A PROPOSAL OF GUIDELINES FOR ENERGY CERTIFICATION OF THE MEDITERRANEAN BUILDING TYPOLOGIES: THE LIFE PROJECT SUN&WIND

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1 A PROPOSAL OF GUIDELINES FOR ENERGY CERTIFICATION OF THE MEDITERRANEAN BUILDING TYPOLOGIES: THE LIFE PROJECT SUN&WIND Maurzo CELLURA Prof.Eng. 1 Ornella AMARA Arch. 2 Marco BECCALI Prof.Eng. 3 Maro FONTANA Eng. 4 Marna MISTRETTA Eng. 5 Dpartmento d Rcerche Energetche e Ambental, Unverstà degl Stud d Palermo, Palermo, Italy 1 mcellura@dream.unpa.t, 3 marco.beccal@dream.unpa.t, 4 fontana@dream.unpa.t 2 Comune d Palermo, Palermo, Italy parcherserve@comune.palermo.t 5 Unverstà degl Stud Medterranea d Reggo Calabra, Reggo Calabra,Italy mstretta@dream.unpa.t Keywords: buldng, certfcaton, energy effcency, gudelnes, LCA, materals, Medterranean Summary Ths paper descrbes part of the work carred out n the framework of the UE Lfe Sun & Wnd Project (ENV/IT/ ). The man am of the project s to propose plannng strateges and poltcal actons to be shared by the local authortes n order to promote the use of local buldng materals and constructon technques of the Medterranean area.. Techncal and methodologcal tools have been defned to address desgn and constructon processes to energy savng, energy effcency and envronmental desgn. Moreover, new gudelnes for energy and envronmental certfcaton of buldngs are proposed. These gudelnes, obvously complant wth the EU drectve 2002/91/CE and the Italan energy-savng laws, ntroduce a sutable set of envronmental crtera. These crtera wll allow to assess the sustanablty of the buldng n a more comprehensve way, dealng wth resources consumpton, envronmental loads and ndoor comfort, use of local materals, energy self-generaton from renewable sources, CO 2 emsson from HVAC, solar radaton control, thermal nerta of the buldng envelope, daylghtng, and acoustc nsulaton. The most nnovatve content s the one related to a subset of crtera assessng the energy content of materals by means of a smplfed LCA approach, as emboded energy and use of ecologcal materals. A specfc local database wll be created soon. Ranges of values and ther respectve ranks are outlned to establsh the overall qualty buldngs. 1. Introducton The worldwde defnton of sustanablty encompasses a varety of topcs rangng from economc and socal development, to the management of human settlements and buldng practces. In partcular, the Agenda XXI programme was addressed to envronmental ssues, such as the use of local buldng materals, the promoton of tradtonal technques wth regonal resources, the regulaton of energy effcent desgn rules, the recyclng and reuse of buldng materals, especally those requrng ntensve energy use durng manufacturng. From ths vewpont a sustanable buldng s charactersed by the mnmsaton of the envronmental mpacts due to the resources and energy consumpton and the CO 2 emssons durng ts lfespan (Klunder, 2004). Developed countres need a hgh rate of energy consumpton to mantan ther standard of lvng and comfort. The current challenge s to seek sustanable development, mantanng transformaton and progress levels whle adaptng needs to the exstng resources and therefore achevng energy savng (Rey et al., 2007). The promoton of energy effcency s a key ssue of polces and measures needed to match the Kyoto protocol target. The buldng sector, because of ts hgh energy demand, has a relevant share n the EU energy balance and n the CO 2 emssons scenaro. In partcular, t accounts for more than 40% of the fnal energy consumpton n the EU and s rsng. Such trend s destned to ncrease the energy consumpton and hence ts carbon doxde emssons wthout the adopton of sutable envronmental polces. In such a context energy savng s an mportant ssue for the urban sustanablty (Ardente et al., 2007). Certfcaton schemes have to be mplemented to promote hgher energy performance standards, provdng a detaled nformaton about the buldng s energy performance (Casals, 2006). The ndcators mplemented n the energy certfcaton wll nfluence ts effcacy to control and lmt the energy consumpton. 33

2 In ths paper authors present a tool for energy and envronmental certfcaton of buldngs developed wthn the UE Lfe Sun & Wnd Project (ENV/IT/ ). The am of such project s the valorzaton of buldng materals and constructon technques of the Medterranean area, by means of the ntroducton of plannng strateges and actons to be shared by the local authortes. In partcular, techncal and methodologcal tools have been defned to address desgn and constructon processes to energy savng, energy effcency and envronmental desgn. The energy balance assessment of the buldng s assessed In complance wth Italan natonal rules as follow-up of the EU drectve 2002/91/CE. A sutable set of envronmental crtera s ntroduced to assess the sustanablty of the buldng, such as use of local materals, self-generaton of electrcty from renewable sources, CO 2 emsson from HVAC, solar radaton control, thermal nerta of the buldng envelope, daylghtng, and acoustc nsulaton. The basc scheme s the one of the GBTool (Ardente et al., 2004), and of the Italan Protocollo ITACA. New sutable crtera have been ntroduced n order to assess the energy content of materals by means of a smplfed Lfe Cycle Analyss (LCA) approach, as emboded energy and use of ecologcal materals. Ranges of values and ther respectve ranks are outlned to establsh the overall qualty buldngs. 2. Energy Certfcaton The current EU energy approach on buldng sector s represented by Drectve 2002/91/CE on the energy performance of buldngs (European Parlament, 2002) whose prmary am s to ncrease energy performance levels of buldngs by means of the mplementaton of energy certfcaton programs. It ponts out that energy savng can be acheved sgnfcantly through the applcaton of energy-effcency methods and technologes, based on: - mprovement of the buldng envelope, wth the focus on thermal nsulaton and glazng; - mprovement of the nstalled equpment, e.g. lghtng and ar condtonng; - ntroducton of envronmentally-frendly energy-generaton nstallatons; - ntroducton of boclmatc buldng desgn and orentaton. Energy certfcaton of a buldng s the statement of ts energy performance, through a document called energy certfcate whch must nclude reference values based on current gudelnes and comparatve assessments, and suggestons of mprovement (Aboul Naga et al., 2001). To acheve ths objectve, energy certfcaton must provde clear and detaled nformaton about the buldng energy performance, allowng for drect comparson among dfferent buldngs. The ndcators mplemented n the energy certfcaton wll nfluence ts effcacy to control and lmt the energy consumpton. Any calculaton methodology for energy certfcaton should nclude aspects such as thermal characterstcs, buldng shell, thermal equpment, lghtng, orentaton, renewable energy sources, ventlaton and ndoor clmate condtons (Casals, 2006). A proper energy certfcaton scheme gves added value to the buldng and allows allocaton of economc ncentves to drve the buldng sector towards sustanablty. 3. UE Lfe Sun & Wnd Project (ENV/IT/ ): outlnes and objectves As focused by the Italan buldng energy law (D. lgs 2007/311) n complance wth Drectve 2002/91/CE local authortes play a relevant role n the achevement of effectve actons amed to energy performance mprovement, adoptng controllng procedures for planners and bulders to verfy whether the buldng desgn s matches wth the expected target of energy performance. In such a context the UE Lfe Sun and Wnd Project s a local sustanable development acton addressed to ntegrate envronmental ssues nto buldng plannng, wth emphass on Medterranean hertage of buldng materals and technques. The goal s to encourage a buldng model where materals and constructon technques allows low energy consumpton and envronmental mpacts durng ts lfe cycle. In partcular, techncal and methodologcal tools are defned to address desgn and constructon processes to energy savng, energy effcency and envronmental comfort. For such purpose, many actons have been developed, such as: - the development of a database whch ncludes exstng buldng typologes n the Medterranean context; - the drawng up of Gudelnes for the Sun & Wnd Certfcaton to provde suggestons about the sutable technologes and desgn rules, for mprovng energy and envronmental performances of urban settlements, both for new buldngs and for the exstng ones; - a comparatve survey of the natonal and regonal laws and regulatons n force n the Partner Countres (Greece, Italy, Span); - the desgn, constructon and montorng of two prototypes to be bult accordng to the rules fxed n the above gudelnes; - a proposal for some economc ncentves or de-taxaton for new constructons and/or the rehabltaton of exstng buldngs; 34

3 - the defnton of proposals for Product Specfc Requrements (PSR) of typcal Medterranean buldng materals to obtan the Envronmental Product Declaraton (EPD) ; - the dssemnaton of the obtaned results through forums, conferences, and publcaton of outcomes. In complance wth the CIPE Resoluton 2002/57 (CIPE, 2002) on the Natonal Strateges for the Sustanable Development, each Italan Regon must fx ts own strateges for the sustanable development. Therefore, the fnal am of the Lfe Sun and Wnd project s to acheve the ntroducton of the gudelnes for the Sun & Wnd Certfcaton nto the Regonal Strateges on Sustanable Development document, that Envronmental Authorty of Sclan Regon wll present at the State-Regon Conference and wll formally adopt wthn the tme project (2008). Hence, the complance wth the above gudelnes wll represent the requred condton. 3.1 Proposal of gudelnes for the energy and envronmental certfcaton Sun & Wnd of the Medterranean buldng types Boclmatc archtecture lterature consder the followng factors to be taken nto account n the constructon of an energy-effcent buldng (Bart P. et al., 2007): - topography, e.g. slope and ste orentaton; - sun path durng the year (solar alttude and azmuth); - clmatc condtons, ncludng prevalng wnd patterns, ncomng solar radaton, temperature, ar mosture; - envronmental condtons such as daylght and shadng of the constructon ste; - mass, volume and sze of buldng; - local archtectural standards; - avalablty of local buldng materals. Such envronmental and techncal factors have been taken nto account n the present study, whch s carred out wthn the task 4 of the UE Lfe Sun & Wnd Project (ENV/IT/ ). Gudelnes for the Sun & Wnd certfcaton have been drafted to provde a voluntary tool of envronmental and energy certfcaton, focusng on features and requrements of the Medterranean boclmatc archtecture. In partcular, the followng envronmentally-frendly strateges on materal and energy flows are taken nto account: - boclmatc buldng desgn and orentaton (low-energy archtecture and applcaton of daylghtng); - ntegraton of solar-actve thermal and photovoltac systems nto buldng structures; - heat recovery, ncludng sewage system, ventlaton and ar condtonng systems; - waste sortng, collectng and re-use of wastes; - water management, ncludng ntroducton of water-savng equpment, water treatment, re-use of ran water. The buldng sze s a sgnfcant startng pont, snce t nfluences the approach and the crtera n the Sun & Wnd Certfcaton scheme. In such a context the buldng sze s splt n two clusters: 1. Buldng wth a net floor surface less than 1000 m 2 ; 2. Buldng wth a net floor surface hgher than 1000 m 2. For the frst group of buldngs energy prmary consumpton represents the man factor of envronmental mpact. Therefore, the certfcaton scheme wll comply the Italan energy law (D. lgs 2007/311), but factors of assessment, such as clmatc parameters, geometrc features of buldngs, and thermal propertes of buldng materals and components, wll be strctly referred to the Medterranean context and retrofttng operatons. For the second group of buldngs a more comprehensve method s proposed to assess energy and envronmental performance of the buldng, accordng to a sutable set of ndcators. The rank of the buldng performance wll be based on fxed reference values for each ndcator. In the latter case the startng pont s the smplfed ITACA Protocol (ITACA, 2004), derved from the GB Challeng tool (GBC, 2002). Sutable crtera whch have a sgnfcant weght for the Medterranean buldng types are also ntroduced, such as use of local materals, self-generaton of energy power from solar energy, solar radaton control, CO 2 emsson from HVAC, and thermal nerta of the buldng envelope Set of envronmental crtera The envronmental crtera selected to assess the sustanablty of the buldng deal wth the followng ssues: consumpton of resources (energy, water and materals); envronmental loadng (greenhouse gases emsson, ozone depleton substances, constructon and demolton wastes, water effluents); ndoor envronmental qualty (thermal comfort, lghtng, acoustc nsulatng, ventlaton); qualty of servce, whch ncludes: adaptablty of the buldng, controllablty, mantenance. Table 1 shows the selected energy crtera for assessng energy performances: - thermal nsulaton, estmated by means of the thermal transmttance [W/(m 2 K)] of each component of the buldng envelope, accordng to the UNI EN ISO standards (UNI 10351, UNI 10355, UNI EN ISO 6946). The thresholds values fxed by the Italan law (D.lgs 311/2007) are assumed as reference values; - control of solar radaton, estmated through the average shadng factor; 35

4 - hot water producton by solar collectors [%], assessed as percentage of the annual thermal energy consumpton; - self-producton of energy power from renewable sources (PV collectors); - effcent electrc equpments (household applances and lghtng energy consumpton) - emboded energy of constructon materals [MJ/m 2 ]; - use of ecologcal products. Table 1 Set of envronmental crtera selected for the assessment procedure Envronmental Issue Crtera Sub-crtera Outdoor Envronmental Qualty Resources Consumpton Outdoor Envronmental Comfort Integraton wth the envronment Energy consumpton Albedo of the outdoor spaces Integraton wth natural envronment Integraton wth bult envronment Thermal nsulaton Solar Radaton control Producton of Hot Water Own-generaton of electrc power from renewable sources Effcency of electrc equpments Emboded energy of buldng materals Use of ecologcal products Potable water net consumpton Potable water net consumpton Recyclng of exstng buldng Recycle of exstng structures Envronmental loads Indoor Envronmental Qualty Servce qualty Management qualty Use of local materals CO 2 emsson reducton Ran water year Sold Waste from constructon or demolton Vsual Comfort Thermal Comfort Acoustc polluton Buldng and system mantenance Avalablty of buldng techncal documentaton Use of local materals Greenhouse gases emsson Ran amount n a year Sold Waste from constructon or demolton Day lghtng Thermal nerta Facade acoustc nsulaton Acoustc nsulaton from tramplng and atmospherc agents Montorng of the consumptons Avalablty of buldng techncal documentaton (Mantenance Handbook) For each crteron the followng features are descrbed: - goal to be acheved; - quanttatve/qualtatve parameter to assess the performance of the buldng; - procedure utlsed to assess the ndcator; - performance scale for the rankng of the buldng; - suggested strateges to adopt for mprovng the buldng performance; - references, rules and current laws. 36

5 3.1.2 LCA and energy certfcaton Accordng to the LCA approach of the ISO seres, energy balance of a buldng should nclude each lfe cycle step. Hence the followng amounts should be assessed: emboded energy of the buldng materals and servce plants; energy consumpton n the constructon phase; operatng energy consumpton for the dfferent buldngs equpments, as heatng, coolng, ventlaton, lghtng, and household applances; energy consumpton for mantenance and refurbshment, ncludng also recurrng emboded energy consumed to mantan, repar, restore, refurbsh or replace materals, components or systems; energy consumpton n the buldng dsmantlng and n the dsposal or recyclng/reuse of debrs; energy consumpton for transport n each steps. Fgure 1 shows the scheme of energy and envronmental certfcaton of the proposed buldngs Emboded energy Emboded energy s the energy consumed by all of the processes assocated wth the producton of a buldng, from the acquston of natural resources to the product delvery. Ths ncludes the mnng and manufacturng of materals and equpment, the transportaton of the materals and the admnstratve functons. Emboded energy s a sgnfcant component of the lfecycle mpact of a home (Mlne G. et al., 2005). It allows straghtforward comparsons between alternatve buldng materals and components and can ad to determne desgn decsons on materal selecton (Yohans et al., 2002). The assessment of the emboded energy s rather complex, snce nvolves a number of sources of data. It requres the calculaton of the specfc ndcator of mpact, measured as the quantty of emboded energy n the buldng per unt of area [MJ/m 2 ]. For such reason, authors suggest a frst smplfed approach to assess the emboded energy of the buldng materals used n the constructon step. A more detaled energy assessment should nclude all the steps of the buldng lfe cycle (transportaton of materals from manufacturng ste to the constructon ste, buldng constructon, operaton and mantenance, and dsmantlng). Emboded energy of varous materals, components and systems depends not only from constructon methods and the type of the buldng, but also from ste locaton, materals used and the orgn of these materals. Ths s why eco-profles of buldng materal often dffer from one country to another. For the tme beng, there are not general and relable data for specfc emboded energy of the dfferent materals, but the authors are workng to create a specfc local database for the Sclan context Use of ecologcal materals crteron Ths crteron has been ntroduced n order to enhance the utlzaton of low mpact materals (Ardente et al., 2005). It s assessed as rato of emboded energy n the ecologcal buldng materals to the overall emboded energy. Ecologcal materals are defned those ones whch have obtaned envronmental certfcaton accordng ISO or are produced by manufacturers havng a certfed envronmental management system (ISO 14001, EMAS, Ecolabel). In detal the performance ndcator I s calculated wth the followng expresson: I = j M c, j M E c, j E p j (1) where: M c,j s the mass of the j th ecologcal materal [kg]; E c,j s the emboded energy of the j th ecologcal materal [MJ/kg]; p j s the weght assgned to the certfcaton typology of the j th ecologcal materal n the followng way: - p j = 3 for a product wth Type I Envronmental Labellng (.e. Ecolabel); - p j = 2 for a product wth Type III Envronmental Labellng (.e. EPD); - p j = 1.5 for a product of a frm wth EMAS regstraton; - p j = 1 for a product of a frm wth ISO certfcaton; - p j = 0.5 for a product wth Type II Envronmental Labellng (.e. self-declaraton); M s the mass of the th materal [kg]; E c,i s the emboded energy of the th materal [MJ/kg]; 37

6 M E represents the overall emboded energy assessed n the prevous paragraph. Structural Data - Detaled masses of the utlzed buldng materals Constructon Step - Constructon - Transport of materals to the constructon ste Envronmental Database - Eco-profle of the materals employed for structures and operatng systems Emboded energy Assessment of : - Emboded energy - Feedstock energy - Impacts due to the buldng constructon Buldng-plant System - Dmenson - Adjacent buldngs - Ste locaton - Plant performances (resources uses, effcency, etc.) Operatng Step - Buldng use and mantenance Operatng Step - Energy mpact assessment Certfcazone Energy Energetca Certfcaton Data on buldng demolton -Dsmantlng -Dsposal- and materals recyclng End Lfe -Energy and envronmental mpact assessment n the buldng demolton step Buldng Lfe Cycle Analyss Assessment - of energy-envronmental ndcators and ndces (Rule : ISO 14040) Ecodesgn - Use of ecologcal materals (.e. - certfed envronmental products) - Frm wth EMAS regstraton or ISO certfcaton Renewable energy sources and materals recyclng/re-use Selecton of crtera to optmze envronmental performance ( Rule: CE761/01, ISO 14001, Ecolabel reulaton and EPD Regulaton) Envronmental Certfcaton Fgure 1. A scheme of energy and envronmental certfcaton. 38

7 Buldng Lfe Emboded Energy Constructon Use Refurbshment Use Demolton Mnng of materals Manufacture of components Transport to ste Constructon Process Replacement materals components of and Mnng of materals Manufacture of components Transport to buldngs Replacement of materals and components Demolton Transport Operatng Energy Heatng and/or coolng Lghtng Applances Power tools Energy loads for on-gong uses Heatng and coolng Lghtng Applances Recyclng of materals/components Fgure 2 Emboded and operatonal energy components n the buldng lfe cycle, from (Poel et al., 2007) CO 2 emsson crteron CO 2 emsson crteron assesses the carbon doxde (CO 2 ) emsson due to the energy consumpton for buldng clmatsaton. The followng assessment method have been proposed: 1. annual CO 2 emsson per m 2 of useful area on the bass of the annual prmary energy demand and of the emsson factor of the used fossl fuels (.e. ol, natural gas); 2. annual CO 2 emsson referred to the standard annual energy demand per m 2 of useful area, usng natural gas as fuel ; 3. to assess the performance ndcator I CO2 as followng: EF, CO E 2 p, I CO = (2) 2 EFCH SE 4 CH 4 where: - EF CO2 s the CO 2 emsson factor of the th fossl fuel [kgco 2 /GJ]; - E p, s the annual prmary energy demand per m 2 of useful area [GJ/m 2 ]; - EF CH4 s the CO 2 emsson factor of natural gas [kgco 2 /GJ]; - SE CH4 s the standard annual energy demand per m 2 of useful area, dependng on the clmatc zone [GJ/m 2 ] (D lgs 311/2007). Concluson Gven the hgh relatve weght of the buldng sector n the energy balance of the developed countres, the very lmted penetraton of energy and envronmental assessment tools n such sector and the dffcultes to ntroduce relevant changes, strateges of energy and envronmental conscous desgn have to become key ssues to mplement sustanable and successful polcy. All the stakeholders are called to promote them n a cost effectve and envronmentally conscous way. Hence, t s necessary to ntroduce tools and measures that reduce the mpact of such sector and to develop gudelnes and standards that rule the energy assessment n the buldng sector, extended to desgn, constructon, management and dsposal. However, t s relevant to establsh clear objectves for the dfferent actons to undertake; the envronmental assessment methods upon whch the sustanable certfcaton s based, as well ther transparency, are key elements for ts success as shown by some European experence. Emboded energy data and Lfe Cycle Analyss should be ncluded n energy certfcaton schemes n order to effectvely lead the buldng sector toward sustanablty. The Lfe Cycle thnkng seems to be the most relable approach snce t encompasses 39

8 all the lfe phase of the buldng. Therefore t s surprsng that even nowadays LCA s not consdered n the most advanced buldng energy laws (Ardente et al., 2007). In such a context the UE Lfe Sun & Wnd Project (ENV/IT/ ) represents an acton voted to promote materals and constructon technques nvolvng low energy consumpton and low envronmental mpacts durng the lfe cycle of a buldng. The focus on the local buldng hertage s partcularly stressed. In fact, the am of such project s the valorzaton of buldng materals and constructon technques of the Medterranean area, by means of the ntroducton of plannng strateges and actons to be shared by the local authortes. The authors have presented a methodology for assessng the buldng sustanablty, by means of a sutable set of crtera and sub-crtera. In ths way desgn and constructon processes should be addressed to energy savng, energy effcency and envronmental comfort. Such scheme has been ntroduced n the mplementaton of the gudelnes for the Sun & Wnd certfcaton, whch have been drafted to provde a voluntary tool of envronmental and energy certfcaton, focusng on features and requrements of the Medterranean boclmatc archtecture. Such gudelnes have to establsh thresholds values n buldng energy consumpton and to rank buldng energy performance. They represent an effort for enhancng energy and envronmental performance of buldngs, whle mantanng hgh level of ndoor envronmental comfort. References Aboul Naga M. M. and Elsheshtawy Y.E 2001, Envronmental sustanablty assessment of buldngs n hot clmates: the case of the UAE, Renewable Energy 24, pp Ardente F., Beccal G., Cellura M., Mstretta M. and Spnnato MT 2004, Applcaton of sustanablty buldng ndces n the Medterranean constructons, Proceedngs of the 1 st European Networks Conference on Sustanablty n Practce Berln, Aprl 1 st. Ardente F., Beccal M., Cellura M. and Mstretta M. 2007, Buldng energy performance: A LCA case study of kenaf-fbres nsulaton board, Energy and Buldng, avalable onlne at Ardente F., Beccal G., Cellura M., Marchese S. and Mstretta M. 2005, Dcharazone Ambentale d Prodotto Applcata a Materal Boedl, La Termotecnca, LIX, December, pp (In Italan language). Beccal M., Cellura M. and Mstretta M. 2007, Envronmental effects of energy polcy n Scly: the role of renewable energy, Renewable and Sustanable Energy Revews 11(2), pp Comtato Intermnsterale per la Programmazone Economca (CIPE) 2002, Italan Delberaton Nu.57 on the Natonal Strateges for the Sustanable Development, Offcal Gazzette nu. 255 (In Italan language). Decreto Legslatvo 2007/311 Dsposzon correttve ed ntegratve al decreto legslatvo 19 agosto 2005 n. 192, recante attuazone della drettva 2002/91/CE, relatva al rendmento energetco nell'edlza, publshed on Offcal Gazette 2007 February 1st (In Italan language). European Parlament 2002, Drectve 2002/91/CE of 16 December 2002 on the energy performance of buldngs. Garcìa-Casals X. 2006, Analyss of buldng energy regulaton and certfcaton n Europe: Ther role, lmtatons and dfferences, Energy and Buldngs 38, pp GBC 2002, Green Buldng Challenge 2002, GBtool User Manual, SBE Internatonal Intatve for a Sustanable Bult Envronment. ITACA 2004, Protocollo ITACA semplfcato per la valutazone della qualtà energetca ed ambentale d un edfco, Gruppo d Lavoro Interregonale n matera d boedlza, Roma, 15 gennao. Klunder G. 2004, The search for the most eco-effcent strateges for sustanable housng constructon; Dutch lessons, Journal of Housng and the Bult Envronment 19, pp Mlne G. and Reardon C.2005, Techncal Manual. Desgn for lfestyle and the future n Australa's gude to envronmentally sustanable homes, at Poel B., van Cruchten G. and Balaras C.A. 2007, Energy performance assessment of exstng dwellngs, Energy and Buldngs 39, pp Rey F.J. and E. Velasco, F. Varela 2007, Buldng Energy Analyss (BEA): A methodology to assess buldng energy labelng, Energy and Buldngs 39, pp UNI 10351, 1994, Materal da costruzone. Conduttvtà termca e permeabltà al vapore (In Italan language). UNI 10355, 1994, Murature e sola. Valor della resstenza termca e metodo d calcolo (In Italan language). UNI EN ISO 6946, 1999, Component e element per edlza - Resstenza termca e trasmttanza termca - Metodo d calcolo, (In Italan language). Yohans Y.G. and Norton B. 2002, Lfe-cycle operatonal and emboded energy for a generc sngle-storey offce buldng n the UK, Energy 27, pp