasset value appreciation alone may cover thecost of retrofit in many cases. These are positivedevelopments which can be built upon.

Conclusions

Valuable lessons have been learnt from ongoingand past programmes aimed at promoting in-vestments in home retrofit activity. Ultimatelya cultural shift is necessary in society. A tippingpoint can be reached, where financing investmentsin residential energy efficiency is as commonas financing the purchase of a new vehicle.

While the shift from grants to more market-basedapproaches to promoting deeper retrofits couldbe successful, more focused efforts across arange or areas is required. Government supportis necessary for the transition, as are a rangeof supporting and flanking measures. Get thisright, and the UK and Ireland can be trailblazersfor other European countries.

Joseph Curtin (@jmcurtin) is a senior researchassociate with the Institute of Internationaland European Affairs, Dublin. He has workedfor the OECD, NESC (an advisory body tothe Taoiseach), and the Sustainable EnergyAuthority of Ireland, on climate and energypolicy-related issues.

1The multiple benefits of energy efficiency policy for Ireland arediscussed in more depth in Curtin, Joseph and Maguire, Josephine,Thinking Deeper: Financing Options for Home Retrofit, Instituteof International and European Affairs, Dublin, Ireland, September2011. For more general discussion see: IEA (2012) Spreadingthe Net: the Multiple Benefits of Energy Efficiency Policy, IEA: Paris.2bit.ly/14mxk4w

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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.

BREEAM This is the Building Research Establishment'sEnvironmental Assessment Method, a UK system used toassess the environmental impact of non-domestic buildings.It considers a range of criteria including energy consumption,water, materials, waste, transport, ecology, pollution andhealth. It has five levels: pass, good, very good, excellentand outstanding. As with competing rating systems such asthe US LEED and German DGNB systems, BREEAM isgaining popularity internationally, often used by public sectorand multinational clients.

Brise soleil A permanent structure designed to provideshade from the sun. In the northern-hemisphere these areoften placed on a building's south-facade to help preventglare and overheating. Some innovative approaches to brisesoleil include planting deciduous climbers to provide extrasummer shading and more passive solar gain in winter.

Building envelope/fabric The exterior ‘shell’ of thebuilding, including the external walls, windows, groundfloor and roof.

Code for Sustainable Homes The BRE’s environmentalassessment tool for dwellings. As with BREEAM (see above),buildings are assessed on their overall environmental per-formance, resulting in six levels of scoring.

District heating A type of heating system in which heat ispiped from a large central heating system (such as a boiler)to multiple units (such as houses or apartments), ratherthan each unit having its own separate heat source. Oftenfinanced via energy service companies (ESCos), districtheating systems tend to become less viable in very energyefficient buildings, given that the low space heating demandmeans smaller bills payable to the ESCos.

Enerphit This is the Passive House Institute's standardfor retrofit projects. It demands airtightness of 1.0 air changesper hour and space heating demand of 25kWh/m2/yr (asopposed to 0.6 air changes per hour and 15 kWh/m2/yr forthe original passive house standard).

Intelligent vapour check/membrane A type of membrane,often used in timber frame construction – and timber roofstructures – that becomes more or less permeable to watervapour depending on ambient conditions. Typically in winterit prevents water vapour from getting in but becomes morevapour permeable in summer to allow water vapour to diffuseout and building components to dry.

MVHR or mechanical ventilation with heat recovery, togive it its full name, also known as heat recovery ventilation.This is a system that ventilates a building while also re-covering heat from extracted air. It’s typically installed as acentralised “whole building solution, but decentralised systemsare emerging too, including single room ductless systems.MVHR systems typically extract warm, damp air from ‘wet’rooms like kitchens and bathrooms and use it to heat cool,fresh incoming air, which is then usually piped to livingspaces such as living rooms and bedrooms.

Performance gap The difference between how a buildingis designed to perform and how it subsequently does in realityonce built. The term usually refers to energy consumption

but can refer to other aspects of building performance too.

PHPP This is the Passive House Planning Package, thespreadsheet-based software that is used to design, verifyand certify passive house and Enerphit projects.

Psi (ψ) values This is the 'linear thermal transmittance',the rate of heat flow per degree temperature difference perunit length of a thermal bridge. It is measured in W/mK, andis used to calculate the heat loss or gain through a thermalbridge. Under Irish and UK building regulations, the Psi-valuesfor all non-repeating thermal bridges are multiplied by themeasured length of each bridge before a Y-value for thebuilding can be calculated, expressed in W/m2K.

Relative humidity This is the amount of water vapour inthe air relative to the amount the air can hold at the currenttemperature. Healthy relative humidity is generally regardedas being between 40% and 60%. High relative humiditycan lead to condensation, dampness and mould.

Seasonal performance factor The ratio of useful heatenergy output from a heat pump to the electrical energyinput (including compressor, circulation pumps and electricalimmersion, if present) averaged over an entire heatingseason.

Solar gain This refers to the heat energy that a buildingreceives passively from the sun, normally through its glazing.

Space heating demand The amount of active heatinginput required to heat a building usually expressed inkWh/m2/yr. It is often calculated using building energy softwareapplications such as PHPP, Deap or Sap.

Strip foundation A strip of concrete running under all ofa building's load bearing walls. This will normally includethe external walls, and possibly some of the internal walls.

Surface to volume ratio This is the total external surfacearea of a building relative to its volume. A lower surface tovolume ratio is generally more energy efficient, as it meansthere is less surface area from which heat can escape thebuilding.

Thermal bridging, alternatively known as cold bridging,occurs when heat or cold transfers across an external sur-face of a building. This can cause heat to escape from thebuilding or cold to enter. Thermal bridging occurs when athermally conductive material (ie a material with low re-sistance to heat flow) penetrates or bypasses the insulationlayer.

Thermostatic radiator valves are self-regulatingvalves, typically attached to radiators or other water heat-ing systems, used to control the room temperature auto-matically based on what temperature the TRVs are set at.

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 in-sulating. U-values are measured in watts per metre squaredkelvin (W/m2K).

Wall ties Material that bridges a wall cavity to join the innerand outer skins. They can be a point of thermal bridgingbut some modern wall ties are made from less thermallyconductive materials.

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.

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