Procedures C o r e Theme 4

Transcription

1 Authrs: Hans Erhrn Heike Erhrn Kluttig Prcedures C r e Theme 4 Nvember 2010 INTRODUCTION Reducing energy cnsumptin and eliminating wastage are amng the main gals f the Eurpean Unin (EU). They are embedded in Eurpe 2020 the EU's strategy fr smart, sustainable and inclusive grwth. EU supprt fr imprving energy efficiency will prve decisive fr cmpetitiveness, security f supply and fr meeting the cmmitments n climate change made under the Kyt Prtcl. There is significant ptential fr reducing cnsumptin. With 40% f energy cnsumed in buildings, the EU has intrduced legislatin t ensure that they cnsume less energy. A key part f this legislatin is the Energy Perfrmance f Buildings Directive (EPBD), which requires all EU Member States (MS) t tighten their building energy regulatins and t intrduce energy certificatin schemes fr buildings. All MS are als required t have inspectins f bilers and air cnditiners. The intrductin f natinal laws that meet EU requirements is challenging, as the legislatin has many advanced aspects. It is a great pprtunity t further energy efficiency in EU buildings, but als a frmidable and cntinuing challenge fr many EU Member States. T supprt them in this task, in 2005 the Cncerted Actin (CA) EPBD was launched by the Eurpean Cmmissin t prmte dialgue and exchange f best practice between them. An intensely active frum f natinal authrities frm 29 cuntries, it fcuses n finding cmmn appraches t the mst effective implementatin f this EU legislatin. The multi-faceted frmat f the frum, with specialist wrkshps cmbined with high level discussins, allied t netwrking pprtunities and web resurces, has centred n sharing -and inspiring- smart slutins nt nly fr the natinal legislatin and regulatins needed fr implementatin, but als fr the prfessinal tls, skills and systems in all fields addressed by it. These slutins are nw being applied acrss the majrity f EU Member States. The Cncerted Actin EPBD is carried ut under the crdinatin f ADENE, the Prtuguese Natinal Energy Agency The cnsrtium is cmpsed f rganisatins appinted by all 27 EU Member States, plus Nrway and Cratia 1

2 The activities revlve arund meetings, each with ver 100 participants, held apprximately twice a year Wrking grups and netwrking take place between meetings Only natinal authrities implementing the Directive are invlved, r thse bdies appinted and entrusted by the natinal authrities t d s Invited experts attend t give additinal specialist viewpints The 100+ Members f the CA EPBD represent Eurpe's authritative, cllective knwledge n practical implementatin and peratinal experience f energy perfrmance certificatin f buildings and inspectin and testing f bilers and air-cnditining systems. When initiated in 2005, mst MS were still at the planning stage, but are nw well advanced. After stimulating advancement and cnvergence acrss the EU, the CA apprach was further elabrated in The MS nw share real perating experience and the Cncerted Actin prvides ever increasing practical value and deeper learning t all participating authrities, playing its rle in ensuring the success f this Directive as a vital instrument f EU energy-efficiency plicy. The CA EPBD 2 ( ), the utcmes f which are presented in this bk, is rganised arund 5 Cre Themes (CTs): Certificatin f Buildings Inspectins f Bilers and Air-Cnditining systems Training f Experts Prcedures fr Characterisatin f Energy Perfrmance Infrmatin Campaigns Since its secnd phase was launched in December 2007, it has rganised six majr meetings between MS representatives, with intensive preparatry wrk in between. In additin t plenary sessins devted t issues f general interest, it rganised a ttal f 63 detailed technical sessins fr discussing specific issues relating t ne r mre f the 5 CTs. Sme sessins were rganised in cllabratin by tw r mre CTs, in tpics that had impacts n varius issues. The discussins built n the knwledge frm the eight previus meetings, held during the perid The initial plan fr the CA EPBD 2 included a lng list f tpics related t the varius Cre Themes and additinal tpics have been identified by the participants since its launch. A brainstrming sessin at the first meeting in December 2007 was very useful in defining the tpics f interest fr the MS t discuss in the cming years. Furthermre, the recast f the EPBD was launched and adpted during this perid, the CA being instrumental t that prcess. The secnd part f this bk cntains extended summaries f the main utcmes f each f the 5 Cre Themes, including cnclusins and recmmendatins. The bjective f the reprts n the Cre Theme activities is t present a snapsht f the cncerns and deliberatins f the teams dealing with practical implementatin f legislatin at natinal level. The synptic infrmatin presented in these thematic reprts is taken frm dialgue during the perid Sme tpics may nt have been revisited since the earlier part f that perid and, as such, the results may be representative f that pint in time. Nevertheless, the prs and cns f different appraches t implementatin f the Directive remain relevant. Fr details n the present situatin in all cuntries, i.e. in the final quarter f 2010, please see the Cuntry Reprts, part three f this bk. The CA EPBD is supprted by Intelligent Energy Eurpe under the Eurpean Unin's Cmpetitiveness and Innvatin Prgramme. 2

3 1 General Infrmatin Since its launching in December 2007, the Cncerted Actin (CA EPBD 2, ) rganised six majr meetings amng Member States' representatives, with intensive preparatry wrk in between. In additin t plenary sessins devted t issues f general interest t the 120+ participants in each meeting, it rganised a ttal f 63 detailed technical sessins fr discussing specific issues relating t ne r mre f the 5 Cre Themes (CTs), 29 f which were devted t tpics related t Methds and Prcedural Aspects fr Energy Perfrmance Characterisatin. Sme f these sessins were rganised in cllabratin with the ther CTs. As methds and prcedural aspects are the basis fr energy perfrmance assessment and certificatin f buildings, they have been f great interest frm the beginning f the Cncerted Actin in 2005; an average f mre than 40 participants jined these sessins. The initial plan f wrk included a lng list f tpics related t Prcedures; additinal tpics have been identified since then by the participants. A brainstrming sessin at the first meeting in December 2007 was very useful in defining the tpics f interest fr the Member States' representatives t discuss. A final review sessin was rganised in September 2010 and resulted in feedback that is als incrprated int this reprt. This reprt summarises the main utcmes f these Prcedures sessins, including cnclusins and recmmendatins. 2 Prgramme f Wrk The Cre Theme Prcedures wrks n tpics related t the Articles 3 t 6 f the EPBD (2002/91/EC). Accrding t the EPBD, Member States shall apply a methdlgy, at natinal r reginal level, f calculatin f the energy perfrmance f buildings. Based n this methdlgy, Member States shall take the necessary measures t ensure that minimum energy perfrmance requirements fr new and existing buildings that underg majr renvatin are set. The Eurpean Cmmissin has given t CEN 1 the mandate t develp a set f standards fr assessing the energy perfrmance f buildings. Due t the shrt time between the issuance f the mandate and the implementatin deadline, mst Member States further develped their wn natinal standards, as the CEN standards were still in the develping phase. Therefre, the methdlgies used in the Member States are differing greatly, including the use f calculated and measured energy perfrmance assessment. Thus, natinal minimum requirements dependent n the methdlgies cannt easily be cmpared amng the Member States. 3 Activities under the Prcedures Theme The activities included many aspects f the develpment f prcedures, their practical applicatin and verificatin, as well as the Eurpean activities n harmnisatin. The mst imprtant tpics discussed during the CA EPBD 2 are listed belw: High perfrmance buildings Definitins Occurrence Natinal radmaps Lw-energy buildings in Suthern Eurpean climates Cmparisn f natinal requirements Setting minimum energy perfrmance requirements Cst-benefit assessment methds 1 Eurpean Cmmittee fr Standardizatin 3

4 Natinal prcedures Cst-ptimal framewrk f the EPBD recast Minimum requirements fr technical systems State f the art CEN cmpatibility Advances Sftware applicatins Changes in natinal prcedures after the implementatin f the EPBD (status 2010) Measured energy perfrmance rating Prcedures Benchmarks Parallel use f calculated and measured energy rating Feasibility analysis f alternative systems Prcedures fr specific certificatin challenges Special issues Recmmendatins Cmplex buildings Thermal bridges Infrared thermgraphy Climatic crrectin factr with fcus n cling Sme f the tpics were arranged in cperatin with the ther Cre Themes and are therefre als described in their relevant chapters. These tpics are described frm the pint f view f the respective Cre Theme. 3.1 High perfrmance buildings High perfrmance buildings cnstitute a grwing part f the Eurpean building stck; 2/3 f the Eurpean Member States include them in natinal radmaps as the gal fr future new buildings. Varius terms fr high perfrmance buildings are used in the cuntries. By cmparing the definitins r the calculatin prcedures f the building types, it became clear that fr many terms n real definitin exists, and fr mst thers the definitins differ amng cuntries. - Biclimatic Huse - Passive huse - BREEAM Building - Plus Energy Huse - Carbn Free Huse - TBQ: Ttal Quality Planning and rating - Climate: Active Huse - Triple Zer Huse - CSH: Cde fr Sustainable Hmes - Ultra Lw energy Huse - Ec-Building - Very Lw Energy Huse - Emissin Free Huse - Zer Carbn huse - Energy Saving Huse - Zer Emissin Huse - Energy Self-Sufficient Huse / Energy Autark Huse - Zer Energy Huse - Green building - Zer Heating Energy Huse - Lider A Liter Huse - Lw Energy Huse Figure 1. List f identified terms fr high perfrmance buildings used in the EU Member States. Additinally, special attentin has been devted t lw-energy slutins fr Suthern Eurpean climates, where cling becmes much mre imprtant. 4

5 3.1.1 Main cnclusins At the time f the enquiry, in spring 2008, 23 different terms fr high perfrmance buildings were identified acrss Eurpe. There is a strng need fr the harmnisatin f terms and definitins, and als fr the assessment f existing definitins in cmparisn with the fficial calculatin methds. Market cnfusin needs t be avided thrugh, e.g., parallel certificatin. The definitins f high perfrmance buildings shuld nt limit the technlgical ptins which can be used t meet perfrmance requirements. The existing definitins are ften nt based n natinal calculatin prcedures, and the buildings can therefre nt easily be cmpared with the EPBD rating. All cuntries stated that examples f ne r mre high perfrmance building types have been realised in practice within the cuntry. Tw thirds f the cuntries have a natinal radmap that includes ne r mre types f high perfrmance buildings as the gal fr future new buildings. Seven f eight cuntries f Suthern Eurpe that respnded t a questinnaire reprted that there exists n natinal definitin fr a lw-energy building. The minimum requirements used fcus nly n the envelpe and shading; verall requirements r requirements fr technical systems are missing. Hwever, a minimum fractin f slar energy fr dmestic ht water is prescribed in the building regulatins f many cuntries f Suthern Eurpe Future directins The next steps n the way twards harmnising the terms and definitins can be: 1. A cmparisn f the definitins f high perfrmance buildings with the natinal EPBD calculatin and the resulting certificatin labels. Are all high perfrmance buildings really class A buildings? 2. A clarificatin f the terms and definitins, as well as a disseminatin f the knwledge t the building prfessinals, the public (building wners) and, last but nt least, t natinal and internatinal plicy makers. 3. A review f natinal funding plicies fr high perfrmance buildings. 4. A review f the natinal radmaps, cncerning the realisatin f the planned gals fr buildings. What are the necessary steps in rder t secure a smth transfer f natinal requirements until the high gals are reached, what csts will result frm it, and is the industry able t prvide the necessary technlgies and strategies? 5. Fcused effrts t help the smther implementatin f lw-energy buildings (nearly zer-energy buildings) in Suthern Eurpe. There is a strng need fr the harmnisatin f terms and definitins f high perfrmance buildings. These definitins, hwever, shuld nt limit the technical ptins and innvatins. Parallel certificatin schemes fr high perfrmance buildings (in cmparisn with natinal energy perfrmance certificatin) result in market cnfusin; this needs t be abslutely avided. The market penetratin f high perfrmance buildings in Suthern Eurpean cuntries is significantly lwer than that in Middle and Nrthern Eurpean cuntries. In rder t meet the EPBD recast target f nearly zer-energy buildings by 2020, mst Suthern Eurpean Member States will have t bridge a larger gap. 3.2 Cmparisn f natinal requirements During the perid , the CA participants discussed five different studies n the intercmparisn f natinal energy perfrmance requirements, mstly between neighburing cuntries. All studies have been used as a preparatin fr a tightening f natinal requirements. Additinally, the IEE prject ASIEPI 2 2 ASIEPI Intelligent Energy Eurpe - Prject number EIE/07/169 Assessment and imprvement f the EPBD impact (fr new buildings and building renvatin) 5

6 presented the develped cncept fr cmparing natinal requirements. The discussins were rather lively, and fcused n the methdlgies that were chsen fr the cmparisn f the different requirements; they als fcused n the influence parameters which have been analysed in different depths within the studies. Als, the way in which the results were presented was disputed. The main discussin pints can be summarised as fllws: An intercmparisn study includes s many different influence parameters, that it may never be a fair and rbust cmparisn f natinal energy perfrmance requirements. Influence parameters include climate data, natinal calculatin prcedures, natinal default values and chices that have t be made during calculatin, building traditin, used and allwed building system cnfiguratin in the cuntries, detailed assessed energy parts in the calculatin methd (energy needs, energy use, primary energy), natinal primary energy factrs r CO 2 - factrs, values fr building system perfrmances used in natinal calculatin prcedures, airtightness values and thermal bridges values, slar shading factrs, internal gains and usage times, set rm temperatures, different calculatin methds fr flr and building cmpnent areas and vlumes (internal r external dimensins, etc.), etc. It is nt apprpriate t present the results f an intercmparisn study by reducing it t required U-values, as it takes away the influence f the building systems. Eurpe has already made the step frm U-value requirements t primary energy perfrmance r CO 2 emissin requirements within a hlistic, integrated apprach. It is necessary t use mre than ne basic building fr a cmplete verview. Different building types and different building systems will prbably make the verview mre cmplex, but als mre crrect. The methdlgy f sme f the studies was partly influenced by the expected results. The ffered natinal incentives might rund-up the verview f natinal requirements If intercmparisn studies als include cst influences, the experts having perfrmed r initiated these studies s far are afraid that this will becme even mre cmplicated. It is unclear whether it will ever be pssible t find a fair scientific cmparisn. A glbal cmparisn may be pssible, but fair and rbust? A further prblem is that natinal requirement levels and calculatin prcedures are changed s ften. Thus, any intercmparisn study can nly be a 'snapsht', an verview f the actual situatin, which might be ut-dated even befre the cmparisn has been finalised. Mst f the intercmparisn studies, hwever, did have an influence n the natinal energy perfrmance requirements f the cuntry that initiated the study. The results gave arguments fr a tightening f the requirements, as ther cuntries seemed t have mre severe requirements. The wrk in the IEE ASIEPI prject did nt nly shw hw difficult an intercmparisn study is. It als pinted ut hw many influence parameters have t be taken int accunt, and gave a first impressin f hw big the influence f different parameters is. Figure 2. Presentatin slide illustrating the challenges fr the cmparisn f energy perfrmance requirements in different Member States by using a cmparisn between tw fruit baskets. 6

7 3.2.1 Main cnclusins Experiences frm the studies shwed that intercmparisns are influenced by many different parameters, including natinal calculatin prcedures, bundary cnditins like user behaviur, the climate, the used base case technlgies, building types and building gemetry, and even simple issues like the definitin f the reference flr area. There is currently n rbust, simple and fair methd available fr the cmparisn f different natinal requirements. The participants pinted ut that the situatin might get even mre cmplicated if cst assessment is added t the cmparisn. The studies shuld include the ptential impact f the varius influence parameters Future directins The IEE ASIEPI prject has cmpleted its wrk regarding the cmparisn f natinal requirements, and has develped and tested a cnceptual methdlgy fr such cmparisn studies. All prject results are presented n and Sme tpics still need further discussin, such as: Weather crrectin fr calculated and measured energy perfrmance, with special regard t cling. Natinal studies fr cst-ptimal minimum energy perfrmance requirements. There is currently n rbust, simple and fair methd available fr the cmparisn f natinal requirements. The situatin might get even mre cmplicated if cst assessment is added t the cmparisn. 3.3 Setting minimum energy perfrmance requirements In rder t imprve the understanding f hw Member States chse the levels f minimum energy perfrmance requirements, discussins fcused n three different issues: Types and basic principles f cst-benefit assessments. Methdlgy fr the cst-ptimum calculatin f natinal requirements as defined in the EPBD recast. Minimum requirements fr building service systems. The instruments f energy plicy may be assessed frm a variety f perspectives. Fr minimum energy perfrmance requirements fr buildings (fr brevity ften referred t as building energy cdes r building energy regulatins ), the mst relevant are: Ecnmic: t assess csts and benefits t sciety. These may include csts and benefits that are nt adequately reflected in the market prices. The mst bviusly relevant f these is the expected cst t sciety f the climate change resulting frm greenhuse gas emissins. The fcus fr this type f assessment is cst-effectiveness seen frm the perspective f sciety as a whle. Financial: t assess csts and benefits frm the perspective f an ecnmically ratinal purchaser. The measures that seem t be financially wrthwhile n the basis f ratinal financial assessment, but are nt actually taken up, are an established feature f building energy efficiency. Here, the issue is the cst-effectiveness frm the perspective f building wners and their agents r prxies. Accelerated technical develpment: t assess the value and cst f an increased rate f develpment and implementatin f relevant nvel technlgies. This culd be justified frm either an ecnmic r a financial perspective but, in either case, there are likely t be cnsiderable uncertainties f csts and benefits. Tw cmmn errrs in cst-effectiveness assessments f energy saving measures need t be guarded against: the bundling f different measures int single packages, and the chice f inapprpriate baselines. 7

8 Mst Member States already carry ut either financial r ecnmic cst-effectiveness calculatins in supprt f the requirements. Many d bth. A significant minrity reprted that they d nt use such methds. Accrding t Article 5 f the EPBD recast, the Eurpean Cmmissin shall establish a cmparative methdlgy framewrk fr calculating cst-ptimal levels f minimum energy perfrmance requirements fr buildings and building elements. The Cmmissin presented as a first draft the pssible key steps f this framewrk methdlgy t be: Selectin f reference buildings. Definitin f energy efficiency packages (i.e. sets f measures). Calculatin f the energy use f a building r building element. Cst calculatin accrding t the net present value, which includes the glbal cst calculatin, the definitin f the calculatin perid, the definitin f input parameters fr the cst calculatin, and a sensitivity analysis. Many Member States already apply prcesses similar in nature and purpse t thse presented. Others are at an early stage f applying cst-effectiveness calculatins t the building energy perfrmance standards. Therefre, the ideal utcme wuld be a prcess that is simple yet rbust, while als being as cnsistent as pssible with the existing established prcedures. Ideally, it shuld have sufficient flexibility t accmmdate the established prcedures and t be cnsidered by the Member States as an acceptable cmprmise between cmplexity and rigr. In additin t minimum energy perfrmance requirements n the building level and pssibly n the building envelpe, mst Member States have set requirements fr building service systems. Thse requirements vary in detail (whle system r cmpnent level) and rate f use in the cuntries. The minimum requirements f the technical building systems and lighting elements are cvered by the 2005/32/EC, 2010/30/EU Ecdesign and Eclabel Directives. Als, the 2010/31/EU EPBD recast requires Member States t set requirements fr the system. It remains t be seen exactly hw verall system requirements will be defined, as they are dependent n the interactin f varius cmpnents f the building Main cnclusins Cst-benefit assessments fr setting requirements can be perfrmed frm different perspectives. Mst Member States are already fixing their requirements based n either financial r ecnmic csteffectiveness calculatins. Many fllw a prcedure similar t the planned methdlgy fr the cstptimum assessment f the EPBD recast. The ideal utcme wuld therefre be a prcess that is simple yet rbust, while als being as cnsistent as pssible with the existing established prcedures Future directins Cncerning the verall building service system requirements, the interface between prduct perfrmance infrmatin and system perfrmance calculatin seems wrthy f further investigatin, cncerning, in particular, prduct infrmatin, such as part lad efficiency, t be used in EPBD calculatins. The cst-ptimum methdlgy shuld be simple yet rbust, while als being as cnsistent as pssible with the established prcedures in the Member States. 3.4 Natinal prcedures Currently applied natinal prcedures, as well as the timing and cntent f further develpments, have been described and cmpared. This included a reflectin in 2010 n changes in natinal prcedures after the implementatin f the EPBD in several Member States. In-depth discussins have als been held n the set f standards prepared under the Eurpean Cmmissin's mandate t CEN t supprt the EPBD. These 8

9 standards were mstly published in the years There was a detailed discussin n whether the CEN standards are taken int accunt by the natinal prcedures -and n hw this is dne-, and a dialgue was als maintained with the participants f the IEE prject CENSE 3. The result was that there is n cuntry that uses a ne-t-ne transfer f all CEN standards int their prcedures, but many cuntries use a CEN cmpatible apprach. Many reasns were given fr nt using the CEN standards mre extensively: Difficulty f cnverting int practical prcedures: CEN standards include alternative paths. Natinal prcedures mstly fix ne path. Incnvenient structure: CEN requests t include the natinal bundary cnditins as an annex. Cuntries prefer t have the bundary cnditins integrated in the standard. Therefre, a natinal standard is written, which takes the CEN elements int accunt, but is n lnger a CEN standard. Timing: Implementatin decisins had t be made befre standards were available. Cpyright f CEN standards: Sme cuntries insist that natinal prcedures shuld be available fr free. Sme CEN standards d nt cver the whle challenge f the EPBD. An example fr this is the lighting standard EN 15193, which is applicable fr existing buildings, but nt fr the building design phase. The cuntries needed t develp their wn methd fr this. The CEN prcedures may frm a barrier fr swift natinal respnses t mvements r pprtunities in the market. In sme Member States, the building cde writers are nt invlved in CEN standards writing. Other cnclusins frm the discussins are: There is a need fr a simplificatin f the standards, thugh that applies mre t the data requirements than t the calculatin methds. Sme standards are unsuitable fr existing buildings, where the need fr simple, practical and csteffective methds is paramunt. The Energy using Prducts Directive, the Envirnmental Liability Directive, and pssibly ther directives, intrduce requirements fr perfrmance testing f energy-using prducts. Where such prducts are installed within buildings the results are relevant t the EPBD calculatins and shuld be allwed fr in the standard methds. The fllwing remarks and suggestins t CEN have been wrked ut: A technical review f each standard is needed, in terms f scpe and relevance, identifying any gaps r verlaps, as well as incnsistencies. In rder t avid ambiguities, and fr a mre efficient use f the standards, it is recmmended that CEN leaves n lse ends in the prcedures: fr each variable, it shuld be made clear whether the input is expected frm anther equatin, frm anther standard r t be prvided natinally. Calculatin results shuld be cnfirmed in terms f prducing realistic results. It wuld als imprve the transparency f the calculatin prcedures if all standards had a similar structure, distinguishing general prcedures, specific detailed prcedures (e.g. allwing fr natinal ptins), as well as (e.g. partly natinal) input and bundary cnditins. The Member States are mst interested in a harmnised framewrk (methdlgy) that allws natinal differentiatin. Standards shuld be distinguished frm cmplementary guidebks. The planning f the future steps f CEN and ISO shuld be transparently cmmunicated. Revised standards shuld be tested against acceptance criteria set by a Liaisn Cmmittee, 3 CENSE Intelligent Energy Eurpe - Prject number EIE/07/069 Leading the CEN standards n energy perfrmance f buildings t practice Twards effective supprt f the EPBD implementatin and acceleratin in the EU Member States 9

10 representing the EPBD implementing bdies, befre prceeding t the vting stage. In the future, the standards will be mainly applied by cmputer sftware. Standards writers shuld have this in mind. The abve recmmendatins were presented in brief t the Eurpean Cmmissin and CEN in a meeting hsted in May 2010 by the Directrate General fr Energy. They were cmmunicated in detail t bth parties, and were instrumental in shaping the Cmmissin's mandate fr the 2 nd generatin f CEN EPBD standards. Figure 3. Diagram presenting the analysed perid f changes in natinal EPB prcedures. In 12 f the 24 cuntries respnding t a survey carried ut in 2010, changes in the EP prcedures have been already realised since the first natinal implementatin f the EPBD. Nearly all f thse cuntries which made changes have tightened their EP requirements (10 ut f 12 cuntries). Furthermre, 7 cuntries reprted that, due t the changes, the new prcedure is CEN cnfrm. Different appraches t the summer cmfrt estimatin and the cling demand calculatins are used in the EU Member States. A wrking grup has analysed the requirements fr, e.g., the calculatin time step and the zning f buildings in the Member States calculatin prcedure, based n a frm filled by the Member States. It was clear frm the discussin at the meeting that n Member States believed r claimed that they have already fund the right r best balance in the ptimisatin f time-cst-accuracy related t their cling demand calculatin prcedure. Calculatins can be dne using the standard EN ISO 13790: mnthly calculatin simplified hurly apprach Different appraches n minimum requirements fr summer thermal cnditins are used in the cuntries (temperatures nt higher than X C in Y % f ccupancy time; temperatures lwer than X C in Y % f time). The cuntries are cncerned abut time cnsumptin, cmplexity and feedback frm practice if they require t much f the calculatin prcedure regarding zning fr the calculatin f summer cnditins and cling demand. 10

11 Figure 4. Cmparisn between the cling demands f a 1-zne mdel and a 2-zne mdel calculatin fr a sample ffice with heavy cnstructins situated in Würzburg, Germany. The rientatin f the facades was nrth-suth. Windws: Uw = 1.4 W/(m²K), g = 0.6, f F = 20 %. Active sun prtectin. Internal lads 0 W/m². Cling if Ti > 24 C. The windw fractin (f W ) was varied. Mst natinal prcedures are applied as sftware prgrammes. The discussins n the available sftware cncentrated n quality cntrl and accreditatin, as well as n the necessary level f input data fr assessing the summer perfrmance, especially whether multiple znes are necessary. One-zne mdels can be prblematic fr summer cmfrt and cling, as they underestimate the cling demand and the verheating perid. Figure 4 shws that there is a cnsiderable difference between the cling demand in a 1-zne mdel and a 2-zne mdel. Als, it is evident that the 1-zne mdel is nt n the safe side, as it prduces a lwer cling demand instead f a higher cling demand. Multi-zne mdels slve these prblems, but require increased effrts and may need simplificatins. Many cuntries, but by n means all, are using the EN mnthly calculatin prcedure. Hwever, it des nt cver HVAC r lighting systems. The EN testing prcedure is nt intended fr mnthly calculatin methds (althugh the EN mnthly methd is understd t meet the cnsumptin requirements at the lwest level f acceptance). Fur f the nine cuntries respnding t a questinnaire indicated that accreditatin measures fr sftware tls were in use r planned. Of these, mst included the use f sample buildings. Pssible further actins cncerning the quality cntrl f sftware applicatins are: Agreement n principles fr a suite f sample buildings. Filling f gaps in accreditatin tests. Recmmendatins fr the reprting f intermediate calculatin values. Sharing experience frm beta-testing and live applicatin f sftware. Define a scpe fr EU-wide standards test prcedures r certificatin rutes. There is n cuntry that uses a ne-t-ne transfer f all CEN standards int their prcedures, but many cuntries use a CEN-cmpatible apprach. Mst natinal prcedures are applied as sftware prgrammes. Hwever, sftware accreditatin seems t be cnducted in nly abut half f the Member States. There is n best slutin s far fr the ptimisatin f time cst accuracy related t the cling demand calculatin. 11

12 In 50 % f the cuntries respnding t a questinnaire, changes in the EP prcedures have been already realised after the implementatin f the EPBD. The implemented changes are rather diverse, having, hwever, sme general directins: - tightening f requirements - cnfrmity t r direct use f the CEN standards - crrectin f weaknesses/gaps in the earlier EPBD implementatin prcedures - inclusin f additinal technlgies 3.5 Measured energy perfrmance rating Several Member States allw measured energy perfrmance rating fr existing buildings. There is a need fr a simplificatin f the certificatin prcedures and measured energy perfrmance is perceived as a way t save effrts and mney. The cuntries are mstly aware f the advantages f measured energy rating, but are ften nt aware f all the risks arising frm it. There is n cmmn methd, neither fr the nrmalisatin f measured energy and fr the check f the data quality nr fr ways fr dividing the measured energy int different uses. Additinal infrmatin n the use f measured energy perfrmance rating can be fund in the Cre Theme 1 Certificatin reprt. Different systems fr the benchmarking f measured energy rating exist in the Member States. In rder t further develp these systems, sme cuntries need t find mre benchmarks and/r mre subcategries, whereas ther cuntries plan t reduce the number f subcategries in rder t facilitate the rating. Mst cuntries answering the questinnaire n measured energy perfrmance use r intend t use the measured energy rating at least fr sme types f building and at least fr sme purpses. Its use is nt nly fr certificatin, but als fr preliminary diagnsis, energy saving recmmendatin r additinal infrmatin in the certificatin prcess. The building categries cvered r intended t be cvered by measured rating are mstly public buildings, but als apartment blcks. In sme cuntries, family huses are als invlved in measured energy rating, but the way f handling the influence f the inhabitants' behaviur in small buildings with ne user was nt explained. The cuntries mstly have n experience with measured energy perfrmance rating, and the existing natinal methds are rather simplified. In 7 cuntries, a natinal standard r guideline n measured energy rating ther than the EN is used. Only in few cuntries the natinal methd fr measured energy rating cmplies with the EN 15603, and n cuntry has created a natinal annex t the EN There is a need fr an amendment f the EN 15603, t better supprt measured energy rating. Sme cuntries prefer t imprve their natinal methd fr measured energy rating. In terms f nrmalisatin, nly few cuntries take int cnsideratin internal heat gains, internal temperature and ventilatin rate. In sme cuntries (4), measured energy rating is a part f the energy perfrmance certificatin scheme r f the preliminary energy diagnsis, but n nrmalisatin f measured energy is identified and used. Sme cuntries have special requirements fr data quality (7), but these are mstly based n recmmendatin, nt set at legal basis. The prblem f hw t divide the measured energy int different uses is slved in a very simplistic way. In sme cuntries, all energy is included (7), r separate measurement per use is required fr the measured energy rating. The CA wrked t identify prcedures and best practice n benchmarking systems, and t give a basis fr the imprvement f (existing) systems. Many Member States have initiated a benchmarking system t analyse the energy cnsumptin f the building stck. Sme Member States have initiated a benchmarking system with gd infrmatin n the energy cnsumptin f the building stck, and sme thers with limited infrmatin. Hwever, benchmarks were created n the basis f -r partly n the basis fstatistical data; the benchmarks were fund by calculating an average value. In sme cases, a system was nt develped, but an already existing system was adpted. Many benchmarking systems are based n the final energy cnsumptin, and cver the verall result f the energy used fr heating, ht water, cling, ventilatin and built-in lightning. The energy cnsumptin fr heating and electricity is ften treated by at least tw numeric indicatrs, and in sme cases by ne cmbined numeric indicatr. A typical difference in the benchmarking systems f the Member States is the number f different categries f benchmarks that are taken int accunt. The numbers f benchmarks range frm less than five t even mre than 30. Often, the categries are identical r almst identical t 12

13 thse in the annex f the EPBD. In ne case, the benchmarking system was develped n the basis f custmised benchmarks. The apprach fr the generatin f the reference values takes int accunt the actual use f the building (the building is divided int znes), the use f mechanical ventilatin and cling, as well as special uses like IT, elevatrs r kitchens. Prs n benchmarking systems are: In rder t build up a benchmarking system, it is nt necessary t have detailed infrmatin n the energy cnsumptin f the building stck. It is gd enugh t have a partial knwledge abut the building stck energy cnsumptin, based n statistical data. Sme Member States already had infrmatin n the building stck energy cnsumptin, based n statistical data, befre develping a benchmarking system. Sme Member States used r partly used an already existing system. Cns n benchmarking systems are: The need fr a kind f statistical basis f the building stck energy cnsumptin is cmmn in all benchmarking systems. This data must be cllected and analysed. The statistical analysis f the energy cnsumptin f the building stck in rder t get a benchmark usually leads t a typical/average energy efficiency level f benchmarks. Best practice/very gd energy efficiency levels f benchmarks are nly used in tw Member States. The need fr sme kind f imprvement after a certain time perid r while experiences are gathered is cmmn in many benchmarking systems f the Member States. In rder t imprve the existing benchmarking systems, it is necessary t: either find mre benchmarks r t reduce the number f benchmarks (depending n the cuntry's apprach) either find mre subcategries r t reduce the number f subcategries (depending n the cuntry's apprach) Sme f the experiences f the Member States related t creating and imprving a benchmarking system have a general character and can be transferred t ther systems. In rder t have a functinal benchmarking system, it is necessary t have benchmarks that cver: Typical building categries f a Member State. T achieve this, the building stck must be analysed and described in a building-typlgy. Typical sizes f buildings. The benchmark f a specific building categry smetimes varies depending n the buildings' size. Fr this reasn, in sme building categries there can be a differentiatin between smaller and bigger buildings. Typical subcategries in terms f use. Depending n the building stck, it may be necessary t take int accunt typical subcategries such as: Schls: elementary schls, secndary schls etc. Administrative buildings: ministries, public ffice buildings, general ffice buildings, bank buildings etc. Typical technical standards. Depending n the building stck, it may be necessary t take int accunt typical technical standards, such as natural ventilated r air-cnditined. Many buildings have mixed uses, such as an ffice building with a restaurant, and are nt cvered by the benchmarks themselves. In this case, a mixture f tw benchmarks (ne benchmark fr ffice buildings and ne fr restaurants) can be calculated fr these buildings frm the benchmarks fr the different uses, weighted by the flr area f each use. A typical apprach fr imprving a system in the Member States is t gather experience with a certain system and t update the benchmarks when mre statistics and experiences are available. The typical prblems are: Finding a reliable data surce. Finding a representative number f cnsumptin data fr each building type. The quality f cnsumptin data is ften pr. 13

14 The parallel use f calculated and measured energy rating was als discussed. Only very few cuntries use bth rating systems in parallel, and they reprted n their experiences. Differences in the ratings result mstly frm different user behaviur in practice, cmpared with the standard user prfiles in the calculatins Main cnclusins: The mst imprtant aspects actually cnsidered and taken int accunt fr the nrmalisatin f measured energy perfrmance identified frm the questinnaires are: Climate Building size Building type, clsely cnnected with hurs f peratin and pattern f use Future directins: T handle the prblems cncerning the benchmarks fr measured energy perfrmance, a high quality database-management is needed. Special attentin shuld be given t: Requirements fr the quality f the data used fr measured energy rating and benchmarking. Nrmalisatin prcedures, including weather crrectin prcedures. Divisin f measured energy int different usages, and exclusin f thse energy uses that are nt part f the EPBD prcedure. Ways t derive recmmendatins fr imprvements, based n measured energy rating. The cuntries are mstly aware f the advantage f measured energy rating, but are ften nt aware f all the risks arising frm it. A cmmn methd fr the nrmalisatin f measured energy is missing as well as data quality checking prcedures and ways fr dividing the measured energy int different uses. Sme cuntries plan t add mre benchmarks and/r mre subcategries, whereas ther cuntries plan t reduce them, in rder t facilitate the rating prcedures. 3.6 Feasibility analysis f alternative energy systems The feasibility study requirement is transpsed int the natinal legislatin f the 27 EU Member States in varius ways. It is nt clear in every case neither hw the quality f the feasibility study is guaranteed nr wh is respnsible fr the cntrl. Thus, it will nt be easy t have a Eurpean-wide standardisatin f the prcedure and the cmpliance f the requirement. The IEE prject SENTRO 4 has develped a handbk, as well as supprting tls, like checklists, etc., that shall help t standardise the prcess. Withut a prper cmpliance system in place, the feasibility study requirement pses the risk that the calculatins/reprts are made indeed, but there will nt be much impact in practice. The key factr in the whle prcess is the timing f the feasibility study: it has t be carried ut in the pre-design phase, when the strategic decisins are being made. 4 SENTRO Intelligent Energy Eurpe - Prject number EIE/06/102 Sustainable energy systems in new buildings Market intrductin f feasibility studies under the Directive n Energy Perfrmance f Buildings 14

15 Building prcess Utility building SENTRO develped supprt tls Planning Prgramming Agreement n starting pints Request fr feasibility study First shift f energy cncepts Building prgramme Feasibility study: twards 2 t 3 energy cncepts Checklist Handbk: gd practice examples, answers t frequently met bstacles Prpsal Prject Preliminary design Feasibility study: tune in n final energy cncept Final design Engineering installatin details f final energy cncept Checklist Handbk: Outline t take int accunt technical, financial, rganisatinal and envirnmental aspects Building permit Tendering Preperatin Cnstructin Operatin Specificatins Qualificatins Cnstructin drawings Cnstructin Cmpletin and Use Surce: TNO, Van Kervel 2006; additins energy cncepts by Ecfys Space t find suitable slutins t realise a high quality building, including an ptimal energy cncept within acceptable csts Figure 5. Space fr suitable slutins fr the realisatin f a high quality building, including the ptimal energy cncept and the develped supprt tls, taking int cnsideratin alternative energy systems Main utcmes: The feasibility study requirement (Article 5 f the EPBD) is transpsed int the natinal legislatin f 27 EU Member States in varius ways. This implies that it will nt be easy t have a Eurpeanwide standardisatin f the prcedure and cmpliance with the requirement. The apprach develped within SENTRO, including its supprting tls, is an initiative twards standardisatin. In particular, the handbk is a prtcl: it specifies hw t perfrm a highquality feasibility study f alternative energy systems in buildings Future directins: Mre attentin is needed t be paid t the assurance f the quality f perfrmed feasibility studies f alternative energy systems, as well as t the assurance f cmpliance. The key factr in the whle prcess is the timing f the feasibility study, which has t be carried ut in the pre-design phase, when the strategic decisins are being made. 15

16 3.7 Prcedures fr specific certificatin challenges Recmmendatins fr energy imprvements f existing buildings are derived in different ways in the Member States, inter alia: The use f either calculated r measured energy rating. Standard recmmendatins t chse frm, r individual recmmendatins made by the issuer. Inclusin f energy and/r cst data. Natinal sftware that prpses recmmendatins autmatically. Natinal presentatins ffered the chance fr exchanging practical ideas n hw t develp suitable recmmendatins. A special challenge seems t be the quantificatin f recmmendatins when using measured energy rating. Indicatin f the ptential energy savings are handled very differently in the Member States. In sme cuntries, energy savings are being recalculated t cst savings, while mst cuntries display energy savings. The energy savings, hwever, are nt given identically in all cuntries, but variusly, in differing cmbinatins: Ttal and/r specific primary energy need. Ttal carbn r equivalent CO 2 emissins. Ttal and/r specific final energy cnsumptin. Ttal saved delivered energy, primary energy and CO 2 -emissin, als % f thse. List f measures nly accrding t payback, withut values. Actual cnsumptin and cnsumptin estimated after refurbishment, Als, the ecnmic presentatin f the energy savings is given very differently: Currency/saved kwh f final r primary energy. Energy cst fr husing, with sme sftware fr ther buildings. Investment csts and payback perid. Reductin f energy csts after refurbishment. The number and quality f the recmmendatins given in the certificate is strngly dependent n the certifier and/r the sftware tl being used. Natinal recmmendatins r rules may apply. Figure 6 shws an verview f the restrictins, in terms f the number f recmmendatins in the different certificates. Fr cmplex buildings, the energy certificatin is nt an easy task, because f a difficult gemetry, a lt f technical installatins, ften pr dcumentatin f building cmpnents, etc. Als, the mixed use f a building (e.g., a cmmercial/residential building with shps in the grund flr and flats in the upper flrs) can cmplicate the certificatin prcess. The fllwing prblems emerge with cmplex buildings: In case f calculated rating: availability f data surces, identificatin f technical systems, calculatin prcedures and zning rules. In case f measured rating: availability and assignment f metres, quality f reference values, different users r change f user. After the discussins, the Member States participants agreed t sme recmmendatins: Fr calculatins, a reduced zne mdel shuld be cnsidered. Measurements shuld be supprted by guidelines fr the installatin f metres and fr in situ measurements. Benchmark prcedures shuld include a variety f uses and rules fr creating benchmarks fr buildings with mixed use. 16

17 Q2: Is there a general list f pssibly recmmended energy saving measures? Number f cuntries [ - ] yes n yes, but certifier can add measures thers (please specify) Figure 6. Overview f the answers t the questin n hw recmmendatins are derived in different Member States. The survey was made at the end f Recmmendatins prvided in the certificate shuld be directly targeted t the actual building being certified. This will increase public acceptance f the certificate and help persuade building wners t implement the suggested energy saving measures. Fr large and cmplex buildings, it seems apprpriate t use measured energy perfrmance values. Then, guidelines fr installatins f metres and sub-metres are needed, as well as guidelines fr in situ measurements. 3.8 Special issues Accrding t an analysis in IEE ASIEPI, cuntries cver thermal bridges in different ways in their natinal EPBD implementatin, regarding energy impact, limits, gd practice guidance, as well as cmpliance checks at the design and realisatin phase f a building. This analysis was mirrred, extended and discussed in the CA. Thermal bridges becme even mre imprtant fr high perfrmance buildings, as the relative impact f prly designed cmpnent jints n the heating energy cnsumptin can be significant. The main discussin pints and cnclusins n thermal bridges can be summarised as fllws: Mst cuntries stated that they include thermal bridges in the energy perfrmance calculatin fr new buildings, r, as it happens in tw suthern cuntries, they are in the prcess f including thermal bridge influences in their calculatins. Sme cuntries d nt include thermal bridges in the energy perfrmance calculatins fr the renvatin f buildings. Cmpliance and cntrl: abut half f the cuntries cnduct a cntrl during r after the design phase. A few cuntries cnduct a cntrl during the realisatin phase. Thermal bridges are checked differently during design and realisatin: One cuntry requires that all details with a pssibility f cndensatin have t be sent t the authrities fr a check. A secnd cuntry reprted that the detailed design has t be submitted fr the building permit and that the U-values fr cmpnents and the crner jints, etc. are checked by the authrity. 17

18 Anther cuntry perfrms a general check in cnnectin with the building permit. The respnsibility lies generally with the building wner, but in a few cuntries they can hand it ver t the designers. Are the checks in the cuntries perfrmed as a standard rutine, r is this just a general pssibility which is rarely realised? This seems t be quite different in the varius cuntries. It was reprted that the executin check is nt exercised n a regular basis in mst f the cuntries that stated that this prcedure des exist. Is there really a significant impact f thermal bridges n the cling lad f buildings? While there was cnsensus that thermal bridges have n influence n the cling energy, the currently available results regarding the impact f thermal bridges n the cling lad are incnclusive and further research is needed. Sme f the Suthern Eurpean experts were surprised that there seems t be an impact n the cling lad. Tw cuntries have cnducted studies n the impact f the paque building cmpnents n cling issues, and have fund that nly the rf has sme impact. Hwever, they have nt analysed the thermal bridges in detail. Figure 7. Interactive wrkshp during the sessin n the handling f thermal bridges in the EPBD cntext Main cnclusins: The cllectin f infrmatin n natinal appraches fr including thermal bridges in the energy perfrmance regulatins, n useful and validated sftware, n thermal bridge atlases, as well as n gd practice guidance and innvative develpments in this field, cmbined with the presentatin in infrmatin papers and ther disseminatin activities was cnsidered as very valuable wrk. All infrmatin gathered is available at and Mst cuntries take thermal bridges int accunt fr the energy perfrmance calculatin f new buildings, and less fr the renvatin f existing buildings. The cmpliance and cntrl checks during the design and realisatin phases seem t be handled n diverse levels varying nt nly amng the cuntries, but als within a cuntry, amng different regins. It was agreed that the issue f thermal bridges is even mre imprtant fr high perfrmance buildings, as the relative impact f prly develped and executed jints can becme significant and reach the same level f significance as, fr example, the additin f a slar thermal system fr dmestic ht water Future directins The assessment f thermal bridges needs t be further discussed, twards finding mre cmmn slutins fr all Member States. Infrmatin n thermal bridges is available at the BUILD UP cmmunity "Thermal Bridges Frum, The cmmunity als ffers a discussin platfrm fr specific items. 18

19 Thermal bridges becme even mre imprtant fr high perfrmance buildings. Cuntries cver the issue f thermal bridges in different ways. The impact f thermal bridges n the energy perfrmance is even mre imprtant fr high perfrmance buildings: energy wastage frm thermal bridges can be the same as the energy saved frm the use f a slar thermal system fr dmestic ht water. The rle f thermgraphy fr the identificatin f thermal cnductivities f materials during building inspectin was analysed. Pints made during discussin were as fllws: Fr assessing thermal cnductivities, infrared thermgraphy is a qualitative prcess nly. It is viewed as an expensive prcess fr field measurements. It has sme use fr training purpses. Other methds f n-site measurements, such as glazing system identificatin and ther methds which supprt energy perfrmance identificatin, may be useful, but need further discussin. Three different methds fr climatic nrmalisatin f energy uses with fcus n cling energy have been discussed: The heating and cling degree day methd (DDM) The mdified utilisatin factr methd (MUFM) The Climate Severity Index (CSI) Mst cuntries nly nrmalise accrding t heating degree days and d nt take int accunt the cling issue in terms f nrmalisatin. Weather nrmalisatin is a crucial task fr measured data and fr cmparing calculated data. The errr made by simply crrecting the heating and cling energy needs by degree days increases in high perfrmance buildings. Within the IEE prject ASIEPI, the climate severity index methd was used fr analysing the issue f the different lcal climates n the cmparisn f EP requirement levels amng different cuntries. The prject recmmended further develping f a climate severity index within CEN/ISO, as the need fr Eurpean/glbal cmparisns f energy uses and requirements will expand. A crrect and Eurpean-wide harmnised apprach fr the climate nrmalisatin fr bth heating and cling wuld simplify the intercmparisn f natinal requirements, as well as the use f measured energy rating. 4 Main utcmes frm the Prcedures sessins Tpic Main discussins and utcmes Cnclusin f tpic Future directins High perfrmance buildings Varius terms and definitins exist. Individual definitins are descriptive nly r are used differently in the cuntries. Often, the existing definitins d nt cmply with the natinal energy perfrmance calculatin methds. The market penetratin f high perfrmance buildings in Suthern Eurpean cuntries is significantly lwer than that in Middle and Nrthern Eurpean cuntries. Mst cuntries have natinal radmaps that include high perfrmance buildings as a gal fr future buildings. There is a need fr harmnised terms and definitins, taking int accunt natinal calculatin methds, neither limiting the technlgical ptins nr hindering innvatin. 19

20 Tpic Main discussins and utcmes Cnclusin f tpic Future directins Cmparisn f natinal requirements Setting minimum energy perfrmance requirements The cmparisns are influenced by varius parameters. The studies shuld include the ptential impact f these influence parameters. There is currently n rbust, simple and fair cmparisn methd available. The situatin might get even mre cmplicated if cst assessment is added t the cmparisn. Cst-benefit assessments fr setting requirements can be perfrmed frm different perspectives. Mst Member States already fix their requirements based n either financial r ecnmic cst-effectiveness calculatins. Many Member States fllw a prcedure similar t the planned methdlgy fr the cstptimum assessment f the EPBD recast. In additin t minimum energy perfrmance requirements n a building level and pssibly n the building envelpe, mst Member States have set requirements fr technical building systems, which vary in detail (at whle system r cmpnent level) and rate f use in the varius cuntries. Intercmparisn studies cannt be simply reduced t U-value cmparisns r t cmparisns f the energy cnsumptin in different cuntries. Member States wuld welcme a simple yet rbust framewrk fr the cst-ptimum methdlgy, which shuld als be as cnsistent as pssible with the established prcedures. Intercmparisns are extremely cmplicated and will remain a tpic fr indepth discussin in the future. Member States have t develp the natinal cntent and use the cmparative methdlgy. The definitin f natinal cntent and natinal use f the framewrk methdlgy can benefit frm exchange between Member States. The interface between prduct perfrmance infrmatin and system perfrmance calculatin, including part lad efficiency, needs t be imprved. Natinal prcedures Measured energy perfrmance rating N cuntry uses a ne-t-ne transfer f the CEN standards. The CEN standards ffer alternative paths, but the cuntries prefer t fix ne path. Sme CEN standards d nt cver the whle challenge f the EPBD. Quality cntrl and accreditatin f sftware needs t be further addressed. The prblem cncerning hw t crrectly mdel the summer perfrmance is nt cmpletely slved: ne-zne mdels can be insufficient fr summer cmfrt and cling, but multi-zne mdels need increased effrts and require simplificatins. In a significant number f cuntries, changes in the energy perfrmance prcedures have been already realised after the implementatin f the EPBD. The measured energy rating is perceived as a way t save effrts and mney. Cuntries are ften nt aware f the risks arising frm it. The existing systems fr benchmarking f the measured energy rating either need mre benchmark data and/r subcategries r fewer subcategries, in rder t facilitate the rating. Many cuntries use CEN cmpatible appraches. Multiple paths and requirements fr annexes cmplicate the direct use by the cuntries. The changes in energy perfrmance prcedures realised after the EPBD implementatin shw a general directin twards the tightening f the requirements and the cnfrmity with the CEN standards. There is n cmmn methd neither fr the nrmalisatin f measured energy nr fr the check f the data quality. Ways fr dividing the measured energy int different uses are als missing. Sme CEN standards shuld be extended t cver the whle field f applicatin. Barriers fr the use f the CEN standards have t be cmmunicated t CEN. There is a necessity fr further discussin n hw t cntrl the quality f sftware prgrammes and userinduced errrs. Infrmatin exchange n hw t prduce reliable benchmarks. Is a cmbinatin f calculated and measured energy rating useful and, if yes, fr which situatins? 20

21 Tpic Main discussins and utcmes Cnclusin f tpic Future directins Feasibility analysis f alternative systems The feasibility study requirement is transpsed differently int the Member States. The key factr is the timing f the feasibility study, which has t be carried ut when the strategic decisins are being made. Quality cntrl prcedures are unclear. Further experience is needed. Prcedures fr specific certificatin challenges The recmmendatins fr energy imprvements f existing buildings are derived in different ways in the Member States. A special challenge seems t be the quantificatin f recmmendatins when using measured energy rating. Cmplex and/r mixed use buildings are difficult t be certified, due t data availability, zning, identificatin f building systems, assignment f metres and quality f reference values. Practical ideas n hw t develp suitable recmmendatins are existing in the Member States. Reduced zne mdels, guides fr the installatin f metres and fr in situ measurements, as well as rules fr benchmarks are needed. Tpics including summer mdelling, prcedures and benchmarks fr measured energy rating, as well as ways t frm recmmendatins need t be addressed in depth. Thermal bridges The cuntries cver thermal bridges in different ways in their natinal EPBD implementatin regarding energy impact, limits, gd practice guidance and cmpliance checks at the design and realisatin phase f a building. Thermal bridges becme even mre imprtant in the case f high perfrmance buildings. A fllw-up f the impact f thermal bridges n the cling lad is needed. Infrared thermgraphy Thermgraphy can supprt the building inspectin by the identificatin f thermal cnductivities f materials. Results are mstly qualitative nly and require a lt f experience. The applicatin pssibilities are limited. Thermgraphy needs n further cnsideratin. Climate crrectin methds Weather nrmalisatin is a crucial task fr measured data and fr cmparing calculated data. In high perfrmance buildings, the errr made by simply crrecting heating and cling needs by degree days increases. A Eurpean-wide harmnised apprach fr the climate nrmalisatin within CEN/ ISO is recmmended. 5 Lessns learned and recmmendatins CA participants unanimusly welcmed the supprt and hints received frm ther Member States, as they all have cmparable issues t slve. Everybdy prfited frm the experience gained in the ther Member States. As it turned ut, high perfrmance buildings are named and/r defined differently in the Member States. Mst f the available definitins d nt take the natinal calculatin prcedures int accunt. Cmmn understanding n the use f terminlgy and the definitin f nearly zer-energy buildings are needed, accmpanied by a cmparisn with natinal ratings. The market penetratin f high perfrmance buildings in Suthern Eurpean cuntries is significantly lwer than in the rest f Eurpe. In rder t meet the EPBD recast target f nearly zer energy buildings by 2020, mst Suthern Eurpean Member States will have t bridge a larger gap. Experiences gained frm the intercmparisns f natinal requirement levels shwed that this is a very sensitive tpic and will becme even mre cmplicated if cst aspects are added. Cst-benefit assessments f the minimum energy perfrmance requirements are being perfrmed in mst EU Member States, frm either the financial r the ecnmic perspective. Many Member States use bth 21

22 assessment methds. The future EPBD recast framewrk methdlgy n this issue shuld try t accmmdate, bth, cuntries applying such assessments fr the first time and the assessment methdlgies in place in ther cuntries. In a significant number f cuntries, changes in the EP prcedures have been already realised after the implementatin f the EPBD. Nearly all the cuntries in which changes have been realised, have tightened their EP requirements. Weather nrmalisatin is a crucial task when using measured data, but is als imprtant when ding calculatins. Cling energy is nly partly influenced by simple temperature differences that can be crrected by degree days r similar. The mistake made by simply crrecting the heating energy need (instead f the thermal and ventilatin lsses) by degree days, becmes bigger in the case f high perfrmance buildings. A Eurpean-wide harmnised apprach fr the climate nrmalisatin within CEN/ISO is recmmended. Assignment f meters, divisin int different uses, suitable benchmarks, nrmalisatin and derivatin f recmmendatins, are sme f the prblems f measured energy rating. Guidelines and minimum requirements fr a crrect prcedure fr measured energy rating are missing. Calculated energy rating discussins are abut the necessary cmplexity in zning and the accreditatin f sftware. Simplificatins fr the handling f sme calculatin methds have t be fund, whereas ther methds need t be made mre detailed, in rder t give reliable results with acceptable accuracy in specific situatins. Due t practicability reasns and desired independency, the CEN standards are nt transferred ne-t-ne int the natinal prcedures. Instead, the cntent is incrprated int the natinal dcuments. Thus, the CEN standards shuld be further develped int general framewrk dcuments that fix general principles nly and allw maximum flexibility fr the implementatin in each cuntry. The infrmatin exchange with Eurpean prjects that can ffer slutins fr the challenges existing in the natinal prcedures prved t be a useful supplement t the Cncerted Actin wrk. This reprt is funded by the Cmmunity s Intelligent Energy Eurpe prgramme under the cntract IEE/CA/07/333 The sle respnsibility fr the cntent f this publicatin lies with the authrs. It des nt necessarily reflect the fficial pinin f the EACI, the Eurpean Cmmissin r ther Eurpean Institutins. Neither the EACI, nr the Eurpean Cmmissin nr any ther Eurpean Institutins are respnsible fr any use that may be made f the infrmatin cntained herein. The cntent is given fr infrmatin purpses nly and des nt legally bind any f the parties invlved. Eurpean Unin, 2011 Mre details n the IEE Prgramme can be fund at This reprt can be dwnladed frm and als frm 22