the life cycle performance of sustainable renovation concepts

THE LIFE CYCLE PERFORMANCEOF SUSTAINABLE RENOVATIONCONCEPTSA PERFORMANCE EVALUATION OF WARMBOUWENJ.P. VINKUNIVERSITY OF TWENTE10/20/2010

THE LIFE CYCLE PERFORMANCEOF SUSTAINABLE RENOVATIONCONCEPTSA PERFORMANCE EVALUATION OF WARMBOUWENCONTENT:TITLE:SUBTITLE:MASTER THESISTHE LIFE CYCLE PERFORMANCE OF SUSTAINABLE RENOVATION CONCEPTSA PERFORMANCE EVALUATION OF WARMBOUWENNAME:J.P. VINKSTUDENT NUMBER: 0048267UNIVERSITY:MASTER TRACK:INTERNSHIP:UNIVERSITY OF TWENTECONSTRUCTION MANAGEMENT & ENGINEERINGLOCAL COMPANY, AMSTERDAMSUPERVISORS: PROF.DR.IR. J.I.M. HALMAN UNIVERSITY OF TWENTEDR.IR. E. DURMISEVIC UNIVERSITY OF TWENTEDRS. P. BOSWINKEL MRE MRICS LOCAL COMPANYDATE: 10/20/20103

PREFACEThis report is the result of a scientific research that is executed to finish the master trackConstruction Management & Engineering at the University of Twente, the Netherlands.The research is executed at Local Company in Amsterdam.The focus of this research is on sustainability in the built environment. This subject hasgained a lot of attention during the past few years. Professionals, companies,governments and other instances increasingly become aware of the importance ofsustainability and the importance of creating a balance between human live and our mainresource, planet earth. Currently, our society is facing the sustainable challenge, butlarge scale improvements are still ahead of us. Despite the increasing attention forsustainability; energy use, environmental degradation and depletion of resources isincreasing in time.When I started this research, I thought to have sufficient knowledge of the researchsubject to execute this research within the prescribed duration of the master thesisprocess. However, during the execution of this research the complexity and holisticcharacter of the sustainable challenge became clear to me, which made me aware of thefact that the selection of a real interesting subject was less easy than initially thought.The awareness of the complexity and holistic character of the sustainable challengemakes me optimistic and pessimistic at the same time; optimistic because I see manychances to improve the current situation and pessimistic because there are still so manythings to improve before real sustainability is realized. The insights I have gained duringthe execution of this research convinced me of the importance and urgency of thesustainability challenge. As a result, I have adopted the sustainability challenge and Ihope to contribute to this challenge during my professional career. Personally, I considerthis report as the start of my contribution to the realization of a sustainable builtenvironment.I would like to thank I. Opstelten, G. Abdalla, P. Oei, M. de Gier, M. Karthaus, R. van derVeeken, B. Hoogvliet, D. van der Wal, P. Tielkes, R. van Eeuwijk, J. Mak, M. Dansen, A.van Kessel, and P. Vandeginste for their cooperation and the valuable information theyprovided for this research. Also, I would like to thank S. Binnemars, T. van der Merwe,and M. Toxopeus for their useful help and support. I am very grateful to O. van Kampen,who provided me with very useful information about the principle of life cycle costing andgave me the opportunity to work with the software tool LCC-Lite. Also I am very gratefulto G. Verbaan, who helped me to define technical characteristics of WarmBouwen andgave me the opportunity to work with the software tool EPW.I want to express my special thanks to my supervisors; J.I.M. Halman for his usefulfeedback and support, E. Durmisevic for the time she has spend to help me, her criticalview and useful feedback, and the interesting conversations during our meetings, and P.Boswinkel for his feedback and support, his great enthusiasm, and for involving me atLocal Company and its day-to-day activities.Lastly, I want to thank my family and especially my girlfriend Marije, who supported meand was there for me when I needed her.I had a great time at Local Company during the execution of this research. I am proudand satisfied with the end result. I am glad to accomplish my educational career with thismaster thesis and I am looking forward to receive my Master‟s degree.Jetse VinkAmsterdam, October 20105

MANAGEMENT SUMMARYSustainability in the built environment is a subject with an increasing economic and socialrelevance. Important aspects of this subject are the continuous increasing use of energy,increasing energy costs, and increasing material use on earth. These aspects result inCO 2 emission and climate change, resource depletion, and financial issues. Theapplication of sustainable renovation is considered to be an effective strategy tocontribute to the transition process towards a more sustainable built environment.However, it is hard to determine which sustainable renovation concept is the mosteffective one for a renovation project. Selecting the most effective sustainable renovationconcept demands the possibility to compare the performances of different concepts witheach other. To determine the performance of a renovation concept, the factors ofinfluence on the performance must be identified.This research focuses on the identification of factors of influence on the performance of asustainable renovation concept. These factors of influence are integrated into a modelthat can be used to determine and compare the performance of a sustainable renovationconcept. The identification of factors of influence and the development of the model arebased on a literature study, an evaluation of existing sustainability assessment tools,expert interviews, and a model testing phase.This research also identifies factors of influence on the market implementation of aninnovative sustainable renovation concept. The identification of these factors of influenceis based on a literature study and expert interviews.The factors life cycle costs, life cycle yields, life cycle environmental impact, quality, andenergy performance coefficient are the five main factors of influence on the performanceof a sustainable renovation concept. Also, boundary conditions influence the performanceof a sustainable renovation concept at a specific project. The identified main factors ofinfluence and the boundary conditions are integrated into a „life cycle performanceevaluation model‟ for sustainable renovation concepts.The factors system change process, adoption of innovation, legislation & rules, process &organization, and technical feasibility are factors of influence on the marketimplementation of an innovative sustainable renovation concept. These identified factorsare integrated into an „implementation model‟ for innovative sustainable renovationconcepts.The developed „life cycle performance evaluation model‟ is applied on a case. This caseconsists of the performance evaluation of the selected renovation alternatives „norenovation‟, standard renovation‟, and „WarmBouwen renovation‟. „WarmBouwen‟ is aninnovative sustainable renovation concept. The model application points out that theWarmBouwen renovation concept scores the best on the factors life cycle yields, life cycleenvironmental impact, quality, and energy performance coefficient at all definedscenarios. WarmBouwen scores better than the alternative „standard renovation‟ at alldefined scenarios on the factor life cycle costs. WarmBouwen scores better than „norenovation‟ at 21 of the 27 defined scenarios.The performance of the WarmBouwen concept can be improved by applying a gas heatpump instead of an electric heat pump, by applying solar energy systems, and byreplacing the existing fixed interior walls of a house by flexible interior walls.6

INDEXPREFACE .............................................................................................................. 5MANAGEMENT SUMMARY ........................................................................................ 61. BACKGROUND .............................................................................................. 81.1 INTRODUCTION 81.2 LOCAL COMPANY & WARMBOUWEN 122. RESEARCH DESCRIPTION ..............................................................................132.1 PROBLEM DEFINITION 132.2 RESEARCH GOAL 132.3 RESEARCH QUESTIONS 142.4 RESEARCH MODEL 142.5 RESEARCH METHODOLOGY 152.6 RESEARCH SCOPE 193. THEORETICAL BACKGROUND .........................................................................203.1 IMPLEMENTING AN INNOVATIVE RENOVATION CONCEPT 203.2 SUSTAINABILITY 323.3 SUSTAINABLE RENOVATION 343.4 EXISTING SUSTAINABILITY ASSESSMENT TOOLS 363.5 LIFE CYCLE ASSESSMENT 383.6 LIFE CYCLE COSTING 423.7 CONCLUSION - CONCEPT MODEL 444. MODEL........................................................................................................454.1 MODEL DEVELOPMENT 464.2 MODEL & EXPLANATION 475. MODEL APPLICATION ....................................................................................585.1 CASE WARMBOUWEN 595.2 BOUNDARY CONDITIONS 645.3 MODEL OUTPUT - COMPOSITION AND CORRELATION 655.4 MODEL OUTPUT - PERFORMANCE OF WARMBOUWEN 735.5 IMPROVEMENTS FOR WARMBOUWEN 776. DISCUSSION ...............................................................................................796.1 MODEL 796.2 MODEL APPLICATION 806.3 RESULTS 807. CONCLUSIONS .............................................................................................837.1 CONCLUSIONS 837.2 FURTHER RESEARCH 88BIBLIOGRAPHY.....................................................................................................89APPENDICES ........................................................................................................937

1. BACKGROUNDThis chapter describes the background of the research.1.1 INTRODUCTIONSustainability and a sustainable built environment is an increasing economic and socialsubject. Important aspects of this subject are the continuous increasing use of energyand materials on earth. Material use results in depletion of resources and energy useresults in depletion of resources and CO 2 emission. CO 2 emission on its turn is consideredto be the main cause of climate change on earth (Olivier, van den Berg & Peters, 2000 &NEAA, 2008). In December 2008 the European Union agreed on a plan which containsimportant targets concerning sustainability. Important aspects of this plan are the targetsto reduce CO 2 emissions by 30% in 2020, compared with the CO 2 emission in the year1990, and to increase the share of renewable energy to 20% of the total energyproduction in the Netherlands. On the 19 th of December 2009, the UN ClimateConference in Copenhagen was ended. This conference was organized to set up globaljuridical committing measures against global heating and climate change, as successor ofthe Kyoto-protocol from 1997. Despite the intentions, the conference ended up in adisappointment. The U.S.A., China en other large upcoming economies have only madesome non-committing agreements against climate change. (www.europa-nu.nl)THE BUILT ENVIRONMENTAn analysis of the energy use in theNetherlands shows that the builtenvironment is a large contributor of thetotal energy use. Figure 1 visualizes therelation between energy use and climatechange. The built environment in theNetherlands causes about 35% percent ofthe total energy use in the Netherlands(Koene, 2007). Also, there is a bigpotential to decrease energy use inCO2 emissionClimatechangeEnergy useIndustry 30%Transport 30%FIGURE 1-ENERGY USE AND CLIMATE CHANGEBuilt environment 35%Other 5%buildings, and thereby contribute to a better environment. Therefore, the builtenvironment is an important focus area to contribute to the sustainability targets, statedby the European Union.ENERGY EXPENSES IN HOUSESThe large amount of energy use and material use is not the only concern in the builtenvironment. Increasing expenses for energy use in houses is another actual problemthat has to be solved in the near future.FIGURE 2 - DEVELOPMENT GAS PRICES (CORDEWENERSET AL, 2009)FIGURE 3 - DEVELOPMENT ELECTRICITY PRICES(CORDEWENERS ET AL, 2009)Increasing energy expenses is a significant and increasing social problem. During the lastdecades not only the use of energy increased, but also the price of energy increased. See8

figure 2 & 3. This results in increased energy expenses and thereby increased housingcosts. Scientists forecast a substantial increase of the energy prices in the near future. Inthe book “Energiebesparing en huurverhoging”, Weevers & Go (2009) predict that in thefuture, the price that occupants pay for the use of water, electricity and gas exceeds therental price.The current state of the energyperformance of social housing in theNetherlands shows the problem in thisLabels Dutch housing stock3%field. The energy performance of the totalhousing stock in the Netherlands is showedin figure 4. The energy performance of ahouse is represented by an energy label.16% 13%Label ALabel BLabel CLabel DThis label is a standard to show consumersthe economic, environmental friendly, and17%21%Label ELabel Fenergy saving performance of a house.Label G14%Hereby, „Label A‟ represents the best17%energy performance, and „Label G‟represents the worst performance. FigureFIGURE 4 – LABELS DUTCH HOUSING STOCK. SOURCE:4 shows that 64% of the total housingVROM-CIJFERS OVER WONEN WIJKEN & INTERGRATIEstock in the Netherlands scores energylabel D or worse. This situation is a large upcoming social problem for Dutch housingcorporations and their tenants. Low social classes of society mostly occupy houses with alow energy performance. Therefore, this is the first social class that will be confrontedwith the impact of increasing energy prices. Tenant interest organizations address theimprovement of the energy performance of houses prominently on the agenda for thediscussion with housing corporations. Also, the „Nederlandse Woonbond‟ has madeenergy savings one of the most important issues to be solved (Weevers & Go, 2009).OFFICESNext to the problems in the housing sector, also offices contend with an increasingproblem. More and more offices become unoccupied due to companies that move over tonew developed offices. Companies that move over, frequently focus on sustainability andthus an office with low energy use, to be prepared for the forecasted increasing energyprices in the future and to use their office as a display for their strategy and image.Also, the commercial value of sustainable buildings is higher compared to non sustainablebuildings. Research points out that the effective rent for sustainable buildings is higher,the premium is higher at sale, and the occupation of sustainable buildings is highercompared to non sustainable buildings. (Eichholtz, Kok & Quigley, 2008). This increasesthe amount of transitions towards sustainable offices and increases the problem ofunoccupied offices.Although the current sustainability problems for offices are actual and important, thisresearch focuses on the problems in the housing sector.THE TRANSITION PROCESSThe previous paragraph points out that the state of the current built environment causesserious problems for society. These problems can be reduced by improving thesustainable performance of houses in the Netherlands in a transition process. To increasethe pace of this transition process, there are three options.1. Demolition of existing houses and replace them by new development2. More new development3. Renovation9

Amount of housesIn the next three sections, the desirability of these three options are evaluated on thebasis of the principle people, planet, profit defined by Elkington (1997). This principle isdescribed in more detail in subparagraph 3.2.1, page 32.DEMOLITION AND NEW DEVELOPMENTThe first option is to demolish existing houses and replace them by new houses thatconsume less energy. This option is characterized by several disadvantages.The first disadvantage is that demolishing houses results in large waste streams and alarge demand for new materials. The current construction sector is estimated to generateapproximately 40% of all man-made waste (Sunnika, 2006). According to the WorldWatch Institute the entire global community will run out of raw building materials byapproximately 2030 if the current trend continues (Brown, 1990).The second disadvantage is that demolishing existing houses destructs capital. Thiscapital can be sub divided between human capital and capital as in value of the houseitself. The social structure that is inextricable connected to the built environmentrepresents a certain capital. This is demolished when existing buildings are replaced bynew buildings. Also the capital that is represented by the building itself is demolished.The third disadvantage is that demolishing houses contributes to the scarcity ofaffordable houses in the Netherlands and thereby will result in higher housing prices,what makes it more difficult for starters to enter the housing market. Lastly, the pace ofreplacement of the current builtenvironment is too slow to have asignificant influence on the energyuse and CO 2 emissions to meet therequirements of the EU targets in2020. Figure 5 shows the number ofbuildings that are demolished anddeveloped in the period 1995-2008in the Netherlands. The figure showsthat approximately 20.000 housesare demolished each year. Regardingthe fact that the current Dutchhousing market consists of about7.000.000 houses, it takes about350 years (=7.000.000/20.000) toreplace the total current housingstock in the Netherlands. However,FIGURE 5 - RENEWAL OF THE DUTCH HOUSING MARKET. SOURCE:CBS12000010000080000600004000020000this option also provides advantages. First, new development leads to an increasedsupply of a scarce good (houses with a higher energy performance). Secondly, the reuseof materials like roof tiles is easy to execute. Lastly, it is possible that the quality andesthetics of the existing houses is low in such a way, that renovation is not attractive toexecute. In this case, demolition and new development can be the most attractivealternative.MORE NEW DEVELOPMENTThe second option to speed up the transition process is to increase the pace of newhousing development on new locations. In the first place it seems to be an effectivesolution to increase the supply of houses with a higher energy performance because thismeasure can be used to increase the supply of affordable houses with a higher energyperformance, which is a scarce good. However, new development does not contribute toa better performance of the existing built environment. Next to that, this newdevelopment mainly causes a stream of occupants that move over from their old housesinto the new developed houses. This causes a large amount of unoccupied existinghouses. This amount of unoccupied houses results in attraction of occupants from thelower social classes to one region and in vacancy, which leads to a declining regionquality.01995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2006 2008Added housesDemolished houses10

RENOVATIONThe third option is large-scale renovation of the existing housing stock. Hereby, theexisting social structure and urban structure stays intact and there is only minor wasteproduced for the same end result as in case of new development. Also only a minoramount of new materials is needed, which takes the problem concerning depletion of rawmaterials into account. Therefore, renovation is less burdening for the environment thandemolishing and new development. (Klunder, 2005)In their research, Andeweg & de Jonge (2005) describe that in many cases renovation isalso attractive on the financial aspect. Renovation is an effective solution whichcontributes to a better energy performance of the built environment without demolishingsocial en urban structures. Next to that, it creates more affordable houses and therebyprevents the housing prices to increase more rapidly. Occupants of renovated houses donot suffer from enormous energy expenses. A disadvantage of this approach is that itrequires more organization effort because occupants must be involved in the process.Beside the intrinsic advantages, also the extensive period that is needed to replace thetotal housing stock with new buildings makes renovation as a possibility with greatpotential to contribute to the sustainability of the built environment in the Netherlands.Sustainable renovation is required to speed up the transition process and to achieve aless consumptive built environment in the Netherlands.Based on the elaborated options above, it can be concluded that it is impossible toprovide a one-sided determination of the best alternative to increase the pace of thetransition process. It depends on the situation, which of the three identified options is themost attractive one. The selection of the most attractive option should be based on adeliberation of characteristics of the situation and the advantages and disadvantages ofthe three possible options.Generally it can be stated that:- demolition and new development is attractive if it is impossible to renovate theexisting houses.- more new development is attractive if the situation allows it; currently, affordablehouses with a high energy performance are still scarce.- renovation is attractive if the existing houses are suitable for renovation and thereare no hurdles for the execution of the renovation project.SELECTING A SUSTAINABLE RENOVATION CONCEPTFrom the three options described in the previous paragraph, it appears that renovation ofexisting buildings can be a very attractive option to contribute to the transition processthat is required. This research focuses on this option.Regarding the increasing media attention and political activities for climate change andincreasing energy expenses, the conviction that improvement of the current builtenvironment is needed, significantly grows in time. More people and companies becomeaware of the importance and advantages of sustainable buildings and the possibility toapply effective sustainable renovation techniques to their houses.However, the question is: Which renovation techniques are effective and sustainable forwhich type of projects? This question demands the possibility to compare differentsustainable renovation measures or concepts with each other. The comparison ofdifferent concepts makes it possible for people and companies to make a well foundedchoice for the most attractive renovation concept, given their specific situation. Thisresearch focuses on the development of a model that can be used to determine andcompare the performance of sustainable renovation concepts.11

1.2 LOCAL COMPANY & WARMBOUWENLOCAL COMPANYThis research is executed at Local Company, Amsterdam. Local Company is specialized inthe (re)development of sustainable real estate. For the realization of sustainable quality,Local Company focuses on the combination of economical, technical and organizationalaspects.WARMBOUWENAs stated in the introduction, this research focuses on the development of a model thatcan be used to determine and compare the performance of sustainable renovationconcepts. In this research, this model is used to determine the sustainable performanceof “WarmBouwen”. WarmBouwen is a sustainable renovation concept, developed by LocalCompany and KBNG architects. More information about the sustainable renovationconcept WarmBouwen is provided in paragraph 5.1, page 59.The first application of WarmBouwen was at the renovation project of monument „DeTempel‟ in The Hague, the Netherlands. The renovation project „De Tempel‟ is analyzed inthis research by a case study. In this report, the reference „De Tempel‟ refers to thisrenovation project.12

2. RESEARCH DESCRIPTIONThis chapter elaborates the research structure of this thesis. The research structure isbased upon the book of Verschuren en Doorewaard (2005).2.1 PROBLEM DEFINITIONParagraph 1.1, page 8 provides an extensive elaboration of the problem definition of thisresearch. A summary of the problem definition is described below.Although it is clear that renovation is required and has a high potential for CO 2 reductionin the built environment, there is minor scientific knowledge about the aspects thatinfluence the performance of sustainable renovation concepts. Next to that, there isminor scientific knowledge about the relationship between the aspects that influence theperformance of sustainable renovation concepts.Local Company developed the sustainable renovation concept WarmBouwen.WarmBouwen is a potential attractive concept that can be applied for housing renovation.However, the sustainable performance of WarmBouwen is not validated.2.2 RESEARCH GOALThe goal of this research is to develop a performance evaluation model for sustainablerenovation concepts by identifying factors that influence this performance, and byidentifying the contribution and correlation of these factors on the performance ofrenovation concepts. Also, this research identifies factors of influence on the marketimplementation of innovative sustainable renovation concepts.The performance evaluation model will be used to evaluate the performance of threerenovation alternatives, and to analyze the relationship between the factors of influenceon the performance.This research is facilitated by Local Company, Amsterdam. This research provides LocalCompany with a performance evaluation of the innovative sustainable renovation conceptWarmBouwen. Also potential points of improvement for WarmBouwen are derived.13

2.3 RESEARCH QUESTIONSMAIN QUESTIONWhat are factors of influence on the life cycle performance of a sustainable renovationconcept?GENERAL SUB QUESTIONS1. What is sustainable renovation?2. What are factors of influence on the performance of a sustainable renovationconcept?3. What are factors of influence on the market implementation of an innovativesustainable renovation concept in the Netherlands?4. What is the composition of- and correlation between the identified factors ofinfluence?WARMBOUWEN SUB QUESTIONS5. What are the characteristics of WarmBouwen?6. What is the sustainable performance of WarmBouwen?7. What are improvements for the WarmBouwen renovation concept?2.4 RESEARCH MODELThis research consists of several steps and phases. Figure 6 shows the phases and stepsof this research.Expert interviewsQ1Q2Q1Q2Q5Literature studyExplorecharacteristics ofsustainability andsustainablebuildingLiterature studyExplorecharacteristics ofsustainablerenovationLiterature studyExpert interviewsModel 2Model 1Points of interestModel 3Q2Model 4Resultsanalysis&ModeldevelopmentExpert interviewsTesting modelon casesCase studiesResultsinterpretation&ModeloptimizationQ4, Q6, Q7EvaluateWarmBouwenConclusions &RecommendationsExplorecharacteristics ofWarmBouwenExpert interviewsQ3Q3Literature studyPoints of interestExploreimplementation ofinnovationsResultsanalysisPhase 1 Phase 2 Phase 3Phase 4Phase 5Exploration of theoreticalbackgroundFIGURE 6 - RESEARCH MODELIdentification and evaluationof points of interestModel developmentModel testing, optimization and applicationConclusionsChapter 3 Chapter 4Chapter 5Chapter 714

2.5 RESEARCH METHODOLOGYThis paragraph describes the research methodology. The research methodologyelaborates the research phases in more detail. Figure 7 presents the elaborated researchphases and the section of the report where results of these phase can be found.Phase Phase description Results provided in Pagessection1 Exploration of theoretical background chapter 3 20-442 Identification of points of interest paragraph 3.1paragraph 3.4 – 3.620-3136-443 Model development chapter 4 45-574 (1) Model testing and optimization - -4 (2) Model application chapter 5 58-785 (2) Conclusions chapter 7 83-88FIGURE 7 - RESEARCH PHASES AND RESULTS2.5.1 PHASE 1 - EXPLORATION OF THEORETICAL BACKGROUNDThe first phase of this research consists of a literature study and expert interviews aboutimportant subjects of this research.LITERATURE STUDYIn the first step of this research a literature study is executed to create a clear view ofthe general background and the occasion of this research. This first step is also executedto give more insight in the importance of this research. Information from websites,scientific articles, and scientific reports is used for the definition of the background.In the second step a literature study is executed to explore the concepts of sustainabilityand sustainable renovation of buildings, WarmBouwen, and the implementation ofinnovations. Several search engines like the online library of the University of Twente,Google Scholar, and Science Direct are used to gather scientific information about thesesubjects. Also study books are consulted. The goal of this literature study is to create aclear and comprising overview of the current scientific literature of the involved subjectsin this research. The results of this literature study are provided in chapter 3, page 20.EXPERT INTERVIEWSExpert interviews are executed to gather relevant information about the involvedconcepts of the research. These interviews are executed to contribute to the definition ofthe background of the research and to provide information about the research concepts.In the first phase five experts are interviewed. Two of these experts are developers ofthe WarmBouwen concept. These experts are selected to provide information aboutWarmBouwen, based on their knowledge of the WarmBouwen concept. The other threeexperts are interviewed to define the research background. An analysis of the currentmarket of sustainable energy in the built environment was the basis for the selection ofthese experts. Appendix B provides a list with the selected experts in phase 1.The goal of the interviews in this first phase of the research is to gain more insight in theproblems that play a role at the main research subjects. At the moment of theseinterviews, there was not a clear structure or research topic defined yet. Therefore, a listof important subjects was the basis of these interviews to make sure that the mostimportant subjects were discussed during the interviews.The end result of the first research phase is a structured research design that forms thebasis for the research.15

2.5.2 PHASE 2 - IDENTIFICATION POINTS OF INTERESTThe second phase of this research has two goals. The first goal is the identification andevaluation of factors of influence on the performance of sustainable renovation concepts.The second goal is the identification and analysis of factors of influence for the marketimplementation of innovative sustainable renovation concepts.IDENTIFICATION OF FACTORS OF INFLUENCEFor identify factors of influence on the performance of sustainable renovation concepts,existing evaluation models in the field of sustainability are analyzed and evaluated. Also,expert interviews are executed.SELECTION OF MODELSExisting sustainability assessment models are analyzed to identify factors that influencethe performance of sustainable renovation concepts. For the selection of analyzedmodels, the following selection criteria are defined:The existing model must be:- applied on large scale in the Netherlands- able to provide objective information- up-to-date- developed by a specialized agencyAs a result of these selection criteria, four models that are currently used for thedetermination of the sustainable performance of buildings are selected and analyzed.These models are listed in figure 8.ModelEPWBREEAMGPR GebouwGreencalcFIGURE 8 - ANALYZED MODELSDeveloped byDGMRBuilding Research Establishment (UK)W/E AdviseursSureacThe results of this model evaluation are provided in paragraph 3.4, page 36.SELECTION OF EXPERTSNext to the analysis of these four models, expert interviews are executed to create acomprising view on the factors that have an influence on the performance of sustainablerenovation concepts. For the selection of experts that are interviewed in this phase, thefollowing selection criteria are defined:The respondent must be:- a specialist on at least one of the factors that influence the performance ofsustainable renovation concepts. These factors of influence are: life cycle costs, lifecycle yields, environmental impact, quality, and energy performance- willing to share his/her knowledge, so that it can be used for this research- able to provide objective informationAs a result of the selection criteria stated above, seven experts are interviewed to gatherinput for the development of the model. Appendix A describes why these respondents areselected for an interview. Appendix B provides a list with the seven selected experts.The executed interviews were structured on the basis of a questionnaire, which iselaborated in advance of the interviews. The questionnaires concern general questionsabout relevant subjects and specific questions that are specified on the expertise and16

profession of the expert. The notes and results of these interviews are provided inappendix B.MARKET IMPLEMENTATIONThe second goal of this phase is the identification of factors that influence the marketimplementation of innovative sustainable renovation concepts. Therefore, a literaturestudy and expert interviews are executed. The results of the executed literature studyand interviews are provided in paragraph 3.1, page 20.LITERATURE STUDYThe literature study is performed to identify factors that influence the marketimplementation of innovative sustainable renovation concepts. Therefore, informationfrom websites, scientific articles, and scientific reports is used.SELECTION OF EXPERTSThe goal of the interviews with involved experts at the renovation project “De Tempel” isto identify barriers for the practical execution of the renovation concept and to identifyfactors that influence the practical execution of the WarmBouwen concept. To create acomprising view, experts that are involved as representative of different stakeholders atthe execution process of project “De Tempel” are interviewed. As a result of the goalstated above, three experts are selected and interviewed. Appendix B provides a list withthe selected experts.The executed interviews are structured on the basis of a questionnaire, which iselaborated in advance of the interviews. This questionnaire is specified on the expertiseand profession of the expert. The notes of these interviews are provided in appendix B.The result of the second phase of this research is a first version of the performanceevaluation model for sustainable renovation concepts. This concept model is presented infigure 17, page 31. In the model development process, information from the literaturestudy is compared with results from the expert interviews. The factors with an influenceon the performance of renovation concepts are integrated into one model.2.5.3 PHASE 3 - MODEL DEVELOPMENTIn the third phase, the results from the literature study, existing model evaluations, andexpert interviews are compared and evaluated. This phase results in the development ofthe final “performance evaluation model for sustainable renovation concepts”, which isdepicted and explained in more detail in chapter 4, page 45.2.5.4 PHASE 4 - MODEL TESTING AND OPTIMIZATIONIn the fourth phase, the applicability and completeness of the model and its integratedfactors are evaluated. This is done by applying the developed model on three selectedrenovation alternatives. For the determination of input parameters for this process, aliterature study, case studies, and expert consults are executed. The second goal of thisphase is the improvement and optimization of the model, based on insights from themodel application.MODEL TESTINGFor the application of the model, three alternatives for the renovation of a house areselected. One of the selected renovation alternatives is the WarmBouwen concept,because this is the renovation concept that is evaluated in this research. Chapter 5, page58 provides detailed information about the WarmBouwen concept. For the selection ofthe other alternatives the following criteria are defined.17

The renovation alternatives must:- point out whether is it sustainable and effective at all, to apply sustainable renovationmeasures- show the effect of applying WarmBouwen to a house. Thus show the differencebetween the current situation and the situation of WarmBouwen- show the difference between applying WarmBouwen and applying the current widelyapplied „standard‟ measuresBased on these criteria, the following alternatives are selected:1. No renovation. Details of this alternative are described in appendix C1.2. Standard renovation. Details of this alternative are described in appendix C1.DETERMINATION OF PARAMETERSFor the application of the model, many input parameters are determined. The literature,reports and product sheets that are used to determine the input for model application arelisted in appendix D.For determining the input parameters for the application of the model, several expertshave been consulted. The experts that have been consulted for determining the input ofthe model calculations are listed in appendix D.SELECTING THE EXPERTSFor the collection of valid input parameters for the model application, it is important thatthe consulted experts have specialist knowledge on the field of the subject. The consultedexperts that are listed in appendix D are all professionals and experts in the field of thesubject, they are consulted about. Most of these experts are consulted by telephone.CASE STUDIESThe goal of the case studies is to deliver input parameters for model calculations.Therefore the selection criteria below are defined for the selection of the cases.The case must:- be comparable with the situation in this research- be able to produce objective information- be recently executedAs a result of the stated selection criteria stated above, the following cases are selected:- “De Tempel” – Den Haag- “Krayenhoff” – UithoornFor the data collection at the case studies, a list of subjects is made on which detailedinformation is needed. The cases provide detailed information about exploitationcalculations and offers. Therefore, the cases provide useful input for the calculations.MODEL OPTIMIZATIONThe second goal of the fourth phase is the improvement of the model based on the modelapplication. For the improvement of the model, the input and output of the model areinterpreted and analyzed.The updated model is applied again on the three selected renovation alternatives. Theapplication of the updated model generates the output that is analyzed for the researchresults.18

2.5.5 PHASE 4 - MODEL APPLICATIONIn phase five the results from the model application on the three defined renovationalternatives in phase four are analyzed. Information about the model application anddata analysis is provided in chapter 5, page 58.DATA ANALYSISThe analysis of the data consists of the following steps:1. Analysis of the behavior of the performance of each renovation alternative due toscenario changes2. Correlation analysis between factors within the model3. Analysis of the composition of the output of each main model factor4. Analysis of the influence of boundary conditions on the output of each alternative2.5.6 PHASE 5 - CONCLUSIONSFinally, conclusions and recommendations are provided on the basis of the formulatedresearch questions. Chapter 7, page 83 provides the conclusions and recommendationsof this research.2.6 RESEARCH SCOPEIn this research, five main factors of influence on the life cycle performance areidentified. The extensive elaboration of the factor „life cycle yields‟ is outside the scope ofthis research. For the model application, the elaboration of this factor is executed with alimited level of detail, based on specialist knowledge.The aspect „life cycle costs‟ is used to determine the average yearly life cycle costs forinterior climate regulation of a house. If a house is occupied by tenants, these life cyclecosts will be partly at the expense of the tenants and partly at the expense of the owner,which can be a housing corporation or a real estate investor. At the determination of theperformance of a renovation concept on the aspect „life cycle costs‟, the distinctionbetween the parties that bear the costs is not taken into account. The problems thatarise from this issue are outside the scope of this research.The aspect „energy use of lighting‟ of a house, is outside the scope of this research. Theperformance of a sustainable renovation concept refers to the performance on the aspectof interior climate control of a house and the way a house is capable to cope withfunctional changes and adaptations.This research focuses on the renovation of houses. Although a lot of identified factors inthe developed evaluation model also account for the renovation of office buildings andother and utility buildings, the developed model may have its shortcomings for this typeof buildings.19

3. THEORETICAL BACKGROUNDThis chapter shows a critical literature review of relevant theory to answer the first threeresearch questions. The following research questions are answered in this chapter:1. What is sustainable renovation?2. What are factors of influence on the performance of a sustainable renovationconcept?3. What are factors of influence on the market implementation of an innovativesustainable renovation concept in the Netherlands?Paragraph 3.1 concentrates on research question 3 that is stated above. Paragraph 3.2 &3.3 concentrate on research question 1. Paragraph 3.4, 3.5, and 3.6 provide informationabout research question 2, which results in the identification of factors of influence on theperformance of sustainable renovation concepts. The identified factors of influence areprocessed in a first concept of the performance evaluation model, which is presented inparagraph 3.7, page 44. Figure 9 provides an overview of the four research componentsof this research that provide input for the model development. Paragraphs 3.4, 3.5, and3.6 put together the research components 1 & 2 (see figure 9).1. Literature study2. Evaluation existing tools3. Interviews4. Model testingModeldevelopmentFIGURE 9 - RESEARCH COMPONENTS FOR MODEL DEVELOPMENTModelapplication3.1 IMPLEMENTING AN INNOVATIVE RENOVATION CONCEPTThis paragraph provides information about factors of influence on the marketimplementation of an innovative sustainable renovation concept. This information is usedto answer research question 3, which is stated below.3. What are factors of influence on the market implementation of an innovativesustainable renovation concept in the Netherlands?Subparagraph 3.1.1 elaborates aspects of adoption and implementation of innovations.Subparagraph 3.1.2 elaborates legislation and rules that are relevant at implementing asustainable renovation. Subparagraph 3.1.3 evaluates innovative concepts that could becompetitive concepts of WarmBouwen. Subparagraph 3.1.4 describes the technicalfeasibility of the concept. Lastly, the aspects „organization‟ and „process‟ that are requiredto facilitate implementation of the WarmBouwen concept are elaborated in subparagraph3.1.5.3.1.1 ADOPTING AND IMPLEMENTING AN INNOVATIONThis subparagraph elaborates aspects that play a role at the adoption andimplementation of innovations.20

HUMAN BEHAVIORIn his report, Hoppe (2009) describes that the human perception of short term costs andlong term profit forms an important problem in recognizing environmental danger. Toexplain this problem, scientists define different explanations.Hoppe describes that environment-psychological and -economical insights explain thathumans are mentally unable to pick up signals of deterioration and simultaneouslyprocess these signals to create measures that prevent the consequences from occurring.There is coherence between this process and the overestimation of the individual intereston the short term compared to the common interest on the long term. (Hoppe, 2009)SYSTEM CHANGEOne of the problems by implementing innovations is the current system, which can leadto a system „lock-in‟. Due to a process of path-dependability rules, policy, and practiceshave been tuned on certain concepts in history. This process causes the „lock in‟ position,which leads to a situation whereby alternatives of the system evoke a lot of resistance.This „lock-in‟ can be considered as a protection mechanism of a dominant acceptedconcept against alternative concepts. (Hoppe, 2009)To break through this „lock-in‟, a change process has to be started. According toDieleman (1999), change processes depend upon three factors: confrontation, reflection,and experiment and common learning.In the declaration of system change, two dimensions can be distinguished.1. The extend into which the system changes2. TimeChanges can be declared by the ensemble of layers in the social system: the micro-,meso- & macro level. On micro level there are technological niches. The meso level is thelevel that is determined by the presence of socio-technical regimes. The macro level isthe socio-technical landscape. This level is the broad exogenous context of a socialsystem (Hoppe, 2009). Next to the three different socio-technical levels, there are alsofour different phases which are relevant for innovative concepts before a system changetakes place. These phasesare: the pre developmentphase, the lift off phase, theacceleration phase, and thestabilization phase. In the predevelopment phase, there isstill a mismatch between theinnovative concept andeconomical, social en politicalsystems. The concept is stillnot fully developed. In the liftoff phase, the innovativeconcept is applied in littlemarket niches that providesources to stimulate furthertechnical specialization. Inthe acceleration phase, thebreakthrough of the concept takes place. In the stabilization phase the innovativeconcept changes the current socio technical regime. Figure 10 shows a graphicalpresentation of the system change in time within a social system.ADOPTION OF INNOVATIONFIGURE 10-DEVELOPMENT PHASES, (DIELEMAN, 1999)Next to system change, the adoption of innovations by customers in time is important.To say something about adoption of innovations by customers, Rogers (2003) has put up21

a system in which members of a social system are classified based upon their willingnessto accept innovative concepts.This principal is defined as thedifferences in the time thatindividuals within a socialsystem require to acceptinnovative concepts. Figure 11depicts the classification ofRogers between groups in asocial system and the timethey need to acceptinnovations. Innovators areadventurous people that areinterested in the newesttechnological possibilities. Theearly adopters are people thatare almost as willing as theinnovators to acceptFIGURE 11-TIME UNTIL ACCEPTANCE OF INNOVATION (ROGERS, 2003)innovations. However, the early adopters have a business interest in accepting theinnovation. The early majority is a group where the modal members of a social grouptake place. The late majority will accept an innovative concept if people from the earlymajority have already accepted the innovation. The laggards are the group members thataccept the innovations lastly (Rogers, 2003).Next to the classification on characteristics of groups of customers, Rogers (2003) alsorecognizes five characteristics of innovations that play a role at the adoption ofinnovations. These intrinsic characteristics of innovations that influence an individual‟sdecision to adopt or reject an innovation are (Rogers, 2003):- Relative advantageThe relative advantage is the perceived improvement of the innovation over existingsolutions in terms of economic or technical benefits or other advantage-producingperspective. The most important advantage is the perception of personal advantage.- CompatibilityThe compatibility is a measure of the suitability of the innovation to its use, both in atechnical and a social sense. Technical compatibility reflects the appropriateness of aninnovation to its intended technical system. Social compatibility reflects the suitabilityof the innovation and its use to the potential adopter‟s use process and values.- ComplexityThe complexity of an innovation reflects the degree to which the innovation is difficultand complicated to understand or use. Innovations that are easy to understand aremore likely to be adopted.- TrialabilityThe trialability refers to the extent to which adopters can experience, try or perceivethe innovation before making the commitment to adopt. A high trial ability reducesrisk perception and thereby increases the rate of adoption.- ObservabilityThe observability of an innovation refers to the transparency of the advantages of theinnovation to potential adopters. Observability also relates to the degree to which thebenefits can be communicated to others.Another factor that can be advantageous for the adoption of an innovation is the networkeffect or network externalities (Liebowitz & Margolis, 1997). The network effect refers tothe effect that one user of a good or service has on the value of that product to otherpeople. In case of a positive network effect, the value of a product or service increases asmore people use it. A classic example of a positive network effect is the telephone. Themore people own telephones, the more valuable the telephone is to each owner. In case22

of negative network externalities, more users of a product cause network congestion(Liebowitz & Margolis, 1997).CONCLUSIONSRegarding the phases of Dieleman, the WarmBouwen concept is currently in the lift-offphase. The concept is applied at the renovation of “De Tempel”. For „Local Company‟, thedeveloper of the concept, the focus should be on the execution of more projects and onthe evaluation of the concept to extend the field of application, to improve the concept,and to gain publicity.Regarding the scale of Rogers, the WarmBouwen concept is arrived at the innovators, butthe early adopters are still to come. For large market implementation, more projectsshould be executed and more publicity has to be gained.The characteristics of WarmBouwen that play a role in the adoption of the concept aredescribed below.Relative advantage: The WarmBouwen provides a large relative advantage to the currentsituation of sustainable performance of houses in the Netherlands. Also the relativeadvantage to a standard renovation is significant.Compatibility: WarmBouwen has a low performance on the aspect compatibility. Theconcept is not compatible to the existing systems in houses, which makes the applicationof the concept a rather radical process.Complexity: The complexity of the WarmBouwen concept is high. The techniques that areused are hard to understand and have different characteristics and principals than peopleare currently used to.Trialability: WarmBouwen scores low on the adoption factor trialability. The concept isapplied in the Netherlands in minor amount and it is hard to experience the concept onalternative ways. This makes is hard for potential users to try the concept.Observability: It is easy to appoint and explain the advantages of the WarmBouwenconcept over the current methods for interior climate control in houses. Therefore,WarmBouwen scores high on the adoption factor observability.The WarmBouwen concept is not subject to network externalities.3.1.2 LEGISLATION & RULESNext to characteristics of customers and characteristics of the innovation itself,accounting legislation and rules also play an important role at the adoption ofinnovations. Therefore, this paragraph explores relevant legislation and rules thatinfluence the implementation of sustainability measures on dwellings in the Netherlands.LEGISLATION AND RULESIn the Netherlands, rules concerning the rental price for houses are dispersed amongstseveral legislations and rules. Important provisions from these legislation and rules areconsidered in the subparagraphs of this section. Relevant legislation and rules are:(Weevers & Go, 2009)- Uitvoeringswet Huurprijzen Woonruimte (UHW)This law regulates the determination of the rental price. Regulations that arebased upon the UHW are: “Besluit Huurprijzen Woonruimte” (BHW), “WoningWaarderings Stelsel” (WWS) & “Uitvoeringsregeling Huurprijzen Woonruimte”(UrHW)- Burgerlijk Wetboek (BW)The articles 237 and 246-265 of book 7 regulate aspects as increasing rentalprices, increasing rental prices after house improvements, and rental pricedetermination.23

- Besluit Beheer Sociale Huursector (BBSH)This law determines the core activities of the housing corporations.- Wet op het Overleg Huurders Verhuurder (WOHV)This law regulates the dialogue between tenants and owners about policy aspects.WONINGWAARDERINGSTELSEL (WWS)The WWS determines the maximum rental price that housing corporations can ask forsocial houses. The maximal rental price is determined based upon points that areattributed to a house. These points are attributed based upon the quality of the houseand its environment. However, in the current WWS, an investment in energy savingtechniques leads to a limited number of extra points. The WWS discourages aninvestment in energy savings measures. This is a restriction in the policy regarding theencouragement of energy saving measures.Another restriction of the WWS is that the total thermal insulation of a house can lead toa maximum of 15 points. As a result, housing corporations are discouraged to applysustainability measures to their envelope (Weevers & Go, 2009).Currently, a new WWS is developed and will be implemented in 2011. This new WWScaters to the current problems that arise from the WWS, regarding the implementation ofsustainable renovation measures.BURGERLIJK WETBOEK (BW)According to the BW rental prices of houses can be increased once a year. Hereby, the“Minister of VROM” determines an average and maximum percentage of increased rentalprices. However, next to this yearly rental price adaptation, the landlord is alwaysallowed to increase the rental prices due to implemented improvements of the house,such as energy saving measures.The BW does not restrict the implementation of energy saving measures directly. For arenovation project there are two limitations stated by the BW:- The increased rental price may not be higher than what is required for theinvestment, with reference to a basic yearly mortgage and a reasonable write-offperiod.- The rental price may not exceed the WWS.If ten houses or more are renovated at the same time, the renovation project is classifiedas renovating a complex. In this case at least 70% of the tenants have to agree with therenovation plans. Tenants are obliged to agree if the landlord gives a reasonable proposal(Weevers & Go, 2009).BESLUIT BEHEER SOCIALE HUURSECTOR (BBSH)Housing corporations in the Netherlands have to do with the BBSH. An important task ofhousing corporations is to supply appropriate housing to people from the lower socialclass with priority. Also the housing corporations should take care of the fact that tenantsapply for the rental surcharge from the Dutch government. The BBSH maximizes theaverage yearly increase of rental price. However, for the calculation of this averageincrease of rental price, the increase of rental price due to house improvement and rentalharmonization is not included (Weevers & Go, 2009). As a result, housing corporationsare discouraged to invest in energy saving measures in their buildings.RENTAL PRICE AND RENTAL SURCHARGEThe system of rental surcharge in the Netherlands, formerly known as rental subsidy, hasthe goal to support households with a low income in the rental costs. The rentalsurcharge depends on the income of a household. Dependable upon the age andcomposition of a household, the income boundary lays between 20.000 and 29.000 euro.The right on surcharge and the height of the rental surcharge depends upon the followingfactors: (Weevers & Go, 2009)24

- Rental price of the house- Composition of the household- Joint taxable income- Joint assetsUntil 2008, the municipality had to give consult about the suitability of a new house, if atenant subscribed for a new accommodation with a rental price above the reductionboundary. (The reduction boundary is the maximum rental price whereby tenants canapply for the rental surcharge). This suitability test has been abolished since 2008, whichmakes it possible for households to be eligible for a house with a rental price that isabove the accounting reduction boundary, without losing the right on rental surcharge.The abolishment of the suitability test gives housing corporations the possibility to investin energy savings measures, because they can raise the rental price of the houses,without the risk that the right on rental surcharge for tenants is in danger.For current tenants there is no danger. Even if the new rental price, after implementationof energy saving measures, gets higher than the maximum rental boundary for rentalsurcharge, the right on rental surcharge remains (Weevers & Go, 2009).PRIVATE SECTORIn the private sector there are fewer limitations in the field of legislation and rules. Thegovernment in the Netherlands tries to stimulate investments in energy savingsmeasures in the private sector by applying subsidies for these investments. Also the„Groenfinanciering‟ is a governmental measure to stimulate investments in energy savingmeasures. The „Groenfinanciering‟ gives discount on a loan, in case the loan is used toimprove the energy performance of a house.A limitation for the application of sustainable renovation can be the commission forprosperity and the commission for monuments. Some houses are classified as amonument. In that case the law for monuments applies. The law for monumentsprohibits the application of measures that change the esthetics of a building. This canform a problem by executing energy saving measures.The commission for prosperity is a commission that is appointed by the city council andconsults the municipality in the field of esthetics of a building and to what extend thebuilding suits in its direct environment. In case of a sustainable renovation it is possiblethat the exterior of the building changes. If the building is part of a protected area, thiscan result in the fact that the renovation of the exterior is prohibited based on thisaspect.CONCLUSIONSLaws and regulations that apply for the rental sector can form hindrances for theapplication of energy saving measures to houses. The current BBSH and the WWSdiscourage housing corporations in investments in the field of energy savings measures.In the private sector, laws en regulations rarely form a problem for the investments inenergy saving measures. Only hindrances can come up from the commission forprosperity and the law for monuments.3.1.3 ALTERNATIVESThis subparagraph provides insight in possible competitive concepts for WarmBouwen. Adescription and evaluation of the competitive concepts is provided in appendix J. Thisevaluation provides information about the viability of the WarmBouwen conceptcompared to other possibilities for the sustainable renovation of houses. Figure 12provides an overview of the performance evaluation of competitive concepts ofWarmBouwen.25

StandardrenovationPassivesolar designPassivehouse Earth houseWarmBouwenProgress on system change process (Dieleman) + +/- +/- +/- +/-Current adoption rate of innovation +/- - - - --Relative advantage +/- + ++ ++ ++Compatability + + +/- + +/-Complexity + + - + +/-Trialability - - - - -Observability +/- + + + +Suitability for renovation ++ -- -- -- +FIGURE 12 - PERFORMANCE EVALUATION COMPETITIVE CONCE PTS OF WARMBOUWENCONCLUSIONCurrently, the standard renovation measures that are widely applied in the Netherlandsare the most important competitor for WarmBouwen. This research points out that thelife cycle performance of the WarmBouwen concept is better than the life cycleperformance of a „standard renovation‟ concept. WarmBouwen scores better than thestandard renovation concept on the adoption factors relative advantage andobservability. The standard renovation concept scores better on the adoption factorscompatibility and complexity. The score on trialability is considered to be equal. However,the standard renovation concept has already made more progress in the adoptionprocess, which provides an advantage compared to WarmBouwen.The evaluation of competitive innovative concepts points out that current innovativeconcepts are mainly useful for new development and are less useful as a renovationconcept. The score on the adoption factors and the current position in the adoptionprocess of WarmBouwen is equal to the other evaluated innovative renovation concepts.3.1.4 TECHNICAL FEASIBILITYThis paragraph elaborates the technical feasibility of the WarmBouwen concept. The firstsection provides information about the constructive feasibility. The second section goesinto detail on the soil conditions that are required for the successful application of anaquifer. The third section addresses the scaling that is required, to make WarmBouwenapplicable.CONSTRUCTIVE FEASIBILITYParagraph 5.1 goes into detail on the elements that are used in the WarmBouwenconcept. The table below addresses and evaluates used techniques with regards to theconstructive feasibility of WarmBouwen.TechniqueAquiferHeat pumpAquiferouspackageEvaluationCurrently, aquifers are applied on large scale in new development projects in theNetherlands. The aquifer technique is technical feasible and in most places in theNetherlands applicable. A renovation project does not hinder the applicability ofthe aquifer. The next section elaborates the geographical applicability of anaquifer in more detail.A heat pump is applied on large scale in the Netherlands. The technical concept isdeveloped to a mature technique. A heat pump is applicable in renovationconcepts. However, a dwelling has to provide enough space to store the heatpump.The technique that is used for heating and cooling the dwelling is largely appliedas floor-, wall- or ceiling- climate regulation in renovation- or new developmentprojects. Currently, this technique is applied in combination with an aquifer and aheat pump but not with the purpose to harvest energy in the facades. However,this does not influence the applicability of the technique. Based on the fact thatthis technique is already applied on large scale in the Netherlands, this techniqueis considered to be applicable as a renovation technique.26

During the execution of this research, the WarmBouwen concept is successfully appliedas a renovation concept at the renovation of “De Tempel” in The Hague. This subscribesthe statement that the concept is constructively feasible. In an interview, the maincontractor of the project “De Tempel” states that his company took responsibility for theWarmBouwen concept for the whole life cycle of the project, because they are confidentabout the constructive performance and feasibility of the concept.SUITABILITY OF THE SOILTo apply an aquifer effectively, the soil below a project site must be suitable for anaquifer. The soil has to contain one or more layers that are impenetrable for water. „IFTechnology‟ and „TNO‟ have made an analysis in 2001, that describes the suitability ofthe soil in the Netherlands with reference to an aquifer. Appendix K presents the resultsof this analysis. The map shows that the soil in the Netherlands is nearly everywheresuitable for an aquifer. This leads to the conclusion that an aquifer is almost alwaysapplicable in the Netherlands and therefore does not hinder the feasibility andapplicability of the WarmBouwen concept.An alternative for the aquifer are soil loops. These loops differ from an aquifer becauseaccumulation of heat and cold is not possible. With soil loops, only exchange oftemperature with the soil is possible. The applicability of soil loops depends on theamount and current velocity of the groundwater. Although soil loops are an alternativefor an aquifer, they are outside the scope of this research.SCALEFor a cost effective exploitation of an aquifer, the scale of a project must be sufficient. Inthis research, the case “Krayenhoff” is analyzed. The scale of this project was 121dwellings. For application in the housing sector, a scale of approximately 100 dwellings isneeded for an aquifer. However, the minimal scale for a mono source aquifer is 30apartments. (www.nveo.nl)CONCLUSIONSThe concept WarmBouwen is technically feasible. The concept makes use of acombination of proven concepts. The analysis of the suitability of the soil in theNetherlands points out that an aquifer is applicable almost everywhere in theNetherlands. For the cost effective exploitation of an aquifer, a minimal scale is required.An aquifer requires a minimal scale of about 100 dwellings. If a mono sourced aquifer isapplied, a minimal scale of 30 apartments is sufficient for a cost effective exploitation.3.1.5 PROCESS & ORGANIZATIONA technical feasible concept is not the only requirement for the successful implementationof WarmBouwen in the renovation market in the Netherlands. Also, an effective processis needed to facilitate the successful realization of a project. This paragraph indentifiesthe stakeholders of a renovation project and the role of these stakeholders in the firstsubparagraph. The second subparagraph compares the process and project organizationof WarmBouwen with a conventional renovation project.STAKEHOLDERSIn this section the possible stakeholders of sustainable renovation projects are identifiedand the role of these stakeholders in a renovation project is described. Also, informationis provided about the required focus at involved stakeholders to implement sustainability.In the report “Procesmapping in bouwprocessen”, Morssinkhof (2007) identifies thefollowing possible stakeholders in new development construction projects.27

Central GovernmentProvinceGovernmental water agencyMunicipalityProsperity agencyLandownerDirect local residentsOther involved residentsFuture userProject developerArchitectContractorConstructorConsultantsFinancial consultantEnvironmental organizationsSubsidy distributorThe stakeholders in a renovation project are considered to be the same as thestakeholders in a new development project. The list above describes the possiblestakeholders in a renovation project. Appendix V describes the role and the requiredfocus of involved stakeholders in a renovation project for the implementation ofsustainable renovation applications.PROCESSRenovation of the current built environment has a high potential in the field of energysaving and CO 2 reduction. However, the integration of energy- and sustainability aspectsin the current built environment is not applied as frequently as desired. Experiences fromthe Dutch government point out that integration of sustainability aspects in the earlyphases of a renovation process can be advantageous for the implementation of theseaspects (Hoppe, 2009). Apparently, the process has an influence on the amount ofinnovative sustainable measures that are applied.This subparagraph compares the conventional renovation process with a process that isrequired for the successful execution of innovative projects. For this comparison, insightsfrom the case “De Tempel” and insights from experts interviews results in conclusionsabout the process that is most suitable for a „WarmBouwen renovation project‟.CONVENTIONAL RENOVATION PROCESSPHASESTenderProgramDesignConstructionAfter concerns / use /maintentancePROCESSESSubscriptionDialogueSelection of partiesInitiativeFeasibilityProject definitionSpatial programPreliminary DesignDefinitive DesignTechnical DesignDrawingsPrice and forming contractConstruction DesignConstruction -ManagementCompletionUsage/garantuee/ afterconcernsUsage / MaintenanceRenovation /redevelopmentDemolishFIGURE 13-TRADITIONAL RENOVATIONPROCESS (POEL, HUTJES & TIEKSTRA,2007)In the report “Innovatieve totstandkomingsprocessen inde woningbouw”, Poel, Hutjes & Tiekstra (2007)describe the traditional renovation process as known inthe Netherlands. Figure 13 provides a graphicaloverview of this process.Poel, Hutjes & Tiekstra (2007) describe that thetraditional renovation process leads towards problemsfor the integration of sustainability measures into adesign. Especially in the design process, the aspectenergy and sustainability is considered to be notimportant enough. As a result, this aspect is not takeninto account in an early phase. The consultant thatattends to interests from sustainability point of viewgets involved in a later phase. In practice this leads to aseparation between the constructive and architecturaldesign, and the design of the installations. Especially forrenovations it accounts that the long term strategicpolicy is not given enough attention. As a result,aspects as comfort, air quality, and sensation of thehouse are not important enough during the process.Also the changes in process phases lead towardsefficiency losses. The separation of disciplines andphases also lead towards a separation in expertise.Therefore, involved parties as the architect and the28

installation technical advisor pull back on their field of expertise and exhibit risk avoidingbehavior. Next to that, the organization structure does not stimulate integration betweeninvolved parties. (Poel, Hutjes & Tiekstra, 2007).The traditional design process is characterized by a mainly linear structure. Thesuccessive components of the processes in the different phases do not provide space foran adequate optimization of the design. Optimization afterwards is in most cases onlypartly possible and leads toward high costs. Figure 14 gives a graphical overview of thetraditional design process.FIGURE 14-TRADITIONAL DESIGN PROCESS (POEL, HUTJES & TIEKSTRA, 2007)Since around 1992 there has been attention for the necessity at radical renovationprojects, to come to an improved integration of energy- and sustainability measures.Research on this subject points out that integration of energy- and sustainabilitymeasures in an early phase of the renovation process is advantageous for effectiveimplementation.Current experiences from various national and international projects developed theinsight that: (Poel, Hutjes & Tiekstra, 2007)- An integrated approach should broaden itself to all aspects of building, includingenergy- and sustainability aspects.- Realizing an integrated approach requires an adapted and suitable organizationalstructure, as well as adapted and suitable responsibilities within this organizationalstructure.- Next to knowledge and expertise, also the attitude and skills of involved parties in thedesign team are important.INNOVATIVE INTEGRATED PROCESSThe previous paragraph shows that the traditional renovation process leads towardsproblems for the implementation of sustainability measures in the design. For successfulimplementation of these measures another process is required to facilitate the project.An integrated process does facilitate the implementation of innovative concepts andsustainability measures.An integrated design process is characterized by a connection of design cycles which areseparated by testing moments. This results in a process, whereby the required expertiseof specialists is brought into the project at the right phase of the process. This integratedapproach also takes a broad scale of possibilities into consideration from the beginning ofthe process. In the integrated process it is very important to test progress of theprogram of requirements during the process. The program of requirements changesbased upon insights that come up during the process. In an integrated process, there is adynamic program of requirements. (Poel, Hutjes & Tiekstra, 2007)Figure 15 gives a graphical overview of the integrated design process.29

PHASESTenderProgramDesignConstructionPROCESSESProposal and selectionInitial thoughts, analysisTesting feasibilityprogram of requirementsPreliminary Design cycleConceptual Design CycleIntegration of componentsCoordinatingMateralisationContracting, bargainingExecution aspectsRealizationQuality controlReportmomentsFigure 15 shows that there is a decisionmoment between each change of phase inthe process. These decision moments arebuild in, to check the results with theprogram of requirements. These decisionmoments are logical report moments,whereby approval can be given about thecompleted phases and decisions can bemade for the upcoming phases. If possible,the program of requirements can be changedon these moments. This results in a dynamicprogram of requirements.Also the design phases of an integratedprocess differ from the design phases in atraditional process. Figure 16 gives agraphical overview of the design phases ofan integrated process.Informing and trainingusersAfter concerns / use /maintentanceMaintenance, monitoringand optimizationRevision/re-orgnization= Moment of decisionFIGURE 15-INTEGRATED RENOVATION PROCESS(POEL, HUTJES & TIEKSTRA, 2007)Dynamic program of requirementsTest Test Test TestDesigncycleDesigncycleDesigncycleFIGURE 16-INTEGRATED DESIGN PROCESS (POEL, HUTJES & TIEKSTRA, 2007)CASE STUDY DE TEMPELA case study of case „De Tempel‟ is executed to analyze the differences andcorrespondences between theory and practice. The most important identifiedcharacteristics of the case study of „De Tempel‟ are stated in the bullets below.- Functional and dynamic requirements defined the program of requirements- Aspects as comfort and sustainability were addressed at the start of the designprocess- Involved parties experienced another process than they were used toDuring interviews, involved stakeholders at „De Tempel‟ stated that:- their standard procedures do not correspond with the situation at De Tempel- flexibility was required from the contractor into large extend, due to ongoing changesin the design and due to the absence of accurate drawings of the changes that havebeen made in the building during the last 100 years.- a traditional organization structure would have caused major delays in this project- the constructive- and installation technical aspects were highly integrated with eachother in this project. Therefore, a traditional process and organization was impossibleto hold on to.30

CONCLUSIONThe process at case „De Tempel‟ corresponds best with the innovative integrated process.Therefore, the innovative integrated renovation process is the most suitable process forthe execution of a WarmBouwen renovation project.3.1.6 CONCLUSIONThe five subparagraphs of paragraph 3.1 provide information about factors of influencefor the market implementation of innovative sustainable renovation concepts in theNetherlands. Figure 17 provides a model that integrates all the identified importantaspects.Implementing aninnovativesustainablerenovationconcept in NLSystemchangeprocessAdoption ofinnovationLegislation &rulesProcess &organizationTechnicalfeasibilityMainfactorsLevel of changePhasesCharacteristics ofcustomersCharacteristics ofinnovationBBSHWWSBWStakeholdersProcessConstructivefeasibilityExternal factors1 st levelsubfactorsMicrolevelInnovatorsScaleMesolevelMacrolevelEarly adoptersEarly majorityLate majorityGeographicalcharacteristicsLaggards2 nd levelsubfactorsPredevelopmentRelative advantageLift offCompatabilityAccelerationComplexityStabilizationTrial abilityObservabilityFIGURE 17 - IMPLEMENTATION MODEL FOR INNOVATIVE SUSTAINABLE RENOVATION CONCEPTS IN NLPERSONAL VIEWIn this section my personal view on the aspect market implementation is described.In my opinion, the foundation for a successful market implementation and adoption ofthe WarmBouwen concept consists of social, environmental and financial advantages ofthe concept, compared to the current situation and other concepts. This research showsthat WarmBouwen provides these advantages. However, the advantages on these fieldsare not sufficient for large scale adoption and implementation of the concept. I think thattrust and confidence in the WarmBouwen concept of real estate owners as housingcorporations and real estate investors/developers is crucial for adoption andimplementation. To gain trust and confidence at owners, marketing and referenceprojects are essential. The marketing and references must be powerful enough to temptowners to break with existing practices, partners, relations and interests. Publications,expert meetings, and presentations are examples of activities which can be used to gainpublicity for the WarmBouwen concept.31

3.2 SUSTAINABILITYThis paragraph describes the principles of sustainability and a sustainable building.3.2.1 SUSTAINABILITY AND SUSTAINABLE DEVELOPMENTWhen sustainability and sustainable development is discussed, one of the first questionsthat comes to mind is: “What is sustainability?” This paragraph elaborates differentviewpoints of sustainability.The dictionary provides several meanings for the word “sustain”. The main ones are to“maintain”, “support”, or “endure”. Since around 1980, sustainability has been usedmore in the sense of human sustainability on planet earth. This resulted in the followingdefinition:“Sustainable development is development that meets the need of the present withoutcompromising the ability of future generations to meet their own needs.”This definition is the most frequently referred to, and has been established by the UNWorld Commission on Environment and Development report, also known as theBrundtland report, „Our Common Future‟ in 1987.Sustainability terms and their definitions and interconnections are crucial forunderstanding sustainability, and for better communication in the process of moving oursocieties toward sustainable development (Glavic & Lukman, 2006). Glavic and Lukman(2006) state that each term has its own definitions and features, but it is difficult toisolate one term from the other terms, because the terms form an interconnectedsystem.Glavic and Lukman state that sustainable systems introduce interconnections between:- Environmental protection,- Economic performance, and- Societal welfareThese concepts of Glavic and Lukmancorrespond strongly with the principle of people,planet, profit that was introduced by JohnElkington in 1997 (figure 18). Acccording toElkington, these three elements should beharmoniously combined with each other. If thereis no harmony between these three elements,the underexposed elements suffer from theoverexposed elements.FIGURE 18 - PEOPLE-PLANET-PROFIT (ELKINGTON,1997)3.2.2 SUSTAINABLE BUILDINGSNow the concept of sustainability and sustainable development is explored, the conceptof sustainable buildings is described.According to the U.S. Environmental Protection Agency (EPA) (see also www.epa.gov) agreen or sustainable building is the practice of creating and using processes that areenvironmentally responsible and resource-efficient throughout a building´s whole lifecycle. This practice expands and complements the classical building design concerns of:- Economy- Utility32

- Durability- ComfortThe EPA states that green buildings are designed to reduce the overall impact of the builtenvironment on human health and the natural environment by:- Efficiently using energy, water, and other resources- Protecting occupant health and improving employee productivity- Reducing waste, pollution and environmental degradationKats (2003) states that green or sustainable buildings use key resources like energy,water, materials, and land much more efficiently than buildings that are not sustainable.Besides that, Kats states that sustainable buildings are cost-effective, saving taxpayersmoney by reducing operating- and maintenance costs, and lower utility bills.Sustainable buildings increasingly comply with the aspects (Kats, 2003):- Environment- Resources & energy consumption- Impact on people (quality and healthiness of work environment)- Financial impact (cost-effectiveness from a full financial cost-return perspective)- The world at large (a broader set of issues, such as ground water recharge and globalwarming, that a government is typically concerned about)The statements of Kats indicate the broadness of the concept of sustainable buildings.There are various fields on which sustainability can be achieved. The fields ofsustainability that are taken into consideration mainly depend on the context of a project.Kats (2003) also states that sustainable buildings have larger financial advantages,especially from a life cycle point of view. In the next paragraph, advantages ofsustainable buildings are described.3.2.3 ADVANTAGES OF SUSTAINABLE BUILDINGSThe advantages of sustainable buildings refer to different fields of impact. Therefore, theadvantages of sustainable buildings are divided into three fields of impact: economicadvantages, environmental advantages, and social advantages.The economic advantages of sustainable buildings are: (Lockwood, 2006); (Elkington,1997); (www.usgbc.org)- lower overhead costs- cost competitive in building design process- reduced operating costs- reduced maintenance costs- reduced replacement costs- enhanced asset value and profits- optimized life cycle economic performanceIn the report „Doing well by doing good?‟, Eichholtz, Kok and Quigley (2008) provideevidence on the economic value of sustainable buildings in the commercial sector. In thisresearch 694 green buildings are compared with 7489 other office building near these694 identified green buildings on the aspects of rental rate, occupation and salepremium. The conclusions of this report are presented in the bullets below.The economic advantages of sustainable commercial real estate are: (Eichholtz, Kok &Quigley, 2008)- 8.5% higher effective rent- 16.8 % higher premium at sale- 2-3% higher occupation33

Although these conclusions account for commercial real estate in the U.S.A., it can beconcluded that sustainable real estate provides significant economic advantagescompared to non-sustainable real estate.The environmental advantages of sustainable buildings are: (Lockwood, 2006);(Elkington, 1997); (www.usgbc.org)- enhanced and protected ecosystems and biodiversity- improved air and water quality- reduced solid waste- conserved natural resources- less site disturbance- reduced amount of resource extractionThe social advantages of sustainable buildings are: (Lockwood, 2006); (Elkington, 1997);(www.usgbc.org)- Improved indoor air quality, natural day lighting and user comfort, which results in• greater employee productivity• less absenteeism• stronger employee attraction and retention- Local economies benefits, because emphasis is placed on purchasing locally producedgoods and servicesAccording to Green Advantage (www.greenadvantage.org), the cumulative effect oflarge-scale green building can have enormous benefits for the community, nation, andplanet. These benefits are:- reduced energy dependence- fewer power plants- cleaner air- healthier environment- increased sustainability- improved public health- decreased susceptibility to disasters3.3 SUSTAINABLE RENOVATIONThis paragraph describes the concept of sustainable renovation.3.3.1 DEFINITION OF RENOVATIONThe dictionary defines renovation as the process of making a house or district inhabitableagain due to radical alteration. Renovating is defined as adapting or modernizing.According to the website of the Rijksoverheid (www.rijksoverheid.nl), renovation is equalto house improvement and comprises the partly renewal of a house due to theapplication of changes or enlargements.3.3.2 DEFINITION OF SUSTAINABLE RENOVATIONNow the definition of renovation is defined, the next question is: What is the definition ofa sustainable renovation?According to Juan, Goa & Wang (2009), sustainable renovation means implementingspecific actions which improve or upgrade building quality with regards to sustainabilityand ensuring that these actions are cost-effective and within the owner‟s budget.34

To come to a definition of the concept sustainable renovation, the cornerstones of theconcepts sustainable building and renovation are combined. The following statement isadopted as the definition of sustainable renovation in this research:“Sustainable renovation is the process of house adaptation with the goal to increasinglycomply with sustainability on environmental-, economic-, and social aspects.”3.3.3 ADVANTAGES OF RENOVATIONThe “Kenniscentrum Stedelijke Verniewing” states that there are advantages ofrenovation compared to demolition and new development on eight aspects. Thisparagraph gives an overview of all the advantages of renovation compared to demolitionand new development (Kenniscentrum Stedelijke Vernieuwing, 2010).ENVIRONMENT- Renovation causes less damage to the environment than demolition and newdevelopment. The aspects on which renovation scores better are: waste, requiredresources, emission of gasses, and energy use.FINANCES- In the research „Renovatiemogelijkheden portiekblokken Westelijke TuinstedenAmsterdam‟, Andeweg & de Jonge (2005) point out that renovation can be cheaperthan demolition and new development.- The degree of renovation is variable. Therefore, a larger scale of qualitydifferentiation is possible at renovation projects.- The relation between price and dimensions of a house is more positive at renovationprojects.- At renovation projects, the underground infrastructure stays intact. This decreasesrisks on this field, which mainly leads towards decreased costs.CONSTRUCTION- On average, the constructive condition of social rental houses in the Netherlands isgood. This increases the renovation possibilities and thereby the transformationpossibilities. (Kenniscentrum Stedelijke Vernieuwing, 2010).- Due to the variable degree of renovation, most houses are eligible for renovation.EXECUTION- Renovation has a shorter preparation period, due to less and shorter procedures.- At renovation projects it is possible to shorten the construction period, whichdecreases the costs.- A complex can be renovated in different phasesQUALITY OF LIVING- The quality of high level renovation resembles the quality of new development.- The quality of living increases, because the environment of living is familiar atrenovation projects.MARKET- In a tight housing market the focus will be more on possibilities for transforming thecurrent stock. Also in areas with a low offer of houses, renovation can be the answerfor the accommodation of people.LIVING ENVIRONMENT- The architectural coherence of buildings in an area can get lost due to demolition.- Renovation can contribute to the stratification of an area.35

SOCIAL EFFECTS AND OCCUPANTS‟ INFLUENCE- By applying renovation, the current social coherence of an area stays intact.- In case of renovation, the influence of occupants can be higher.- By applying renovation in a clever way, the inconvenience for the occupants remainslimited.- Large scale demolition and new development can result in segregation of socialclasses, which can lead to a concentration of lower social classes. In renovationprojects this effect can be avoided.- Nature areas are protected against cultivation3.4 EXISTING SUSTAINABILITY ASSESSMENT TOOLSOne of the main goals of this research is to develop a performance evaluation model forsustainable renovation concepts. Therefore, factors of influence on the performance ofsustainable renovation concepts are explored in this paragraph. For the identification ofimportant factors, four sustainability assessment tools that are currently used in theNetherlands are analyzed. Appendix M provides an evaluation of the quality of the fouranalyzed tools.3.4.1 GPR GEBOUWGPR Gebouw is a sustainability assessment tool that has been developed by W/EAdviseurs. GPR Gebouw focuses on three main aspects: energy, building physics, andenvironmental quality. Currently, about 150 municipalities and 150 commercialcompanies use the „GPR Gebouw‟ tool. By executing the GPR Gebouw assessment, thefollowing factors are taken into account:- Energy• Energy performance• Reduction of energy demand- Environment• Water• Environmental concerns• Materials- Health• Sound• Air quality• Thermal comfort• Light and visual comfort- User quality• Accessibility• Functionality• Technical quality• Social safety- Future value• Future-oriented facilities• Flexibility• Experience value3.4.2 BREEAMBREEAM (Building Research Establishment Environmental Assessment Method) has beendeveloped by the Building Research Establishment, which is a British research institute.BREEAM makes use of a qualitative weighing. The end score of a building can be pass,good, very good, excellent or outstanding. Hereby, the lowest possible score „pass‟ isequal to the legal minimum which is defined in the „Bouwbesluit‟ in the Netherlands.36

Currently, there are 330 BREEAM experts in the Netherlands, and 5 Dutch buildings areBREEAM certified. BREEAM considers the following aspects: (DGBC, 2010)- Management- Health- Energy- Transport- Water- Materials- Waste- Landuse and ecology- PollutionAppendix E provides more detailed information about the factors that are taken intoconsideration by executing the BREEAM assessment of a building.3.4.3 EPWIn the Netherlands, the official index for sustainability of buildings is the „energyperformance coefficient‟ (EPC). For houses, this EPC is determined with the sustainabilityassessment tool EPW. The calculations that determine the sustainability of a building areestablished in NEN norms. The EPC only considers the energy use that directly resultsfrom the house. This means, that the EPC evaluates the energy use that is needed for:- Heating the interior climate of a house- Cooling the interior climate of a house- Producing warm tap water- Lightning- Ventilation3.4.4 GREENCALCGreencalc has been developed by Sureac and evaluates sustainability on three themes:material use, water use, and energy use (www.greencalc.com). These themes aretranslated into one score, the environmental impact. A distinctive aspect of Greencalc isthat an integral life cycle analysis is the basis for the calculations. This makes it possibleto weigh and compare constructive and installation technical measures with each other.Greencalc takes four modules into consideration:- MaterialFor the determination of the environmental impact of a building, Greencalc uses lifecycle assessment (LCA) studies. An LCA gives insight in the environmental impactfrom cradle-to-grave. Next to quantitative information, also qualitative aspects ashealth, nuisance, and corrosion are taken into account.- EnergyThe energy module is based upon the norms that are used for the determination ofthe EPC, which is described in paragraph 3.4.3. These calculations are filled up byGreencalc, with the energy use that is not building bounded.- WaterThe water use is based upon the WPN (Water Prestatie Norm).- MobilityThe module mobility comes into consideration when districts are assessed. For asingle building this module is outside the scope of the calculations.37

Appendix F provides more detailed information about the factors that are taken intoconsideration by executing the Greencalc assessment of a building.3.5 LIFE CYCLE ASSESSMENTThree of the four evaluated models in the previous paragraph take environmental impactinto account. However, only Greencalc uses a life cycle assessment to determine the totalenvironmental impact of a building. For a sustainable renovation concept, the life cycleenvironmental impact is the best indicator, because the life cycle approach integrates allfactors with an impact on the environment. The life cycle approach provides a comprisingand comparable score for the environmental impact. Therefore, this paragraph shows aliterature review of the life cycle assessment (LCA) principal. Several definitions of lifecycle assessment are described. The interpretation of a life cycle assessment in thisresearch is based on the different definitions that are elaborated below. Also, theadvantages and disadvantages of a life cycle assessment are described. Informationabout the history and origination of the LCA principle is presented in appendix G.DEFINITIONS OF LCASAICIn the report „Life Cycle Assessment: Principles and Practice‟, SAIC (ScientificApplications International Corporation) provides information about a LCA withoutproviding a clear definition (SAIC, 2006).According to SAIC, life cycle assessment is a „cradle to grave‟ approach for assessingindustrial systems. Cradle to grave begins with the gathering of raw materials from theearth to create the product and ends at the point when all materials are returned to theearth. The characteristics of a LCA as stated by SAIC are listed below:- Evaluates all stages of a product‟s life.- Enables the cumulative environmental impactsin these stages.- Provides a comprehensive view of theenvironmental aspects of a product, processor service.- Can help decision-makers for making acomparison between alternatives on the fieldof environmental impact.FIGURE 19-LIFE CYCLE STAGES (SOURCE: EPA)Figure 19 illustrates the possible life cycle stages that can be considered in a LCA and thetypical inputs/outputs measured.SAIC states that the LCA process is a systematic, phased approach and consists of fourcomponents: goal definition and scoping, inventory analysis, impact assessment, andinterpretationFINKBEINERFinkbeiner et al. (2006) describe the new international standards for Life CycleAssessment in ISO 14040 & ISO 14044. According to these standards the followingprinciples are characteristics for a life cycle assessment.- LCA considers the entire life cycle of a product. The phases of the entire life cycle are:raw material extraction, energy and material production, manufacturing, use, end oflife treatment, and final disposal.- LCA addresses the environmental aspects and impacts of a product system. Aspectson the field of economic and social aspects are outside the scope of an LCA.38

- LCA is a relative approach, structured around a functional unit.- LCA is an iterative technique. The individual phases of an LCA influence each other.- LCA considers all attributes or aspects of natural environment, human health andresources. Therefore, potential tradeoffs can be identified and assessed.OWENSThe following definition of LCA is stated by Owens (1997):“LCA is an analytical methodology used to provide information on a product‟s energy,materials, wastes, and emissions from a life-cycle perspective along with an examinationof associated environmental issues.”According to Owens (1997), a life cycle assessment is:- A technique for systematically analyzing a product from cradle-to-grave- A mixed or hybrid analytical system- Output is usually given as quantitative mass loadingsThe stages of an LCA include:- Extraction of raw materials- Provision of energy for the operations and transportation between them- Material processing and fabrication- Product manufacture and distribution- Use- Recycling- Disposal of the wastes and the product itselfLCA consist of four components: (SETAC 1991; SETAC 1993a; Hunt et al. 1992; U.S. EPA1993; Lindfors et al. 1995)- Goal and scope- Inventory- Impact assessment- Improvement assessmentOwens states that the core of LCA consists ofcradle-to-grave life-cycle inventory analysisthat is fundamentally an engineering exercisedescribing a chemical, material, and energyaccounting balance for the entire productsystem. Figure 20 depicts a diagram of the lifecycle inventory (Owens, 1997).FIGURE 20-CONCEPTUAL DIAGRAM OF LIFE CYCLEINVENTORYHENDRICKSON, HORVATH, JOSHI & LAVEIn their article „Economic Input-Output Models for Environmental Life-Cycle Assessment‟Hendrickson, Horvath, Joshi & Lave (1998) state that:“A lifecycle assessment is an important tool used in pollution prevention and greendesign efforts.”Hendrickson et al (1998) state that LCA models have been developed to be able to makea careful examination of energy resource consumption as well as environmentaldischarges associated with each prevention or design alternative.SCHEUER & KEOLEIANScheuer & Keoleian (2002) describe LCA in their report as follows:“Life-Cycle Assessment is a comprehensive methodology whereby all the material andenergy flows of a system are quantified and evaluated”Hereby, they refer to researches and statements of: (Suzuki & Ota, 1998), (Adalberth,1997) & (Reijnders & van Roekel, 1999).39

Scheuer & Keoleian (2002) distinguish three flows of a product system that areinventoried by a LCA:- Upstream flows (extraction, production, transportation, construction)- Use flows- Downstream flows (deconstruction, disposal)Subsequently, global and regional impacts arecalculated based on energy consumption,waste generation and a select series of otherimpact categories. LCA makes it possible toweigh the impact of different systems andmaterials against each other. LCA promotesclarity of information and allows for greatercomparability of products. Figure 21 describesthe general format for a LCA, according to ISO14040 conventions (Reijnders & van Roekel,1999)FIGURE 21-ISO 14040 FORMATSAOUTERSaouter (2008) states the following definition for a life cycle assessment:“Life Cycle Assessment is a method developed to evaluate the mass balance of inputsand outputs of systems and to organize and convert those inputs and outputs intoenvironmental themes or categories relative to resource use, human health andecological areas.”In his article about life cycle assessment, Saouter states that life cycle assessment is atool used to evaluate the potential environmental impact of a product, process or activitythroughout its entire life cycle by quantifying the use of resources („inputs‟ such asenergy, raw materials, water) and environmental emissions („output‟ to air, water andsoil) associated with the system that is being evaluated.According to Saouter, a life cycle assessment is used to answer specific questions suchas:- How do two different manufacturing processes for the same product compare interms of resource use and emissions?- What is the benefit of changing technology?- What are the relative contributions of the different stages in the life cycle of thisproduct to total emissions?- What is the environmental footprint of my product, service, and company?In other words, life cycle assessment seeks to increase eco-efficiency. LCA takes intoaccount every phase in the life cycle of a product. Therefore, apparent improvementsthat only shift the problem around are recognized and can be avoided.AZAPAGIC & CLIFTAzapagic & Clift (1999) define LCA as follows:“LCA is a quantitative environmental performance tool essentially based around massand energy balances but applied to a complete economic system rather than a singleprocess.”According to Azapagic & Clift (1999) LCA can have two main objectives when applied toprocess analyses.1. Quantify and evaluate the environmental performance of a process from „cradle-tograve‟and thereby help decision-makers to choose between alternatives.2. Helping identify options for improving the environmental performance of a system.40

considers whole life cycleenvironmenthuman healthresourcesused energyused materialsemmisionswasteprovide informationcompare alternativeshelp decision makersrealize pollution preventionrealize green design effortshelp identify improvementsseek eco-efficiencygoal & scope definitioninventory analysisimpact analysisinterpretationimprovement assessmentDISCUSSIONThe interpretations that are elaborated in this paragraph differ from each other onseveral points, but it is also clear that the interpretations have points in common. Figure22 provides an overview of the characteristics that are assigned to LCA in this paragraph.Providesinformation onaspectsThe use of an LCA isConsists ofthe phasesSAIC X X X X X X X X XFinkbeiner et al X X X X XOwens X X X X X X X X X X X XHendrickson et al X X X X XScheuer & Keoleian X X X X X X X X XSaouter X X X X X XAzapagic & Clift X X XFIGURE 22 - OVERVIEW CHARACTERISTICS OF AN LCATo come to the interpretation of LCA that is used in this research, the differentmentioned characteristics are evaluated. Hereby, it is evaluated into what extend thementioned factors are; comprehensive, have a high occurrence at the analyzed articles,and fit the scope of this research. The interpretation of LCA that is used in this researchis presented in the bullets below.A life cycle assessment:- evaluates all stages of a product system‟s life.- provides a comprehensive view of the following aspects of a product:• natural environment• human health• resources- provides information that helps decision-makers or researchers to make a comparisonbetween different alternatives- consists of four phases• goal & scope definition• inventory analysis• impact analysis• interpretation41

BENEFITS AND LIMITATIONS OF LCABENEFITSThis section describes the benefits of a LCA.A LCA can help decision-makers select the product or process which results in the leastenvironmental impact. With other factors, such as cost and performance data, thisinformation can be used to select a product or process. LCA data identifies the transfer ofenvironmental impacts from one media to another (SAIC, 2006).Besides that, SAIC (2006) states that the ability to track and document shifts inenvironmental impacts can help decision makers characterize the environmental tradeoffsassociated with product or process alternatives.By performing an LCA, analysts can (SAIC, 2006):- develop a systematic evaluation of the environmental consequences associated with agiven product.- analyze the environmental trade-offs associated with one or more specificproducts/processes to help gain stakeholder (state, community, etc.) acceptance fora planned action.- quantify environmental releases to air, water, and land in relation to each life cyclestage and/or major contributing process.- assist in identifying significant shifts in environmental impacts between life cyclestages and environmental media.- assess the human and ecological effects of material consumption and environmentalreleases to the local community, region, and world.- compare the health and ecological impacts between two or more rivalproducts/processes or identify the impacts of a specific product or process.- identify impacts to one or more specific environmental areas of concern.LIMITATIONSNext to the benefits, SAIC (2006) also describe the limitations of a LCA. The limitationsof LCA are presented in the bullets below.- Performing a LCA can be resource and time intensive. This depends upon howthorough the user wants to execute the LCA and on the availability of the requireddata. Therefore, it is important to weigh the availability of data and the time that isneeded to conduct the study.- LCA does not say anything about the economic attractiveness of alternatives. Additivestudies should be conducted to gain information about the economics of alternatives.- There are a number of ways to conduct life cycle impact assessment. While themethods are typically scientifically-based, the complexity of environmental systemshas led to the development of alternative impact models.- To convert the impact results into a single score requires the use of value judgments,which must be applied by the executer of the study.3.6 LIFE CYCLE COSTINGThe private sector decision making contexts addressed by a life cycle assessment, mustalso take the economic consequences of alternative products into account (Norris, 2001).Norris (2001) also describes that the current LCA methodologies and tools do not addressinternal or external economic aspects in the decision making.According to Norris, the exclusion of life cycle costs into life cycle assessment has thefollowing consequences:42

- The influence and relevance of the LCA for decision making is limited- There is an inability to capture relationships among environmental and costconsequences. This also inhibits the search for the most cost-effective means toenvironmental improvements.- There is a potential to miss economically important or in some cases eveneconomically pivotal environment-related consequences to the company of alternativedecisions.In the report “Eco-efficiency – Combining Life Cycle Assessment and Life Cycle Costs viaNormalization”, Kicherer et al. (2007) introduce the concept of eco-efficiency. Thisconcept is a powerful decision support tool for various strategic and marketing issues.Also, eco-efficiency is one of the key goals in corporate environmental management. Ecoefficiencycomprises two dimensions:- Costs or added value- Environmental impactIt appears that the costs and environmental impact are important aspects that influencethe life cycle performance of products. In this paragraph more information about theconcept of life cycle costs is provided.DEFINITIONS AND ELEMENTS OF LCCIn the article “Life cycle costing-theory, information acquisition and application”,Woodward (1997) states that life cycle costing is concerned with optimizing value formoney in the ownership of physical assets, by taking into consideration all the costfactors relating to the asset during its operating life. According to Woodward (1997), oneof the most useful and short definitions of „life cycle costs‟ is:“The „life cycle costs‟ of an item is the sum of all funds expended in support of the itemfrom its conception and fabrication through its operation to the end of its useful life.”Woodward describes that life cycle costing helps to optimize the cost of acquiring, owningand operating physical assets over their useful lives.The objectives of life cycle costing are identified by Flanagan and Norman (1982). Theseobjectives are:- enable investment options to be more effectively evaluated- consider the impact of all costs rather than only initial capital costs- assist in the effective management of completed buildings and projects- facilitate choice between competing alternativesFlanagan and Norman (1983) define the following elements of life cycle costing:- Initial capital costs- Life of the asset- Discount rate- Operating and maintenance costs- Disposal cost- Information and feedback- Uncertainty and sensitivity analysisThe Building Services Research and Information Association (BSRIA) define life cyclecosting as “a method of project economic evaluation in which all costs arising, andbenefits accrued from installing, owning, operating, maintaining, and ultimately disposingof a project are considered to be potentially important to that decision.”(www.bsria.co.uk). According to the BSRIA there is only one evaluation criterion: thelowest life cycle costs.43

LCC tools are used to determine the total costs of an object over its total lifetime(Ravemark, 2003). Is his report „State of the art study of LCA and LCC tools‟, Ravemarkdescribes LCC to be particularly suited to the evaluation of design alternatives thatsatisfy a required performance level, but that may have different investments, operating,maintenance, or repair costs; and possibly different life spans. Ravemark also states thatan LCC calculation is particularly relevant when high initial costs are traded for reducedfuture cost obligations. According to Ravemark, a life cycle cost analysis is an economicanalysis technique that allows comparisons on investment alternatives having differentcost streams.In this report Ravemark (2003) also describes that due to the fact that the life cyclecosts of an object are very problem dependent, there are no general LCC tools that existand are applicable to various objects or problems.3.7 CONCLUSION - CONCEPT MODELAs stated before, paragraphs 3.4, 3.5, and 3.6 provide information that results in theidentification of factors of influence on the performance of sustainable renovationconcepts. Figure 23 shows the research components that are described in the previousthree paragraphs. The elaborated components are elements 1 and 2 in figure 23.1. Literature study2. Evaluation existing tools3. Interviews4. Model testingModeldevelopmentFIGURE 23 - RESEARCH COMPONENTS ELABOR ATED IN PARAGRAPHS 3.4, 3.5 & 3.6ModelapplicationBased on the elaborated research components in this chapter, a first concept of theperformance evaluation model is developed. Figure 24 provides a schematic overview ofthis concept model. Chapter 4 presents the identified factors of research components 3 &4 (see figure 25, page 45).Life CyclePerformanceLife CycleCostsLife CycleEnvironmentalImpactQualityEnergyPerformanceCoefficientMainfactorsExternal factorsFinancial factorsAssemblyLife cycleHealthUser quality1 st levelsubfactorsDisposalFuture valueDevelopmentenergy priceDiscount rateMaterialsProcessing &manufacturingTransport2 nd levelsubfactorsInitial investmentEnergy useOperating costsMaintenance costsReplacement ofelementsDisposal costsFIGURE 24 – CONCEPT MODEL BASED ON RESEARCH COMPONENTS 1 & 244

4. MODELThis chapter goes into detail on the model that is developed in this research. Paragraph4.1 provides the identified factors of influence of the executed research components.Paragraph 4.2 provides a more detailed description of the identified factors of influence inthe model and explains the model in more detail.Figure 24 shows a concept of the performance evaluation model for sustainablerenovation concepts. The identified factors of influence in this concept model areidentified on the basis of a literature study and an evaluation of existing sustainabilityassessment tools (research components 1 & 2). For this research, also expert interviewsand a model test have been executed (research components 3 & 4) to identify factors ofinfluence on the performance of sustainable renovation concepts (see figure 25).1. Literature study2. Evaluation existing tools3. Interviews4. Model testingModeldevelopmentFIGURE 25 - RESEARCH COMPONENTS ELABORATED IN PARAGR APH 4.1Modelapplication45

4.1 MODEL DEVELOPMENTFigure 26 provides the developed model after the execution of all four researchcomponents. Figure 26 also provides information about the source of the identifiedfactors of influence. The legend that is added to the figure shows in which researchcomponent the factor has been identified. The legend provides four colors that refer tothe four research components for model development. In figure 26, these four colors areappointed to the indentified factors of the model to explain the source of the identifiedfactors of the model.Boundary conditionsScopeReference buildingLifespan of buildingLifespan of elementsReplacementcosts of elementsChange over costsDisposal costsMaintenance costsOperating costsInitial investmentDevelopmentenergy priceDiscount rateThermal capacityInfiltrationFinancialfactorsExternalfactorsTransmissionTechnicalperformanceLCCRiskRentInstallationtechniquesEPCLCYPrimaryreturnsVentilationTap waterSpace coolingSpace heatingPerformanceSecundaryreturnsExit yieldUser healthQLCEIDisposalSoundAir qualityLife cycleThermal comfortLight & visualcomfortUser qualityAssemblyReplacementsTechnical qualityFuturevalueEnergyLEGENDLITERATURE STUDYEXISTING TOOLSEXPERT INTERVIEWSMODEL TESTINGFuture orientedfacilitiesFlexibilityExperienced valueMaterialsProcessing &manufacturingTransportFIGURE 26 - RESEARCH COMPONENTS & MODEL DEVELOPMENT46

4.2 MODEL & EXPLANATIONThis chapter provides an overview and detailed information about the developed modeland its integrated factors. The explanation of the model is provided on the basis of fourquestions. The questions that are answered in this chapter are listed in figure 27.Paragraph Question Explanation4.2.1 - Overview of the developed model4.2.2 What What is the model and what is measured by the model?4.2.3 Why Why is the model developed, and why are theseintegrated factors taken into account?4.2.4 Who and when Who benefits from the model and when is the modeluseful?4.2.5 How How should the output of the model be interpreted?4.2.6 - Detailed explanation of integrated factorsFIGURE 27 – ASPECTS OF MODEL DESCRIPTION4.2.1 MODELFigure 28 shows the “life cycle performance evaluation model” for sustainable renovationconcepts.Boundary conditionsScopeReference buildingLifespan of buildingLifespan of elementsReplacementcosts of elementsChange over costsDisposal costsMaintenance costsOperating costsInitial investmentDevelopmentenergy priceDiscount rateThermal capacityInfiltrationTransmissionFinancialfactorsExternalfactorsTechnicalperformanceLCCRiskRentInstallationtechniquesEPCLCYPrimaryreturnsVentilationTap waterSpace coolingSpace heatingPerformanceSecundaryreturnsExit yieldUser healthQLCEIDisposalSoundAir qualityLife cycleThermal comfortLight & visualcomfortUser qualityAssemblyReplacementsTechnical qualityFuturevalueEnergyFuture orientedfacilitiesFlexibilityExperienced valueMaterialsProcessing &manufacturingTransportFIGURE 28 - THE DEVELOPED LIFE CYCLE PERFORMANCE EVALUATION MODEL47

4.2.2 WHATThe model that is presented in figure 28 can be used to determine the performance ofsustainable renovation concepts on the basis of a life cycle approach. The life cycleapproach refers to a cradle-to-cradle consideration of the performance on the definedsustainability aspects for renovation concepts. Hereby, the cradle-to-cradle approachrefers to the potential advantages of reuse and up-cycling of materials and components.Therefore, the model is defined as a “life cycle performance evaluation model” forsustainable renovation concepts.The “life cycle performance” is composed by a renovation concept‟s life cycle:- performance on environmental aspects- performance on economic aspects, which consists of:• performance on life cycle costs• performance on life cycle yields- performance on quality aspects- energy performanceApplication of the model results in a comparison of the life cycle performance ofrenovation alternatives for a specific project. The model draws a distinction betweenprojects, because every renovation project is unique. As a result, the performance of arenovation concept, and thereby its feasibility and desirability can differ per project.The life cycle performance evaluation model integrates five main performance aspectsand boundary conditions. Figure 29 presents these five main aspects and the boundaryconditions. Appendix L shows a complete breakdown structure of the model and itsunderlying factors.BoundaryconditionsBoundaryfactorsLife CyclePerformanceLife CycleCostsLife CycleYieldsLife CycleEnvironmentalImpactQualityEnergyPerformanceCoefficientMainfactorsFIGURE 29 - MODEL ASPECTS4.2.3 WHYThis paragraph explains the „why‟ questions that are stated in figure 27. First, an answeris provided on the question: “Why is the model developed?”First, the evaluation of existing sustainability assessment tools in the Netherlands(appendix M) points out that the current existing models are mainly useful to determinethe sustainability of new development projects. As a result, these models are not- or lessuseful for the evaluation of sustainable renovation concepts.Secondly, the existing tools are incomplete. The existing models only focus on one or afew aspects that are relevant for the performance of sustainable renovation concepts.Thus, none of the current models provides a comprising view on the performance of asustainable renovation concept.48

Lastly, the existing models lack a whole life cycle approach. The models provide aperformance that represents the performance of a renovation concept on the moment ofevaluation, instead of taking into account the whole life cycle of a building.The developed life cycle model integrates five main factors that influence the life cycleperformance of a renovation concept. This section explains why these factors areintegrated in the model and how these factors are identified.ENERGY PERFORMANCE COEFFICIENTThe first factor that is identified is the energy performance coefficient (EPC). The energyperformance coefficient is an index that is used in the Netherlands to indicate the energyefficiency of buildings.The EPC is integrated in the model because:- EPC is an important communication aspect of sustainability.Technical information about sustainability is complicated to understand. The EPCresults in an energy label, which is a sustainability score that is expressed in a simpleway and therefore understandable for a large public. This makes the EPC animportant communication tool of sustainability for the large public.- Laws and regulations from the Dutch government rest on the EPC of a building.The EPC of a building plays an important role in laws and regulations that areprovided by the Dutch government. The Dutch “Bouwbesluit” for example, definesminimal requirements for the EPC of newly developed or thoroughly renovatedhouses. Also, the new “woning waarderingstelsel (WWS)” integrates the EPC in theregulation. The WWS prescribes the rent level that a housing corporation can chargefor their houses. This rent level is influenced by the EPC of a house.Therefore, the EPC is an important factor of influence at determining the life cycleperformance of a renovation concept.The EPC is identified as a factor of influence as a result of the evaluation of the existingsustainability assessment tools- EPW- GPR Gebouw- GreencalcNext to that, the EPC is mentioned as a factor of influence on the performance ofrenovation concepts three of the executed expert interviews. The experts that mentionedthe EPC as a factor of influence are listed in appendix B. Also, the executed literaturestudy resulted in the identification of the EPC as an important factor of influence on thesustainable performance of products. Lastly, the sub-factors that compose the EPC areidentified on the basis of the model testing phase.LIFE CYCLE ENVIRONMENTAL IMPACTThe life cycle environmental impact (LCEI) represents the impact of a renovation concepton all the current identified environmental categories, over the whole life cycle of abuilding.The LCEI is integrated in the model because:- It provides the most comprising view on the environmental impact of a renovationconcept.Most of the current sustainability assessment tools only evaluate the environmentalimpact on the aspect of CO 2 emissions. Although this may be the most actualcategory of impact at this moment, there are several other impact categories thatcannot be neglected. It is plausible that the importance of impact categories change49

in time, due to changed insights. The environmental impact categories that are takeninto account by a LCEI evaluation are:• Greenhouse gasses• Ozone layer• Acidification• Eutrophication• Heavy metals• Carcinogens• Pesticides• Summer smog• Winter smog• Energy resources• Solid wasteAt the evaluation of the LCEI, a weight factor has to be assigned to each impactcategory, which makes it possible to connect with the actual interpretation on impactcategories at all times.The LCEI is identified as a factor of influence as a result of the evaluation of the existingsustainability assessment tools- GPR Gebouw- GreencalcBesides that, the LCEI is mentioned as a factor of influence on the performance ofrenovation concepts at two expert interviews. The experts that mentioned the LCEI as afactor of influence are listed in appendix B. Also, the executed literature study points outthat the execution of a life cycle assessment of a product provides the most comprisingview on the environmental impact of the product, and therefore is an important factor ofinfluence on the performance of sustainable renovation concepts. Lastly, the sub-factorsthat determine the LCEI are confirmed in the model testing phase.LIFE CYCLE COSTSThe life cycle costs (LCC) are costs that result from the application of a renovationconcept, the energy and maintenance costs during the life cycle of a building, and thedisposal costs at the end of life of a building.The LCC factor is integrated in the model because:- Large scale housing renovation is only realized if it is financial feasible.Companies as real estate developers, real estate investors, and housing corporationsmainly focus on the financial feasibility of projects. These parties have the capacityand competences to execute large scale housing renovations. However, they will onlyexecute a renovation project if they are convinced about the attractiveness on thefinancial aspect. In other words, the sustainability aspect is inferior to the financialaspect in most cases. This situation also accounts for individual house owners.As a result of the motivation above, the financial aspect has to be integrated in themodel. None of the current existing tools integrates the financial aspects in thesustainable performance evaluation.The LCC is mentioned as a factor of influence on the performance of renovation conceptsat five expert interviews. The experts that mentioned the LCC as a factor of influence arelisted in appendix B.Besides that, the executed literature study resulted in the identification of the LCC as animportant factor of influence on the sustainable performance of products. In severalscientific articles, the principle of eco-efficiency is introduced. This principle refers to theintegration of financial aspects to the life cycle assessment of products. The exclusion of50

the financial aspect can lead to various negative consequences, see paragraph 3.6, page42. Also, the sub-factors that compose the LCC are identified and evaluated on the basisof the model testing phase.LIFE CYCLE YIELDSThe life cycle yields (LCY) are the expected yields that result from the collected rent, thesale value, and the risks that play a role at the renovated house.The LCY factor is integrated in the model because:- It influences the financial feasibility of a concept.Companies that are able to execute large scale renovation projects at houses such ashousing corporations and real estate investors determine the financial feasibility of aproject on the basis of the life cycle costs and the life cycle yields of a project. Thetotal profit of a project is the result of the yields minus the costs.Thus, the integration of the life cycle yields in the model completes the financialfeasibility of a renovation concept. Therefore, this factor is integrated in the developedmodel.The LCY is mentioned as a factor of influence on the performance of renovation conceptsat five expert interviews. The experts that mentioned the LCY as a factor of influence arelisted in appendix B.QUALITYThe quality of a renovation concept refers to the level of appreciation that can beascribed to a house. The level of appreciation is composed by the user health, userquality, and future value of a house, based on the quality characteristics of the house.The quality factor is integrated in the model because:- It influences the desirability and thereby the feasibility of a renovation concept.If a renovation concept is sustainable from environmental point of view, but is alsocharacterized by a low quality, the renovation concept is undesirable. A low level ofcomfort on the aspects air, sound, temperature or light makes a houseuncomfortable. This increases the chance on dissatisfaction at the occupants of ahouse, which results in an increased chance on vacancy.- It influences the financial feasibilityA better performance on quality can result in higher life cycle yields and a longerexploitation period of a house. A longer exploitation period results in a higher level ofsustainability of a house.Based on the explanation above, the quality is integrated as a factor of influence on thelife cycle performance of renovation concepts.The quality is identified as a factor of influence as a result of the evaluation of theexisting sustainability assessment tools- GPR Gebouw- BREEAMThe quality of a renovation concept is mentioned as a factor of influence on theperformance of renovation concepts at five expert interviews. The experts thatmentioned the quality of a renovation concept as a factor of influence are listed inappendix B. Also, the executed literature study resulted in the identification of the factor„quality‟ as an important factor of influence on the performance sustainable renovationconcepts. The sub-factors that compose the quality of a concept are identified andevaluated on the basis of the model testing phase.51

BOUNDARY CONDITIONSTo create a comprising view of the sustainable performance of renovation concepts, a lifecycle approach is required. To be able to determine the life cycle impact, informationabout the current situation of a project and the life cycle behavior of a renovationconcept must be analyzed. Therefore, the boundary conditions are integrated in themodel.The boundary conditions are identified as a factor of influence, mainly as a result of themodel testing phase of this research.4.2.4 WHO AND WHENThe “life cycle performance evaluation model” provides insight in the performance ofrenovation concepts. The model is beneficial for three parties:1. Companies that have an economical interest in real estate2. Individual house owners3. The sector that develops sustainable renovation conceptsThe model is beneficial for parties with an economical interest in real estate, such as realestate (renovation) developers, real estate investors, housing corporations and individualhouse owners without specialist knowledge of sustainable renovation. These parties canuse the model to determine the most desired and attractive renovation concept for aselected piece of real estate based on their interests and requirements. The model isuseful, when the choice for the execution of a sustainable renovation is made but there isuncertainty about the most desired renovation concept. The model also can be used todetermine whether it is effective and sustainable at all to implement sustainablerenovation measures, by selecting the renovation alternative „no renovation‟ at theevaluation of alternatives. Besides that, this model can be used by companies thatdevelop innovative sustainable renovation concepts or applications. These companies canuse this model to illustrate the performance and specific advantages of their newlydeveloped concept or application compared to competitive concepts or the currentsituation.4.2.5 HOWThis paragraph describes the way the model output should be interpreted. Application of1the model results in a diagram as presented in figureLCC30. To optimize the comparability of this output, thediagram shows the normalized score of the evaluatedalternatives. Hereby, the best score on each aspect isrepresented by the score 1. The scores of the otherLCY11alternatives represent the normalized score. Hereby EPCthe alternative with the score 1 forms the norm andthe score of other alternatives lies between 0 and 1.Example:In this research, three renovation alternatives areevaluated on the factor EPC. The results are:WarmBouwen: EPC = 0.7Standard renovation: EPC = 1.23No renovation: EPC = 2.22The EPC of WarmBouwen is the best and therefore scores 1.1QScenario x.2.2.2- lifespan building: +50 years- lifespan elements/change rate: expected- Increase energy price: +8%No renovation1Standard renovationLCEIWarmBouwen renovationFIGURE 30 - MODEL OUTPUT DIAGRAM52

The normalized score of the „standard renovation‟ alternative =The normalized score of the „no renovation‟ alternative =When the scores on each factor of influence are determined, the total life cycleperformance can be determined. The total life cycle performance is presented by thefive-axis radar chart, as presented in figure 30. However, the performance dependsstrongly on the interests and requirements of the owner. An individual house owner witha high appreciation of sustainability and environmental protection and a low appreciationof the financial aspect ascribes other weight factors to the importance of the five mainfactors of the model than a real estate investment company that mainly wants toincrease profit. Therefore, it is not possible to provide a one-sided answer on thedetermination of the best overall life cycle performance. Paragraph 6.3, page 81 providesa suggestion for the determination of the total life cycle performance of renovationconcepts.4.2.6 MODEL FACTORS EXPLANATIONFigure 31 shows the “life cycle performance evaluation model” for renovation concepts.This paragraph explains the integrated factors and sub factors in more detail.Boundary conditionsScopeReference buildingLifespan of buildingLifespan of elementsReplacementcosts of elementsChange over costsDisposal costsMaintenance costsOperating costsInitial investmentDevelopmentenergy priceDiscount rateThermal capacityInfiltrationTransmissionFinancialfactorsExternalfactorsTechnicalperformanceLCCRiskRentInstallationtechniquesEPCLCYPrimaryreturnsVentilationTap waterSpace coolingSpace heatingPerformanceSecundaryreturnsExit yieldUser healthQLCEIDisposalSoundAir qualityLife cycleThermal comfortLight & visualcomfortUser qualityAssemblyReplacementsTechnical qualityFuturevalueEnergyFuture orientedfacilitiesFlexibilityExperienced valueMaterialsProcessing &manufacturingTransportFIGURE 31 – THE LIFE CYCLE PERFORMANCE EVALUATION MODEL FOR SUSTAINABLE RENOVATION CONCEPTS53

BOUNDARY CONDITIONS- ScopeThe scope of the model provides general information about the characteristics of therenovation alternatives that are evaluated. Also the cadre of the assessment isdescribed.- Reference buildingThe reference building is the building (or complex) that is renovated. Constructiveand installation technical characteristics of the building are described.- Lifespan of buildingThis factor describes the expected exploitation period of the building after renovation.The expected lifespan of the building and the expected behavior during this lifespaninfluences the life cycle performance of sustainable renovation concepts.- Lifespan of elements (& change rate)The lifespan of elements is a factor that refers to the expected lifespan of allinstallations and constructive measures that are applied at the renovation. Besidesthat, this factor determines the expected rate of functional changes within the houseduring its lifetime.LIFE CYCLE COSTS (LCC)FINANCIAL FACTORS- Initial investmentThe initial investment is required to execute the sustainable renovation. Theinvestment is made at the start of the life cycle of the renovated building.- Operating costsThe operating costs are the costs for energy use during the life cycle of the building.Mostly these are costs for gas and electricity use.- Maintenance costsThe maintenance costs are the costs for maintaining the installations that areintegrated in a renovation concept. Boilers, heat pumps, aquifers, and ventilators arecomponents of a concept that have to be maintained during the lifetime.- Disposal costsDisposal costs are costs that result from disposing the renovation concept orelements of the renovation concept at the end of the life cycle.- Change over costsBefore a renovation concept can be applied to a dwelling, it is probable that the oldinstallation techniques and in some cases constructive elements have to be removedor adapted. The costs that are involved for the preparation of the new techniques andelements are the change over costs.- Replacement costs of elementsDuring the life cycle of a house, elements must be replaced due to several reasons.Expiration of the technical life cycle of an element can result in replacement of theelement. Also functional changes and internal alterations can lead to replacement ofelements. The costs that are involved in these replacements are called thereplacement costs of elements.EXTERNAL FACTORS- Discount rateThe discount rate is an interest rate that is charged or provided by financial instanceswhen you borrow or store money.- Development of energy pricesThe development of the energy prices is a factor that determines the development ofthe costs for energy use during the life cycle of a building. For a life cycle cost54

calculation, an assumption or expectation for the development of the energy price isrequired.LIFE CYCLE YIELDS (LCY)PRIMARY RETURNS- RentRent is the price that tenants pay for renting a house or accommodation.SECONDARY RETURNS- Exit yieldThe exit yield is the price that an owner receives when a house or accommodation issold at the end of the exploitation period.RISK- There is a chance that initial expectations and estimations differ from reality. Thefactor risk refers to this chance. Risks are characterized by a chance from occurringand the impact at occurrence.LIFE CYCLE ENVIRONMENTAL IMPACT (LCEI)ASSEMBLY- MaterialsThe type of materials that are used in a renovation concept and the amount of theused materials influence the environmental impact of a concept. The environmentalimpact that results from initial material use by the renovation concept are determinedby this factor.- Processing and manufacturingThe assembly process that is required to produce the elements within a renovationconcept causes energy use. The energy and materials that is used at the assemblyprocesses of renovation elements is determined by the factor processing andmanufacturing.- TransportThis factor refers to the environmental impact that is caused by the transportation ofmaterials and elements of a renovation concept. The environmental impact caused bytransport is determined from resource extraction to the delivery of elements on thebuilding site.LIFE CYCLE- EnergyThis factor refers to the environmental impact that is caused by energy use duringthe life cycle of a building. In most cases, the energy use is composed by gas use andelectricity use.- ReplacementsDuring the life cycle of a house, elements are changed due to several reasons.Expiration of the technical life cycle of an element can result in replacement of theelement. Also functional changes and internal alterations can lead to replacements ofelements. These replacements result in environmental impact, due to the materialsthat are used in the elements that are replaced and due to transport of the replacedelements.55

DISPOSALThe disposal factor determines the environmental impact that results from the disposal ofelements and materials that are applied during the life cycle of a building. Typicaldisposal scenarios are landfill, incineration, and recycling.QUALITY (Q)USER HEALTH- SoundThis factor refers to the the acoustic comfort in a house. The acoustic comfort isdetermined by the sound level within a house. A renovation concept potentiallyinfluences the acoustic comfort of a house- Air qualityThe amount of gasses, dust, and incoming fresh air at the interior climate of a houseinfluences the interior air quality. The interior air quality can be improved by applyingconstructive measures or installation techniques during a renovation.- Thermal comfortThe thermal comfort refers to the experienced interior comfort within a houseregarding temperature and air streams.- Light- and visual comfortThe light and visual comfort is mainly determined by the amount of daylight that isperceptible inside a house.USER QUALITY- Technical qualityThis factor provides information about the technical condition of the installations thatare used for interior climate control in a house. Based on this condition of theinstallation technical components, points are assigned to a renovation concept.FUTURE VALUE- Future oriented facilitiesThis factor refers to the application of high-grade materials and the compatibility of ahouse and its installations with future techniques, future adaptations, and futurefacilities.- FlexibilityThe flexibility refers to the adjustability, changeability, and possibilities for expansionof a house and its integrated installations.- Experienced valueThe experienced value is determined by the value that can be ascribed to theenvironment-, the outside-, and the inside of a house, by its occupants.ENERGY PERFORMANCE COEFFICIENT (EPC)TECHNICAL PERFORMANCE- Thermal capacityThe thermal capacity refers to the amount of heat or cold that can be stored in theconstruction of a building. If a building has a high thermal capacity, it reacts slowlyon temperature changes. This decreases extreme interior temperatures.- InfiltrationThe infiltration is the amount of air that infiltrates in the building. More infiltrationresults in a higher demand of energy for interior climate regulation.56

- TransmissionThe transmission of a house refers to the amount of temperature exchange betweenthe interior and the exterior of a building. A high degree of transmission results in ahigher energy demand for interior climate regulation.INSTALLATION TECHNIQUES- VentilationIn a house, several ventilation techniques can be applied to refresh the interior air.The type of ventilation that is applied in a house influences the energy demand forventilation and the energy demand for interior climate regulation.- Tap waterThis factor refers to the installation that is applied to fulfill in the demand for warmtap water. Warm tap water is used for activities like showering and cooking.- Space heatingThis factor specifies the characteristics of the installation that is used to fulfill in thedemand for space heating.- Space coolingThis factor specifies the characteristics of the installation that is used to fulfill in thedemand for space cooling.57

5. MODEL APPLICATIONThis chapter presents the results of the model application. The model application is thelast phase of this research before the conclusions are stated. Figure 32 provides anoverview of the relation between the four research components and the modelapplication.1. Literature study2. Evaluation existing tools3. Interviews4. Model testingFIGURE 32 - MODEL APPLICATIONModeldevelopmentModelapplicationThe factors of influence on the performance of sustainable renovation concepts areidentified and integrated in the model that is described in chapter 4. This chapterelaborates the application of the model on three cases. The application of the modelprovides information that is used to answer the research questions:4. What is the composition of- and correlation between the identified factors ofinfluence?6. What is the sustainable performance of WarmBouwen?7. What are improvements for the WarmBouwen renovation concept?The developed „life cycle performance evaluation model‟ contains three factors that arehard to predict or are determined based on the requirements and wishes of the owner.These factors are „lifespan of building‟, „lifespan of elements/change rate‟, and„development of energy prices‟. For this research it is impossible to define a one-sidedinput parameter on these factors. Therefore, three scenarios are defined for thesefactors. These defined scenarios result in performance information of each renovationalternative at the defined scenarios. Also, information about the capability of therenovation alternatives to deal with unforeseen changes in the boundary conditions canbe derived.This chapter regularly refers to a scenario, which is indicated by a scenario code. Toclarify the system between scenarios and their accompanying code, an explanation of thescenario system is given below.SCENARIO CODESEach scenario has a code: [A.B.C.D]A: Indicates the renovation conceptA=1: No renovationA=2: Standard renovationA=3: WarmBouwen renovationB: Indicates the extension of the lifespan of the building after renovationB=1: Extension of the lifespan is lower than expected (25 years)B=2: Extension of the lifespan is as expected(50 years)B=3: Extension of the lifespan is higher than expected (75 years)C: Indicates the functional lifespan of the elements in therenovation concept & the functional change rate during thelifespan of the buildingC=1: Functional lifespan of the elements is lower than expected &functional change rate is higher than expected58

C=2: Functional lifespan of the elements is as expected &functional change rate is as expectedC=3: Functional lifespan of the elements is higher than expected &functional change rate is lower than expectedLEGEND: SCENARIO [A.B.C.D.]A=1 RENOVATION ALTERNATIVE 1A=2 RENOVATION ALTERNATIVE 2A=3 RENOVATION ALTERNATIVE 3B=1 +25 YEARS EXPLOITATIOND: Indicates the development of the energy pricesD=1: Increase of energy price is lower than expected (5%)D=2: Increase of energy price is as expected (8%)D=3: Increase of energy price is higher than expected (11%)B=2B=3C=1C=2C=3D=1+50 YEARS EXPLOITATION+75 YEARS EXPLOITATIONLOW FUNCTIONAL LIFESPAN/HIGHCHANGE RATEEXPECTED FUNCTIONAL LIFESPAN/EXPECTED CHANGE RATEHIGH FUNCTIONAL LIFESPAN/LOWCHANGE RATE+5% ENERGY PRICESFigure 33 shows a legend which refers to these defined scenario codes.FIGURE 33 -Example: The characteristics of scenario [1.3.1.2] are:SCENARIOS CODES- The „no renovation‟ concept is applied- Extension of the lifespan of the building is 75 years after renovation- Lifespan of the elements is shorter than expected and the functional change rate ishigher than expected- The increase in energy prices is as expected.Appendices C.1 and C.2.1 provide the foundation of the determined scenarios for eachfactor.Appendix Q provides an overview of all the scenarios that are defined in this research,with accompanying characteristics.D=2+8% ENERGY PRICESD=3 +11% ENERGY PRICES5.1 CASE WARMBOUWENThe WarmBouwen concept is one of the three renovation alternatives that are evaluatedat the model application. This paragraph provides more information about theWarmBouwen concept to answer research question 5, which is stated below.5. What are the characteristics of WarmBouwen?The information that is used for this section has been gained by consulting 4 experts inthe field of WarmBouwen. Appendix B provides a list with the four consulted experts.CHARACTERISTICS OF WARMBOUWENWarmBouwen is an innovative sustainable renovation concept developed by „LocalCompany‟ and „KBNG Architects‟.PRINCIPLESWarmBouwen is a technique that is based upon the advantages of mass in a building,which provides a constant interior temperature. The principal of WarmBouwen rests onaccumulation instead of insulation. The basic thought is to bring a building into balancewith its environment; climatologic and energetic. WarmBouwen makes use of existingand proven techniques. The combination of these techniques is new. More informationabout the differences between accumulation and insulation is provided in appendix H.WarmBouwen distinguishes two important principals.Principle 1Mass is slow en provides a constant temperature to interiors. In the Dutch climate thisconstant temperature is approximately thirteen degrees Celsius.59

Principle 2:Water can be used to prevent transmission of temperature between the inside and theoutside of a building. The use of water makes it possible to harvest, transport and storethermal energy.THE CONCEPTThis paragraph describes theWarmBouwen concept step bystep. Figure 34 shows aschematic overview of theWarmBouwen concept. The fivebullets below provide additionalexplanation for the situation ofWarmBouwen in winter. Insummer this scheme is equal,only cold instead of heat istransported and emitted to thebuilding.FIGURE 34-WARMBOUWEN IN WINTER1. Warm water, from the warm zone in the aquifer, is transported from the soil towardsthe building at the surface. The transportation of the water takes place by a pump.2. If required, the temperature of the water is increased by a heat pump, once the waterfrom the aquifer arrives at the building.3. The warm water is transported through the building by piping that is processed inwalls, floors and/or ceilings.4. The piping, that is used to transport the warmwater through the building, emits its heat to thewalls, floors and/or ceilings in which the pipingis processed. The piping that is processed inwalls, floors or ceilings, is called an “aquiferouspackage” and emits the heat to the interior ofthe building. An image of the aquiferouspackage is depicted in figure 35.FIGURE 35- AQUIFEROUS PACKAGE5. The warm water emits its heat to walls, floors and/or ceilings. As a result, the watercools down. This cold water is transported to the cold zone of the aquifer, where thecold is stored. In summer this cold water is used to cool the building in the same waythe building is heat up in winter.WarmBouwen aims to prevent transmission of energy from the interior of a building bybalancing with the underlying aquifer. Due to the aquiferous package, accumulation takesplace, as described in the five steps above. More information about the principle ofaccumulation is provided in appendix H.60

The aquiferous package is essential for the WarmBouwen concept. Next to thetransportation of warm or cold water, it forms the connection between the buffer areaand the place where the heat or cold gets emitted to the interior of a building. Theamount of piping that is processed in a building depends on the required capacity.In history theaccumulationoftemperature took placein the enormous mass ofthe walls of buildings, as37described in appendix I.265In case of WarmBouwen,148accumulationofsummertemperature takes placein the aquifer. This bringsthe building into balancewith its underlyingaquifer. The advantage ofaquiferaquiferthe WarmBouwentechnique in comparisonto the massive walls(appendix I) is that themassive wall of 2-3meters thick is notneeded anymore. The same end result is reached with a thin wall with an aquiferouspackage processed in it. Thus, the aquiferous package replaces the functions of masswithout the disadvantage that it is heavy. Figure 36 shows the principal of WarmBouwenin a house in summer and in winter.USED TECHNIQUES1234COOLING THE BUILDINGGAINING HEATSUN DELIVERS 12W/M 2HUMANS DELIVER 4W/M 2To explain WarmBouwen in more detail, the used techniques of the concept areelaborated separately in this section. A distinction is made between storage, generation,distribution, and emitting.STORAGEFor the storage of heat and cold, an aquifer isused. An aquifer is a system with bubbles of stillstanding water, in which different temperaturezones can be applied, see figure 37. There is onlyminor interaction between the different zones. Thismakes it possible to apply different temperaturezones, because only minor heat exchange or heatlosses occur within the zones. An aquifer must beregulated. This regulation is done by storing heatand cold in the available temperature zones. Heatthat is gained in summer is transported and storedin the heat zone. In winter this heat is used to heatFIGURE 37-HOT AND COLD ZONEthe building. Cold that is gained in winter getstransported and stored in the cold zone. In summer this cold is used to cool the building.The temperature of the different temperature zones in the soil is not sufficient to supplythe total required heat or cold. Therefore, a heat pump is part of the system to providethe required rest heat and cold. More information about the heat pump is described inthe next section.An aquifer can be replaced by a closed loop system, figure 38. Most installed closed loopsystems consist of two loops: the primary refrigerant loop is contained in the appliancecabinet where it exchanges heat with a secondary water loop that is placed in the soil.The secondary loop contains a mixture of water and anti-freeze. After leaving the internal5674HEATING THE BUILDINGGAINING COLDFIGURE 36 - WARMBOUWEN IN SUMMER AND WINTERSUN DELIVERS 4W/M 2HUMANS DELIVER 12W/M 261

heat exchanger, the water flows through the secondary loop outside thebuilding to exchange heat with the ground before returning. Thesecondary loop is placed below the frost line where the temperature ismore stable or preferably submerged in a body of water if available.Closed loop systems need a heat exchanger between the refrigerant loopand the water loop, and pumps in both loops. Closed loop tubing can beinstalled horizontally, as a loop field in trenches or vertically, as a seriesof long U-shapes in wells. A vertical closed loop field is composed of pipesthat run vertically in the ground. Therefore, a hole is bored in the ground.This hole is between 23 and 152 meter deep. The depth of the holedepends on the required capacity.FIGURE 38-CLOSEDLOOP SYSTEMGENERATIONMost of the systems that make use of soil temperature are combined with a heat pump.A geothermal heat pump is a central heating and cooling system that pumps heat to andfrom the soil. It uses the earth as a heatsource in the winter or a heat sink in thesummer. The heat pump takes advantageof the moderate temperatures in theground to improve efficiency and therebyreduce the operating costs of heating andcooling systems.The core of the heat pump is a loop ofrefrigerant pumped through a vaporcompressionrefrigeration cycle thatmoves heat. Unlike an air-source heat FIGURE 39-HEAT PUMP SCHEMATICpump, that transfers heat to or from the outside air, a ground source heat pumpexchanges heat with the ground. This is more energy efficient because undergroundtemperatures are more stable than air temperatures through the year. Seasonalvariations drop off with depth and disappear below seven meters due to thermal inertia.Figure 39 shows a schematic overview of a heat pump.DISTRIBUTIONFor the distribution of water through the system of WarmBouwen, a pump is required.The pump takes care of the transportation of water through the aquiferous package. Thepiping itself has got two functions.- The first function is the transportation of water from the heat storage towards thecold storage (or the other way around).- The second function is to emit heat and cold to the interior of the building via thewalls, floors or ceilings.The piping that is processed in the walls transports water from A to B. The piping is alsoresponsible for a comfortable interior climate, the comfort temperature.EMITTINGWarmBouwen emits heatand cold via the skin ofthe building. Anaquiferous package isadded to the facades,floors and/or ceilings. Seefigure 40 and 41. It ispossible to add anaquiferous package to theinside as well as theoutside of a building. Thisdepends on theFIGURE 40-AQUIFEROUS PACKAGE FLOORFIGURE 41-AQUIFEROUS PACKAGEWALL62

possibilities that a building offers. There is a difference between adding WarmBouwen atthe inside or at the outside of the building. By applying WarmBouwen at the inside, lessenergy is exchanged but the system as heater or cooler for the user is faster. By applyingWarmBouwen at the outside, more energy is exchanged but the system is morebalanced. The system as heater or cooler is slower and this application demands antifrost measures to prevent the system from freezing.The aquiferous package, which is processed in the walls, floors, and/or ceilings, isconnected to the aquifer (see figure 36).The capacity of WarmBouwen depends on the density of the water net and the currentvelocity of the water.ADVANTAGES OF WARMBOUWENThis section describes the advantages of WarmBouwen compared to conventionaltechniques for interior climate control.COMFORT AND HEALTHWarmBouwen is a technique that makes use of natural ventilation and thereby provides aconstant flow of fresh air. It also prevents the recirculation of used air. New developedoffices and houses mostly make use of mechanical ventilation nowadays, whereby only alittle amount of fresh air enters the building.WarmBouwen emits heat and cold to the rooms in a building via radiation instead ofconvection. Radiation heat is more comfortable than convection heat. The radiation heatcontributes to the higher level of comfort of WarmBouwen.Due to WarmBouwen, there is no need to apply thick insulation and vapor proof foils toprevent condensation. This results in „breathing walls‟ which contribute to a healthyinterior. The arguments above provide a healthy and comfortable interior climate.ENERGY, ECONOMY AND BALANCEWarmBouwen makes use of the average environment temperature as standardtemperature. Less energy is required to heat and cool the building. Therefore, energycosts are decreasing and less CO 2 is produced at the interior climate regulation of abuilding.ARCHITECTURE AND BUILDINGDue to the principle of accumulation instead of insulation, the thickness of the walls of abuilding can be limited. This results in several advantages.- Less material is needed, which leads to decreasing costs and less material usage.- More space remains for the user of a building.- In case of renovation, the existing architecture can be preserved.LOW TEMPERATURE HEATINGAnother advantage of WarmBouwen is that it makes use of low temperature heating. Lowtemperature heating is a heating system whereby the supply heat of the system is below55° Celsius and the return heat of the system is 45° Celsius maximum. In a conventionalsystem the temperature of supply heat is about 90° Celsius, and the temperature of thereturn heat is about 70° Celsius.There are several advantages of a low temperature heating system over a conventionalheating system. In the brochure „Naar duurzaam comfort met lage temperatuurverwarming (LTV)‟ (SenterNovem, 2002) the advantages of low temperature heatingsystems are described. SenterNovem recognizes the following advantages:ENERGETIC ADVANTAGES- Low temperature heating systems are more efficient than conventional systems.Therefore, the returns are higher.63

- In case of a heat distribution network, the supply heat of the system is lower.Therefore, the temperature of the network is lower and less energy losses occurduring transport.- A low temperature heating system is more compatible with renewable energysources, such as solar energy and geothermal sources.USER ADVANTAGES- The indoor air quality is higher and the thermal comfort is higher, due to heat viaradiation instead of convection.- If properly applied, floor- and wall heating systems provide a better sound insulation.- Without radiators the user has more freedom in furnishing the spaces.- There is a lower risk of burning, due to lower temperatures.DISADVANTAGES OF WARMBOUWENThe bullets in this section describe disadvantages of the WarmBouwen concept.- The thickness of the aquiferous package that transports and emits heat and cold inthe house is approximately 3 centimeters. Applying this aquiferous package results ina decreased interior surface. Applying WarmBouwen on floors can result in heightdifferences in the house.- In the WarmBouwen concept, the walls are activated and used to heat and cool theinterior climate. Therefore, it is not possible to place large elements in front of thewalls that are activated as climate regulation wall, because the emitting of heat andcold to the building is hindered by large elements.- Due to the piping that is processed in the walls, it is impossible to apply nails orscrews in the walls without checking the presence of piping in the walls. Nails andscrews can cause leaks in the system. A water leak may cause damage at occurrence.- A heat pump is larger than a boiler. This can cause problems at placing the heatpump in a house.- It is impossible to apply the WarmBouwen concept to occupied houses. Therefore,only unoccupied houses are eligible for the WarmBouwen concept. If WarmBouwen isapplied to occupied houses, the occupants have to be replaced. This replacementprocess may lead to resistance of occupants. Also the replacement process bringsalong high replacement costs.5.2 BOUNDARY CONDITIONSInput parameters on the „boundary conditions‟ are required if the model is applied on acase. This subparagraph provides information about the determination of these inputparameters at this model application.SCOPEIn this assessment, 3 alternatives for the renovation of a house are evaluated andcompared. Appendix C1 provides detailed information about the renovation alternatives.The selected alternatives are:1. No renovation2. Standard renovation3. WarmBouwen renovationREFERENCE BUILDINGThe renovation is applied to a standard row house in the Netherlands, which is builtbetween 1945 and 1965. Appendix C1 describes the selection of this reference building.Appendix C1 also provides detailed information about the selected reference building.64

LIFESPAN OF BUILDINGNormally, the lifespan of a building after renovation is determined by the investor orowner. To gain information about the influence of the lifespan of the building afterrenovation, three life spans are evaluated in this research. The foundation for definingthese three life spans is elaborated in appendix C1. The scenarios for the lifespan of thebuilding that are used in this model application are:Scenario 1:Scenario 2:Scenario 3:25 years50 years75 yearsLIFESPAN OF ELEMENTSThree scenarios are defined for the lifespan of elements and the functional change rate ofthe reference building during its life time. Again, three scenarios are selected to gaininformation about the influence of this boundary condition on the life cycle performanceof a renovation concept.Scenario 1:Scenario 2:Scenario 3:Short lifespan of elements & high functional change rateExpected lifespan of elements & expected functional change rateLong lifespan of elements & low functional change rateThe technical lifespan of elements differs. Therefore, different life spans are defined forthe elements of the three renovation concepts. The defined life spans and functionalchange rates are elaborated in appendix C1.5.3 MODEL OUTPUT - COMPOSITION AND CORRELATIONNow the input parameters of the boundary conditions are defined, the model is applied.This paragraph provides the output of the model application. Due to the large amount ofoutput information, only the most interesting figures are provided. Other model outputinformation is provided in appendix C3. The input that is used to determine these outputinformation is provided in appendix C2.ANALYSIS 1: COMPOSITION OF LIFE CYCLE COSTSTo identify possible correlations between the life cycle costs and other factors ofinfluence, the composition of the life cycle costs of each renovation alternative isanalyzed in this section.NO RENOVATIONFigure 42 shows the composition of the life cycle costs for the alternative „no renovation‟.Six scenarios are presented to show the differences in composition.Initial investment boilerInitial investment radiatorsOperating costsMaintenance costsDisposal costsChange over costsCosts for replacement of elementsLEGEND: SCENARIO [A.B.C.D.]A=1A=2A=3B=1B=2B=3NO RENOVATIONSTANDARD RENOVATIONWARMBOUWEN RENOVATION+25 YEARS EXPLOITATION+50 YEARS EXPLOITATION+75 YEARS EXPLOITATIONC=1C=2C=3D=1LOW FUNCTIONAL LIFESPAN/HIGHCHANGE RATEEXPECTED FUNCTIONAL LIFESPAN/EXPECTED CHANGE RATEHIGH FUNCTIONAL LIFESPAN/LOWCHANGE RATE+5% ENERGY PRICESFIGURE 42 - COMPOSITION LCC 'NO RENOVATION'D=2 +8% ENERGY PRICESD=3 +11% ENERGY PRICES65

The scenario with the lowest contribution of the operating costs is scenario 1.1.1.1. Inthis scenario, the operating costs contribute for 72% to the total life cycle costs.The most plausible and expected scenario isscenario 1.2.2.2. The composition of the lifecycle costs is presented in figure 43.Figures 42 & 43 point out that the maincontributor for the „life cycle costs‟ at the norenovation alternative is the factor „operatingcosts‟. For the scenarios with an exploitationperiod of 75 years, the contribution ofoperating costs can increase to 99% of theaverage yearly life cycle costs.Scenario 1.2 .2 .2 Euro %Initial investment boiler 254 2%Initial investment boiler radiators 211 2%Operating costs 10160 92%M aintenance costs 145 1%Disposal costs 5 0%Change over costs 78 1%Costs for replacement of elements 236 2%Total LCC (per year) 11089 100%FIGURE 43 - COMPOSITION LCC SCEN ARIO 1.2.2.2STANDARD RENOVATIONFigure 44 shows the composition of the life cycle costs for the „standard renovation‟alternative.Initial investment boilerInitial investment radiatorsInitial investment roof insulationInitial investment floor insulationInitial investment facade insulationCosts for windowsInitial investment mechanical ventilationOperating costsMaintenance costsDisposal costsChange over costsReplacement costs of elementsFIGURE 44 – COMPOSITION LCC „STANDARD RENOVATION‟LEGEND: SCENARIO [A.B.C.D.]A=1A=2A=3B=1B=2B=3C=1C=2C=3D=1D=2NO RENOVATIONSTANDARD RENOVATIONWARMBOUWEN RENOVATION+25 YEARS EXPLOITATION+50 YEARS EXPLOITATION+75 YEARS EXPLOITATIONLOW FUNCTIONAL LIFESPAN/HIGHCHANGE RATEEXPECTED FUNCTIONAL LIFESPAN/EXPECTED CHANGE RATEHIGH FUNCTIONAL LIFESPAN/LOWCHANGE RATE+5% ENERGY PRICES+8% ENERGY PRICESD=3 +11% ENERGY PRICESAt the „standard renovation‟ alternative, the contribution of the operating costs is lowerthan at the no renovation alternative. At scenario 2.1.1.1 the contribution of theoperating costs is 48%. The composition of the life cycle costs for the expected scenario(2.2.2.2) is presented in figure 45.Scenario 2.2.2.2 Euro %Initial investment boiler 349 3%Initial investment radiators 211 2%Initial investment roof insulation 296 3%Initial investment floor insulation 86 1%Initial investment facade insulation 147 1%Initial investment windows 229 2%Initial investment mech. ventilation 360 3%Operating costs 8168 79%Maintenance costs 233 2%Disposal costs 5 0%Change over costs 78 1%Costs for replacement of elements 216 2%Total LCC (per year) 10378 100%FIGURE 45 - COMPOSITION LCC SCENARIO 2.2.2.2Figures 44 & 45 show that the factor„operating costs‟ is the main contributorfor the life cycle costs at the standardrenovation alternative. However, thecontribution of this factor is 13% lowerthan in case of the „no renovation‟alternative at scenario x.2.2.2.66

WARMBOUWEN RENOVATIONFigure 46 shows the composition of the life cycle costs for the alternative WarmBouwenrenovation.Initial investment heat pumpInitial investment acquiferInitial investment wall heating systemInitial investment roof insulationCosts for windowsOperating costsMaintenance costsDisposal costsChange over costsReplacement costs of elementsFIGURE 46 - COMPOSITION LCC 'WARMBOUWEN RENOVATIO N‟LEGEND: SCENARIO [A.B.C.D.]A=1A=2A=3B=1B=2B=3C=1C=2C=3D=1D=2NO RENOVATIONSTANDARD RENOVATIONWARMBOUWEN RENOVATION+25 YEARS EXPLOITATION+50 YEARS EXPLOITATION+75 YEARS EXPLOITATIONLOW FUNCTIONAL LIFESPAN/HIGHCHANGE RATEEXPECTED FUNCTIONAL LIFESPAN/EXPECTED CHANGE RATEHIGH FUNCTIONAL LIFESPAN/LOWCHANGE RATE+5% ENERGY PRICES+8% ENERGY PRICESD=3+11% ENERGY PRICESAt the WarmBouwen renovation concept, the contribution of operating costs is 49% inscenario 3.1.1.1. At this scenario, the investment in the heat pump is also significantwith 18% contribution. The composition of the life cycle costs for the expected scenario(3.2.2.2) is presented in figure 47.Scenario 3.2.2.2 Euro %Initial investment heat pump 678 7%Initial investment acquifer 241 2%Initial investment wall heating system 256 3%Initial investment roof insulation 296 3%Initial investment windows 229 2%Operating costs 7698 79%Maintenance costs 156 2%Disposal costs 5 0%Change over costs 78 1%Replacement costs of elements 77 1%Total LCC (per year) 9714 100%FIGURE 47 - COMPOSITION LCC SCENARIO 3.2.2.2LEGEND: SCENARIO [A.B.C.D.]LOW FUNCTIONAL LIFESPAN/HIGHCHANGE RATEEXPECTED FUNCTIONAL LIFESPAN/EXPECTED CHANGE RATEHIGH FUNCTIONAL LIFESPAN/LOWCHANGE RATELike at the other alternatives, the factor „operating costs‟ is the most contributing factor.At the WarmBouwen alternative the investment for the heat pump during the life cycle isalso significant and contributes for 7% to the life cycle costs of the concept.The performance on the life cycle costs of a renovation alternative is influenced bychanging boundary conditions. The influence of changing boundary conditions on theperformance of the alternatives on life cycle costs is analyzed below.LIFESPAN OF ELEMENTS/FUNCTIONAL CHANGE RATETo determine the influence of this factor on the life cycle costs, the impact of a changefor this boundary condition from “low lifespan of elements/high change rate” into “highlifespan of elements/low change rate” is identified.The difference on the performance on life cycle costs due to a change of the factor“lifespan of elements/change rate” is- between 1% and 9% for all the three renovation alternatives.DEVELOPMENT ENERGY PRICESTo determine the influence of this factor on the life cycle costs, the impact of a changefor this boundary condition from “low increase of energy prices” (=5% per year) into“high increase of energy prices” (=11% per year) is identified.The difference on the performance on life cycle costs due to a changing factor“development energy prices” is- between 43% and 91% for alternative „no renovation‟- between 34% and 89% for alternative „standard renovation‟- between 34% and 89% for alternative „WarmBouwen renovation‟A=1A=2A=3B=1B=2B=3C=1C=2C=3D=1D=2NO RENOVATIONSTANDARD RENOVATIONWARMBOUWEN RENOVATION+25 YEARS EXPLOITATION+50 YEARS EXPLOITATION+75 YEARS EXPLOITATION+5% ENERGY PRICES+8% ENERGY PRICESD=3 +11% ENERGY PRICES67

It can be concluded that the development of the energy prices has a very big impact onthe performance on life cycle costs of the alternatives. The development of the energyprices influences the factor „operating costs‟. The factor „operating costs‟ has the largestinfluence on the life cycle costs. Therefore, a changing development of the energy priceshas a big influence on the performance on life cycle costs.ANALYSIS 2: CORRELATIONS LIFE CYCLE COSTSAnalysis 1 shows that the factor „operating costs‟ is very important for the life cycle costsof a renovation concept. The factor „operating costs‟ consists of costs for electricity useand gas use during the life cycle of a house. The demand for gas and electricity stronglydepends on the energy performance coefficient (EPC) of a house. There is a correlationbetween the energy performance and the life cycle costs of a renovation concept. Figure48 shows the relationship between the energy performance coefficient and the operatingcosts. Another conclusion is that the „no renovation‟ alternative is more susceptible tochanges in the energy prices than the „standard‟ & „WarmBouwen renovation‟alternatives.No renovation StandardrenovationWarmBouwenrenovationEPC 2.22 1.23 0,70Initial operating costs 2014 1619 1526FIGURE 48 - INFLUENCE OF EPC ON OPERATING COSTSThis correlation factor means that if the EPC decreases with 10% (performance isimproved), than the initial operating costs decreases with 6,9% (performance isimproved).This correlation only counts for alternatives with a comparable installation forinterior climate control, and insulation or more efficient installations are used to improvethe EPC. The WarmBouwen concept for example, uses electricity for the production ofheat and cold. The production of one MJ of heat with electricity is more expensive thanthe production of one MJ of heat with natural gas. Therefore, the stated correlationbetween the EPC and operating costs does not apply when the alternative „WarmBouwen‟is compared with „no renovation‟ or „standard renovation‟. However, the statedcorrelation points out that there is a significant correlation between the EPC and the LCC.ANALYSIS 3: COMPOSITION OF LIFE CYCLE YIELDSAn extensive elaboration of the factor „life cycle yields‟ is outside the scope of thisresearch. A basic analysis of this factor results in an approximate composition of thisfactor. Appendix C3.2 shows the approximate composition of this factor.ANALYSIS 4: CORRELATIONS LIFE CYCLE YIELDSThe correlation between the energy performance coefficient and the primary returns isidentified by analyzing the impact of new WWS that will be implemented in 2011, on thelife cycle yields of a house. Figure 49 shows the points that are assigned to a house,based on the energy performance of a house. For this analysis assumption #80,appendix S is made.68

EnergyEPC EPC (average) Rental points Rental priceperformance(label)A++ < 0.50 - 44 713.25A+ 0.51-0.70 0.6 40 695.25A 0.71-1.05 0.88 36 677.25B 1.06-1.30 1.18 32 659.25C 1.31-1.60 1.45 22 608.75D 1.61-2.00 1.8 14 578.25E 2.01-2.40 2.2 8 551.25F 2.41-2.90 2.65 4 533.25G >2.90 - 0 515.25FIGURE 49-IMPACT OF ENERGY PERFORMANCE ON RENTAL POINTS (WWS, 2010)One rental point leads to an average rental increase of 4,5 €/month (WWS, 2010). Thecalculation below shows the average correlation between energy performance coefficientand the rental price.This correlation factor means that if the EPC decreases with 10% (performance isimproved), than the initial operating costs increases with 4,2% (performance isimproved).ANALYSIS 5: COMPOSITION OF LIFE CYCLE ENVIRONMENTAL IMPACTTo identify possible correlations between the life cycle environmental impact and otherfactors of influence, the composition of the life cycle environmental impact of eachrenovation alternative is analyzed in this section.NO RENOVATIONLEGEND: SCENARIO [A.B.C.D.]A=1A=2A=3B=1B=2B=3C=1C=2C=3D=1D=2NO RENOVATIONSTANDARD RENOVATIONWARMBOUWEN RENOVATION+25 YEARS EXPLOITATION+50 YEARS EXPLOITATION+75 YEARS EXPLOITATIONLOW FUNCTIONAL LIFESPAN/HIGHCHANGE RATEEXPECTED FUNCTIONAL LIFESPAN/EXPECTED CHANGE RATEHIGH FUNCTIONAL LIFESPAN/LOWCHANGE RATE+5% ENERGY PRICES+8% ENERGY PRICESD=3 +11% ENERGY PRICESFIGURE 50 - COMPOSITION ENVIRONMENT AL IMPACT 'NO RENOVATION'Figure 50 shows that the gas use during the life cycle of a building causes between 67%& 79% of the total environmental impact. This makes gas use by far the largestcontributor of environmental impact at the no renovation alternative. The impact of theother categories is significant but relative low.69

STANDARD RENOVATIONLEGEND: SCENARIO [A.B.C.D.]A=1NO RENOVATIONA=2STANDARD RENOVATIONA=3WARMBOUWEN RENOVATIONB=1+25 YEARS EXPLOITATIONB=2+50 YEARS EXPLOITATIONB=3+75 YEARS EXPLOITATIONC=1C=2C=3D=1LOW FUNCTIONAL LIFESPAN/HIGHCHANGE RATEEXPECTED FUNCTIONAL LIFESPAN/EXPECTED CHANGE RATEHIGH FUNCTIONAL LIFESPAN/LOWCHANGE RATE+5% ENERGY PRICESD=2+8% ENERGY PRICESFIGURE 51 - COMPOSITION ENVIRONMENTAL IMPACT 'STANDARD RENOVATION'D=3+11% ENERGY PRICESThe contribution on environmental impact per category at the „standard renovation‟alternative is more equally divided, as presented in figure 51. Again gas use is the largestcontributor of environmental impact, with impact scores between 38% & 50%. However,the pie-charts in figure 51 also show that the impact of the assembly of elements andelectricity use has become important. The impact percentages are between 23% & 33%for assembly. The impact of electricity use is between 17% & 23%. The impact of thedisposal of material remains relative low, with impact percentages between 4% and12%.WARMBOUWEN RENOVATIONLEGEND: SCENARIO [A.B.C.D.]A=1NO RENOVATIONA=2A=3B=1STANDARD RENOVATIONWARMBOUWEN RENOVATION+25 YEARS EXPLOITATIONB=2+50 YEARS EXPLOITATIONB=3+75 YEARS EXPLOITATIONC=1C=2C=3D=1LOW FUNCTIONAL LIFESPAN/HIGHCHANGE RATEEXPECTED FUNCTIONAL LIFESPAN/EXPECTED CHANGE RATEHIGH FUNCTIONAL LIFESPAN/LOWCHANGE RATE+5% ENERGY PRICESD=2+8% ENERGY PRICESD=3 +11% ENERGY PRICESFIGURE 52 - COMPOSITION ENVIRONMENTAL IMPACT 'WARMBOUWEN RENOVATION'The composition of the environmental impact of the WarmBouwen concept differs fromthe „no renovation‟ and „standard renovation‟ concept. At these alternatives theenvironmental impact by assembly of materials and elements has become the mostimportant impact category with impact percentages between 33% & 46% (Figure 52).The impact of electricity for interior climate regulation scores between 26% & 35%.Electricity use scores between 5 & 23%. The disposal of materials is a significant factor ofinfluence at the WarmBouwen concept, with impact percentages between 9% & 23%.This analysis shows that the assembly and disposal of materials and elements becomemore significant when the total environmental impact decreases. Thus, the lower thetotal environmental impact of a concept due to lower impact from energy use, the higherthe significance of assembly and disposal of materials. Therefore, it also can beconcluded that the factor „life cycle environmental impact‟ is very relevant at determiningthe performance of sustainable renovation concepts. If only the factor „energyperformance coefficient‟ is used for determining sustainability, the impact of appliedmaterials is not taken into account. The analysis above shows, that this impact ofmaterials is significant, especially when energetic concepts are improved.The performance on the life cycle environmental impact of a renovation alternative isinfluenced by changing boundary conditions. The influence of changing boundaryconditions on the performance of the alternatives on life cycle environmental impact isanalyzed below.70

Lifespan of elements/functional change rateA change of the factor “lifespan of elements/change rate” influences the performance onenvironmental impact of the alternatives. The influence of this factor is:- 13,5 - 15,6% at no renovation- 15,9 - 19,8% at standard renovation- 18,0 - 25,4% at WarmBouwen renovation.This means that for „no renovation‟ the environmental impact increases between 13,5 &15,6 % if the factor “lifespan of elements/functional change rate” changes from low/highto high/low.Lifespan of buildingA change of the factor “lifespan of building” influences the performance on environmentalimpact of the evaluated alternatives. The influence of this factor is:- 0,4 – 1.2% at no renovation- 5,2 - 10,2% at standard renovation- 0,7 – 10,7% at WarmBouwen renovation.This means that for „no renovation‟ the environmental impact increases between 0,4 &1,2 % if the factor “lifespan of building” changes from 25 years to 75 years.ANALYSIS 6 – CORRELATIONS LIFE CYCLE ENVIRONMENTAL IMPACTThere is a correlation between the EPC and the LCEI. Principally this relation is a positiverelation, which means that if the EPC decreases (performs better), the LCEI alsodecreases (performs better). This relation is indicated on the basis of the performance ofthe three renovation alternatives in this research. Figure 53 shows the performances onEPC and LCEI of the three alternatives at scenario x.2.2.2.No renovation Standard renovation WarmBouwenrenovationEPC 2.22 1.23 0.70LCEI 756 592 393FIGURE 53 - PERFORMANCES ON EPC AND LCEI (SCENARIO X.2.2.2)Figure 53 points out that the environmental impact decreases if the EPC decreases.However, to quantify the correlation between these two factors, more data is required. Alinear correlation can be identified if the impact of applied materials at the improvementof the EPC is neglected. However, it is impossible to improve the EPC of a house, withoutapplying measures that comprise physical materials. This model application only pointsout that there is a positive relation between the EPC en the LCEI of renovationalternatives.Figure 54 provides an overview of the expected development the EPC, LCC & LCEI.improvingperformanceEnvironmental impactLife cycle costsEnergy performance coefficientFIGURE 54 - EXPECTED RELATION BETWEEN EPC, LCC, AND LCEIt71

Figure 54 points out that there is an optimum between the life cycle costs, the energyperformance and the life cycle environmental impact; the energy performance coefficientis bounded to a maximum performance. Principally, the life cycle costs will decrease ifthe EPC is decreased. However, there is a point whereby the extra investment is notfeasible from an economic point of view anymore. From that point, a trade-off has to bemade between LCC and LCEI. The question that could be stated at this point is: What isthe value of lower environmental impact?ANALYSIS 7 – COMPOSITION AND CORRELATIONS QUALITYThe performance of the alternatives on the aspect quality is composed by the sub factorsuser health, user quality, and future oriented facilities, see figure 55. As described inappendix C2.2, it is plausible that there is a correlation between the experienced qualityof a house and the life cycle yields. However, this correlation is quite complex to defineand is out of the scope of this research.HealthUser qualityFuture valueWeightingfactorNorenovationPointsStandardrenovationANALYSIS 8 – COMPOSITION AND CORRELATIONS EPCpointsWarmBouwenrenovationPointsSound 250 4,6 11,5 4,9 12,3 4,9 12,3Air quality 450 4,9 22,1 6,5 29,3 6,1 27,5Thermal comfort 250 5,8 14,5 6,6 16,5 7,5 18,8Visual comfort 50 6 3,0 6 3,0 6 3,0Technical quality 250 7,4 18,5 7,4 18,5 7,4 18,5Future facilities 333 4,7 15,7 4,7 15,7 5,3 17,6Flexibility 333 5,7 19,0 5,7 19,0 6,1 20,3Experienced value 333 6 20,0 6 20,0 6,2 20,6Total scoreNormalized scoreFIGURE 55 - COMPOSITION AND OUTPUT ON QUALITY124,20,90The performance of the alternatives on the aspect EPC is composed by constructive andinstallation technical characteristics of a house. There is no influence of one of the otherfour main factors of influence on the performance on the factor EPC. However, the EPCdoes influence the LCC and LCEI. The correlations between these factors are described inanalysis 2 and analysis 6.134,10,97138,6172

5.4 MODEL OUTPUT - PERFORMANCE OF WARMBOUWENANALYSIS 9: PERFORMANCE ON LIFE CYCLE COSTSThe most plausible scenario in this research isscenario x.2.2.2. The performance on life cyclecosts of the three evaluated renovationalternatives is presented in figure 56. Thefigure shows that the WarmBouwen conceptscores best on the aspect of life cycle costs atscenario x.2.2.2.1EPCLCC1LCY1The scenario with the best performance on thefactor „life cycle costs‟ is scenario 1.1.3.1.Based on this analysis, it appears that norenovation is the most attractive alternative.However, figure 56 also shows that althoughthe life cycle costs of no renovation is the bestat scenario x.1.3.1, the performance on theother four performance indicators is the worst.Whether the financial feasibility of thisalternative is the best can be questioned,because the performance on life cycle yields ofthe „standard‟ and „WarmBouwen‟ alternativeare better than the performance on life cycleyields of „no renovation‟. Next to that, the performance on the aspects quality andenvironmental impact of the „standard renovation‟ and „WarmBouwen renovation‟alternative are better than the performance of the „no renovation‟ alternative.Figure 57 shows the results of the analysis on the performance on life cycle costs.Performance „no renovation‟better than „standardrenovation‟ in the scenariosPerformance „no renovation‟better than „WarmBouwenrenovation‟ in the scenariosPerformance „WarmBouwen‟better than performance„standard renovation‟x.1.1.1 x.1.1.1 All scenarios.x.1.1.2x.1.1.2x.1.1.3x.1.2.1x.1.2.1x.1.2.2x.1.2.2x.1.3.1x.1.2.3x.1.3.2x.1.3.1x.1.3.2x.1.3.3x.2.1.1x.2.2.1FIGURE 57 - PERFORMANCES ON LIFE CYCLE COSTSFIGURE 56 - LIFE CYCLE PERFORMANCE SCENARIOX.2.2.2More output information on the factor of influence „life cycle costs‟ is provided inappendix C.3.1.1QScenario x.2.2.2- lifespan building: +50 years- lifespan elements/change rate: expected- Increase energy price: +8%1LCEINo renovationStandard renovationWarmBouwen renovation73

ANALYSIS 10: PERFORMANCE ON LIFE CYCLE ENVIRONMENTAL IMPACTFigure 58 presents the life cycle performanceof the alternatives at scenario x.3.3.2. TheWarmBouwen alternative has the bestperformance on the aspect life cycleenvironmental impact at all scenarios, thestandard renovation alternative scores secondbest at all scenarios and the no renovationalternative scores worst. The scenario with thebest performance on the factor „life cycleenvironmental impact‟ is scenario 3.3.3.x.1EPCLCC1LCY1More output information on the factor ofinfluence „life cycle environmental impact‟ isprovided in appendix C.3.3.1Q1LCEIScenario x.3.3.2- lifespan building: +75 years- lifespan elements/change rate: high/low- Increase energy price: +8%No renovationStandard renovationWarmBouwen renovationFIGURE 58 - LIFE CYCLE PERFORMANCE SCENARIOX.3.3.2ANALYSIS 11: PERFORMANCE ON LIFE CYCLE YIELDS1LCCAn extensive elaboration of the life cycle yields isoutside the scope of this research. However, theresults of the approximate life cycle yieldscalculation point out that the life cycle yieldsperformance of a renovation concept mainlyLCY11depends on primary returns, which is the rent ofEPCthe house. The new “woning waarderingsstelsel”(WWS) that will be implemented in theNetherlands in 2011 assigns points to a buildingbased on the energy performance. A housingcorporation can increase the rent of a house, if theenergy performance of the house is improved.Therefore, the energy performance coefficient willbe an important factor for the life cycle yields of aLCEI11Qhouse.Scenario x.2.2.2No renovation- lifespan building: +50 yearsStandard renovationAs a result, the life cycle yields calculation shows - lifespan elements/change rate: expected- Increase energy price: +8%WarmBouwen renovationthat the „WarmBouwen renovation‟ alternative hasFIGURE 59 - PERFORMANCE ON LIFE CYCLEthe best performance on life cycle yields. The YIELDS„standard renovation‟ alternative scores second best. Lastly, the „no renovation‟alternative scores the worst on life cycle yields. These results are presented in figure 59.More output information on the factor of influence „life cycle yields‟ is provided inappendix C.3.2.74

ANALYSIS 12: PERFORMANCE ON QUALITY.Figure 60 presents the composition and output of the factor of influence „quality‟.HealthUser qualityFuture valueWeightingfactorFIGURE 60 - COMPOSITION AND SCORE ON QUALITYNorenovationPointsStandardrenovationpointsWarmBouwenrenovationPointsSound 250 4,6 11,5 4,9 12,3 4,9 12,3Air quality 450 4,9 22,1 6,5 29,3 6,1 27,5Thermal comfort 250 5,8 14,5 6,6 16,5 7,5 18,8Visual comfort 50 6 3,0 6 3,0 6 3,0Technical quality 250 7,4 18,5 7,4 18,5 7,4 18,5Future facilities 333 4,7 15,7 4,7 15,7 5,3 17,6Flexibility 333 5,7 19,0 5,7 19,0 6,1 20,3Experienced value 333 6 20,0 6 20,0 6,2 20,6Total scoreNormalized score124,20,90134,10,97138,61Figure 60 shows that at most quality aspects,there are minor differences between thealternatives. The „standard renovation‟alternative scores the best on the aspect airquality. The „WarmBouwen renovation‟alternative is slightly better on all otheraspects and scores significantly better on theaspect thermal comfort.1EPCLCC1LCY1The quality of a renovation alternative is notinfluenced by changing boundary conditions.Therefore, the score on the quality aspect isequal at all defined scenarios. Theperformance on the factor „quality‟ ispresented in figure 61.More output information on the factor ofinfluence „quality´ is provided in appendixC.3.4.1QScenario x.2.2.2- lifespan building: +50 years- lifespan elements/change rate: expected- Increase energy price: +8%FIGURE 61 - PERFORMANCE ON QUALITY AND EPC1LCEINo renovationStandard renovationWarmBouwen renovationANALYSIS 13: PERFORMANCE ON ENERGY PERFORMANCE COEFFICIENTFigure 62 presents output on the factor „energy performance coefficient‟.No renovation Standard renovation WarmBouwenrenovationEnergy performance 2.22 1.23 0.7coefficientNormalized score 0.32 0.57 1FIGURE 62 – EPC OUTPUT75

The EPC output is determined by constructive and installation technical characteristics ofthe renovation alternatives. The EPC is not influence by changing boundary conditions.Therefore, the score on the „energy performance coefficient‟ is equal at all definedscenarios. The „WarmBouwen renovation‟ alternative scores best on the factor EPC, the„standard renovation‟ alternative scores second best, the „no renovation‟ alternativescores worst on this factor.More output information on the factor of influence „quality´ is provided in appendix C.3.5.ANALYSIS 14: OVERALL LIFE CYCLE PERFORMANCEThe performances and correlations of all main factors of influence are described inanalyses 1-13 . Now, the question is: What is the overall life cycle performance of eachalternative. There is no one-sided answer on this question, because the performance of aconcept strongly depends on the interest of the owner. A real estate investor has otherinterests than a housing corporation. A real estate developer that develops a new headquarter for Greenpeace may have other interests than a real estate developer thatdevelops a new head quarter for a financial instance. Therefore, a suggestion for thedetermination of the life cycle performance in one single indicator is given in paragraph6.3, page 81.Based on the individual scores of the evaluated renovation alternatives on the mainfactors of influence, it can be concluded that:- The „WarmBouwen renovation‟ alternative scores better on the aspect of life cyclecosts than the „standard renovation‟ alternative, on all defined scenarios.- The „WarmBouwen renovation‟ alternative scores best on the aspect of life cycleenvironmental impact, on all defined scenarios. The „standard renovation‟ alternativescores second best. The „no renovation‟ alternative scores worst.- The „WarmBouwen renovation‟ alternative scores best on the aspect of life cycleyields, on all defined scenarios. The „standard renovation‟ alternative scores secondbest. The „no renovation‟ alternative scores worst.- The „WarmBouwen renovation‟ alternative scores best on the aspect of quality, on alldefined scenarios. The „standard renovation‟ alternative scores second best. The „norenovation‟ alternative scores worst.- The „WarmBouwen renovation‟ alternative scores best on the aspect energyperformance coefficient, on all defined scenarios. The „standard renovation‟alternative scores second best. The „no renovation‟ alternative scores worst.- The „no renovation‟ alternative scores better on the aspect life cycle costs than the„standard renovation‟ alternative at all scenarios with a lifespan of building of 25years and at all scenarios with a lifespan of building of 50 years, and a low increase ofthe energy price. On all other scenarios, the „standard renovation‟ alternative scoresbetter on the aspect life cycle costs than the „no renovation‟ alternative.- The „no renovation‟ alternative scores better on the aspect life cycle costs than the„WarmBouwen renovation‟ alternative at all scenarios with a lifespan of building of 25years, and a development of the energy prices of 5% or 8%. On all other scenarios,the „WarmBouwen renovation‟ alternative scores better on the aspect life cycle coststhan the „no renovation‟ alternative.All the overall output performances are provided in appendix C.4.76

5.5 IMPROVEMENTS FOR WARMBOUWENIMPROVEMENT 1 – APPLYING INDIVIDUAL GAS HEAT PUMPThe WarmBouwen concept as defined in this research makes use of an individual electricheat pump for the generation of heat and cold. When a gas heat pump is used for thegeneration of heat and cold, the performance of the concept is significantly improved onthe factor „life cycle costs‟.Currently, an individual gas heat pump for a house does not exist. Thus, thisimprovement is not directly applicable. However, the heat pump market is subject tomajor developments and improvements. Therefore, it is plausible that individual gas heatpumps will be available in future.IMPACT ON PERFORMANCEThe impact on the life cycle performance of a gas heat pump is presented in figure 63.LCC LCY LCEI Q EPCWarmBouwen as is 9714 1 393 138,6 0,7WarmBouwen with gasheat pump 6041 0,98 390 138,6 1,02Impact on performance 38% 3% 0% 0% 46%FIGURE 63 - IMPACT OF GAS HEAT PUMP ON LIFE CYCLE PERFORMANCEApplying a gas heat pump instead of an electric heat pump has a very positive influenceon the performance on life cycle costs of the WarmBouwen concept. The performanceimproves with 38%. This results from the fact that currently it is cheaper to produce 1 MJof heat or cold with gas than to produce 1 MJ of heat or cold with electricity. The energyperformance coefficient is negatively influenced by the application of a gas heat pump.The performance on this aspect deteriorates with 46%. The performance on life cycleyields is negatively influenced. This is the result of the decreased performance on theenergy performance coefficient. The aspects life cycle environmental impact and qualityare not influenced by this improvement.It can be questioned whether this measure is an improvement of the WarmBouwenconcept. This depends on the interests of the owner. If there is a strong focus oneconomic performance, it is plausible that the measure is considered to be animprovement. Other interest can lead to other interpretations.Appendix N provides an elaboration of the impact evaluation of a gas heat pump on thefive main factors of influence.IMPROVEMENT 2 – APPLY SUSTAINABLE SOLAR ENERGY SYSTEMSThe WarmBouwen concept can be approved by applying sustainable solar energysystems like PV-cells or a solar heating system. The WarmBouwen concept useselectricity as energy source for interior climate regulation. Therefore, the production of aPV-cell can directly be used for interior climate regulation.A solar heating system also contributes significantly. A solar heating system can be usedto produce warm tap water. This decreases the demand for warm tap water from theheat pump and thereby contributes to the sustainable performance of the concept. Anadditional advantage of the solar heating system is that the efficiency of a heat pumpdecreases if the production temperature increases. Thus, the efficiency of a heat pump islower at producing warm tap water (approximately 65 degrees Celsius) than at producingwater for interior climate control (lower than 35 degrees Celsius). The effect of a solarheating system is two dimensional. First, it takes away a part of the primary demand forhigh temperature water. Secondly, it contributes to the efficiency of the heat pump.77

IMPACT OF IMPROVEMENT ON PERFORMANCEThe impact on the life cycle performance of the two solar energy systems is presented infigure 64.LCC LCY LCEI Q EPCWarmBouwen as is 9714 0,97 393 138,6 0,7WarmBouwen withsolar systems 7771 1 343 138,6 0,46Impact on performance 20% 3% 13% 0% 34%FIGURE 64 - IMPACT OF SOLAR ENERGY SYSTEMS ON LIFE CYCLE PERFORMANCEThe solar energy systems have a positive influence on the aspect life cycle costs. Theproduction of the PV-cells is directly used by the heat pump for interior climate control.The impact of the solar energy systems on the life cycle costs is quite high. This isbecause the factor „operating costs‟ (costs due to energy use) is the main contributor onthe average yearly life cycle costs. A significant decrease of this factor, results in asignificant decrease of life cycle costs. As described before, the efficiency of a heat pumpdecreases if the production temperature increases. The solar heating system produceswater with a high temperature, which can be used for warm tap water. Therefore thissystem not only decreases the primary energy demand, but also contributes to theefficiency of the heat pump.Appendix N provides an elaboration of the impact evaluation of solar energy systems onthe five main factors of influence.IMPROVEMENT 3 – APPLY FLEXIBLE INTERNAL WALLSThe WarmBouwen concept can be approved by applying flexible internal walls instead offixed internal walls. This improvement only influences the aspect life cycle environmentalimpact significantly. Therefore, this is the only factor of influence that is elaborated inmore detail.IMPACT OF IMPROVEMENT ON PERFORMANCEThe impact on the life cycle performance of a gas heat pump is presented in figure 65.LCC LCY LCEI Q EPCWarmBouwen as is 9714 1 451 138,6 0,7WarmBouwen withflexible internal walls 9714 1 380 138,6 0,7Impact on performance 0% 0% 16% 0% 0%FIGURE 65 - IMPACT OF FLEXIBLE INTERNAL WALLS ON LIFE CYCLE PERFORMANCEThe application of flexible internal walls has a positive influence on the performance oflife cycle environmental impact. However, the application of flexible internal walls is notalways an improvement. The performance that is presented in figure 65 is theperformance at scenario 3.3.1.x. In this scenario, there is a high lifespan of the buildingand a high functional change rate. Flexible walls also contribute to the quality of theconcept, because a building is better adjustable for other functions than housing. Also, abuilding is is better capable of catering to the wishes of its occupants. However,elaboration of the application of flexible walls does not influence the quality of theconcept according to the software of GPR-Gebouw. The flexible internal walls do notsignificantly influence the performance on life cycle costs, life cycle yields, and energyperformance coefficient.Appendix N provides an elaboration of the impact evaluation of flexible internal walls onthe factor „life cycle environmental impact‟.78

6. DISCUSSIONThis chapter provides a discussion on the research results. First, the development of themodel and the model itself are discussed in paragraph 6.1. After that, the output frommodel application is subject to discussion in the paragraphs 6.2 and 6.3.6.1 MODELThe reliability of the model is not only optimized by selecting experts with specialistknowledge of- and experience with sustainability and sustainable real estate, but also byselecting experts with different backgrounds. This provides useful information fromvarious points of view, which makes the model more generic and complete. To collectdetailed and relevant knowledge, specialists on each specific main factor of influence areinterviewed. Thus, specialists on life cycle costs, life cycle yields, environmental impact,quality, and energy performance coefficient are interviewed to gather information for themodel development.Each factor of influence that is integrated in the model is mentioned as a factor ofinfluence by several respondents. Thus, the integrated factors of influence are initiallymentioned and validated several times in other interviews by specialists with differentbackgrounds. This proves that the factors of influence are relevant and considered to beimportant at the determination of the performance of sustainable renovation concepts.Beside the executed interviews, current sustainability assessment tools are analyzed andused as references to identify factors of influence on the performance of sustainablerenovation concepts. These current tools are up-to-date, applied on large scale in theNetherlands, and developed by specialized agencies and therefore are reliable as a basisfor the development of the model.Next to the existing sustainability assessment tools, also the executed interviews wereimportant for the identification of factors of influence. The information that is gatheredduring the interviews mainly resulted in the insight that the combination of economicperformance and sustainable performance is very important regarding theimplementation of sustainable concepts and products. This observation corresponds intolarge extend with relevant information from the scientific researches of Norris (2001),and Kicherer, et al. (2007). This correspondence contributes to the reliability of theidentified aspects.Chapter four describes that the developed model can be used by parties with aneconomical interest in real estate, by sustainable concept developers, and by individualhouse owners. However, it can be questioned whether it is worth the time and money toperform an evaluation of renovation concepts for an individual house owner. It is moreplausible that interest groups for individual house owners spend time and money on theevaluation of renovation measures and concepts for a specific type of dwelling, to provideinformation for the members of the interest group. In that case, the evaluation is usefulfor a larger public.79

6.2 MODEL APPLICATIONThe model application comprises the application of the developed “life cycle performanceevaluation model”, on the selected renovation alternatives and the selected referencebuilding.For the application of the model, a lot of calculations are executed. The input that isrequired for the execution of the model application is provided by experts during expertconsultations. Besides that, the output of the model application is checked by expertsafterwards. The involvement of these experts at the model application contributes to thereliability of the model application. The experts that are consulted and the informationthat is provided by these experts are presented in appendix D.Next to the expert consultations, two case studies are executed to gather inputinformation for the model application. The projects that are analyzed at the case studiesare recently executed and therefore provide reliable and actual information.The calculations that are executed for the model application are made with professionalsoftware tools. The used software tools are developed by specialized agencies and areapplied on large scale at a professional level. Therefore, the calculation methods of thesoftware tool are considered to be reliable. Figure 66 presents information about theused software tools.Factor of influenceSoftware toolLife cycle costsLCC-LiteLife cycle yields -Life cycle environmental impactSimaProQualityGPR-GebouwEnergy performance coefficientEPWFIGURE 66 - USED SOFTWARE TOOLS AT MODEL APPLICATIONThe input parameters of the model are largely based on expert information, technicaldata sheets, the equivalence principle, or reliable website information. For some inputparameters assumptions are made. These assumptions may have a negative influence onthe reliability of the output of the model application.6.3 RESULTSDEVELOPMENT ENERGY PRICEFor the development of the energy prices of gas and electricity, three scenarios aredefined. These scenarios are described in figure 67.Development = lower thanexpectedDevelopment = as expected Development = higher thanexpected+5% per year +8% per year +11% per yearFIGURE 67 - THREE SCENARIOS OF DEVELOPMENT ENERGY PRICEAlthough these scenarios are founded on an analysis of the development of the energyprices over the last thirteen years (appendix C2.1), it can be questioned whether or not itis plausible that the energy prices will increase with average 8% per year for the periodof 50 or 75 years. It is impossible to forecast the development of the energy prices andnext to that, technological breakthroughs can even cause a decrease of energy prices inthe future. Although it is plausible that the development of the energy price will beapproximately as defined, there is a degree of uncertainty about this factor.80

SUBSIDY ON SUSTAINABLE CONCEPTSThe results of the model application provide information about the selected renovationalternatives, without acknowledged subsidies. However currently, a lot of subsidies areavailable for sustainable applications and sustainable concepts. At the case “De Tempel”,which is analyzed for this research, several subsidies are acknowledged to theWarmBouwen concept. Also for measures from the „standard renovation‟ concept it isplausible that subsidies are acknowledged at implementation. This improves theperformances of the „standard renovation‟ and „WarmBouwen renovation‟ concepts.SUGGESTION FOR SINGLE SCORE ON LIFE CYCLE PERFORMANCEThe interpretation of the life cycle performance of a renovation concept differs per owner.This is the result of different stakes and interests of the possible involved owners orparties. A real estate investor for example, primary tries to maximize profit. Therefore,the focus will be mainly on the financial feasibility (life cycle costs & life cycle yields) of aconcept. However, a real estate developer that develops a new occupancy for a tenantwith a high degree of urgency for sustainability will focus more on other aspects likeenvironmental impact and quality. This is the main reason why the output of the model isnot presented in a single score, but in the normalized score on the five main factors ofinfluence. The section below presents a suggestion for the determination of one singlescore on the life cycle performance of a renovation concept.For the determination of a single score, a weight factor is assigned to each of the fivemain factors of influence. This weight factor lies between 1 and 10. Hereby, the weightfactor 10 refers to a very high importance of the factor and weight factor 1 refers to avery low importance of the factor. The normalized scores are multiplied by the weightfactor of the factors. The total life cycle performance score is the sum of all weightedscores. Figure 68 presents the single score model output of scenario x.2.2.2.WeightingfactorNormalizedscoreNo renovationWeightedscoreStandard renovationNormalizedscoreWeightedscoreWarmBouwen renovationNormalizedscoreWeightedscoreLCC 5 0,38 1,9 0,41 2,05 0,43 2,15LCY 5 0,8 4 0,92 4,6 1 5LCEI 5 0,446 2,23 0,569 2,845 0,857 4,285Q 5 0,9 4,5 0,97 4,85 1 5EPC 5 0,32 1,6 0,57 2,85 1 5LCP Score 14,2 17,2 21,4FIGURE 68 - SINGLE SCORE ON LIFE CYCLE PERFORMANCE AT SCENARIO X.2.2.2CHANGING IMPORTANCE OF FACTORSAs a result of changing insights and new development, the interpretation of theimportance of factors and sub-factors changes in time. Therefore, the appreciation of thefactors of influence and the score of a concept is dynamic. To explain this point ofdiscussion in more detail, two examples are given.Example 1Due to increasing temperatures in summer, the need for interior cooling of a houseincreases. As a result, this sub-factor is appreciated more than it is currently. The higherappreciation results in a higher score on the aspect „quality‟ and the life cycleperformance of a concept that is capable to provide interior cooling increases.Example 2The main factor of influence „life cycle environmental impact‟ is composed by tencategories. These categories are described in appendix C3.3. At this moment, the impact81

of category „Greenhouse‟ is considered to be an important factor. Therefore, a highweight factor is assigned to this impact category. It is plausible that the importance ofthe various factors will change in time due to new insights. The importance of materialsand energy resources for example, is currently becoming more and more important.RESULTS OF THE EVALUATED ALTERNATIVESThe radar diagrams that visualize the life cycle performances of the evaluatedalternatives on the defined scenarios in this research, suggest that the score on the mainfactors of influence positively influence each other (see appendix C4). In most scenarios,the radar diagram of the „no alternative‟ is the smallest. This alternative scores worst onall five main factors of influence. The „standard renovation‟ alternative mostly scoressecond best on all factors of influence, and the „WarmBouwen renovation‟ alternativescores best at all factors of influence. However, the five main factors of influence are lessinterrelated than is suggested by the output of these renovation alternatives. The outputof the model becomes more interesting if a comparison is made of renovation conceptsthat have approximately the same performance on the factor „energy performancecoefficient‟. In this case measures as flexible walls, an optimal proportion betweenmaterials and insulation capacity, the type of heat and cold production, the usedresources for heat and cold production, and alternative replacement materials becomesmore important to increase the life cycle performance of a sustainable renovationconcept.82

7. CONCLUSIONSIn this chapter the defined research questions are answered. Paragraph 7.1 provides theanswers on the main question and the seven sub questions. These answers put theconclusions of this research together. Paragraph 7.2 provides suggestions for furtherresearch.7.1 CONCLUSIONSMAIN QUESTION:WHAT ARE FACTORS OF INFLUENCE ON THE LIFE CYCLE PERFORMANCE OFA SUSTAINABLE RENOVATION CONCEPT?Based on a literature study, expert interviews, an evaluation of existing sustainabilityassessments tools, and a model test, five main factors of influence on the performance ofa sustainable renovation concept are identified. These main factors of influence are:1. Life cycle costs2. Life cycle yields3. Life cycle environmental impact4. Quality5. Energy performance coefficientNext to these five main factors of influence, boundary conditions have an influence onthe performance of a sustainable renovation concept. The five factors of influence andthe boundary conditions consist of several first- and second level sub factors. Anoverview of the identified sub factors of influence is presented in the developed “life cycleperformance evaluation model” in figure 31, page 53.This research points out that the performance of sustainable renovation concepts isdetermined by a combination of the sustainable performance, the performance onquality, the financial feasibility, and boundary conditions. Hereby, a whole life cycleapproach is essential for a well founded evaluation, because only a life cycle approachprovides a comprehensive view on the performance of a sustainable renovation concept.GENERAL SUB QUESTIONS1. WHAT IS SUSTAINABLE RENOVATION?Sustainable renovation is the process of house adaptation with the goal to increasinglycomply with sustainability aspects. For buildings, the most important sustainabilityaspects are environmental impact, energy, comfort and health, and economicperformance.2. WHAT ARE FACTORS OF INFLUENCE ON THE PERFORMANCE OF ASUSTAINABLE RENOVATION CONCEPT?There are five main factors of influence on the performance of a sustainable renovationconcept. These main factors of influence are:1. Life cycle costs2. Life cycle yields3. Life cycle environmental impact4. Quality5. Energy performance coefficient83

3. WHAT ARE FACTORS OF INFLUENCE ON THE MARKET IMPLEMENTATIONOF AN INNOVATIVE SUSTAINABLE RENOVATION CONCEPT IN THENETHERLANDS?Based on a literature study and expert interviews, five main factors of influence on themarket implementation of an innovative sustainable renovation concept in theNetherlands are identified. These main factors of influence are:1. System change factors2. Adoption of the innovation3. Legislation & rules4. Process & organization5. Technical feasibilityThese five main factors of influence consist of several first- and second level sub factors.An overview of the identified sub factors is presented in the developed implementationmodel for sustainable renovation concepts in figure 17, page 31.4. WHAT IS THE COMPOSITION OF- AND CORRELATION BETWEEN THEIDENTIFIED FACTORS OF INFLUENCE?LIFE CYCLE COSTSThe factor „life cycle costs‟ is composed by financial sub factors and external sub factors.The bullets below present the identified sub factors that compose the factor „life cyclecost‟Financial sub factors:- Initial investment- Operating costs- Maintenance costs- Disposal costs- Change over costs- Replacement costs of elementsExternal sub factors:- Discount rate- Development energy priceThe output of the model application in chapter 6 points out that the factor „operatingcosts‟ is the most contributing factor in the life cycle costs at the three renovationalternatives. Figure 69 presents the contribution percentages of the factor „operatingcosts‟ at scenario x.2.2.2.Renovation alternativeContribution of „Operating costs‟No renovation 92%Standard renovation 79%WarmBouwen renovation 79%FIGURE 69 - CONTRIBUTION PERCENTAGES OF 'OPERATING COSTS'If the input on boundary condition „lifespan of elements/functional change rate‟ changesfrom „low lifespan/high change rate‟ into „high lifespan/low change rate‟, the life cyclecosts at the three renovation alternatives increases between 1% and 9%If the input on the sub factor „development energy prices‟ changes from „lower thanexpected‟ into „higher than expected‟, the life cycle costs at the three renovationalternatives increases. The impact is presented in figure 70.Renovation alternativeImpact of development energy priceNo renovation 43%-91%Standard renovation 34%-89%WarmBouwen renovation 34%-89%FIGURE 70 - IMPACT OF DEVELOPMENT ENERGY PRICE ON LCC84

There is a positive correlation between the performance on the main factor „energyperformance coefficient‟ and the performance on „life cycle costs‟. The correlationcoefficient is 0,69 for the situation between „no renovation‟ and „standard renovation‟.LIFE CYCLE YIELDSThe factor „life cycle yields‟ is composed by the sub factors that are listed below:- Risks- Primary returns (rent)- Secondary returns (exit yield)Hereby, the most important component with the largest contribution on this factor is thesub factor „primary returns‟.Based on the new WWS (woning waarderingstelsel) that will be implemented in theNetherlands in 2011, there is a negative correlation between the EPC and the LCY. If theEPC decreases (performance improves), the LCY increases (performance improves). Theaverage correlation coefficient between these factors is -0,42.LIFE CYCLE ENVIRONMENTAL IMPACTThe factor „life cycle environmental impact‟ is composed by several sub factors. Thebullets below present the identified sub factors.Assembly:- Materials- Processing andmanufacturing- TransportLife cycle:- Replacements- Energy useDisposal:The sub factor „energy use‟ is the most contributing aspect for the „life cycleenvironmental impact‟ of a house at the „no renovation‟ and „standard renovation‟alternative. Figure 71 presents the contribution of this aspect per renovation alternative.Renovation alternativeImpact of energy use on LCEINo renovation 67% - 79%Standard renovation 38% - 50%WarmBouwen renovation 26% - 35%FIGURE 71 - IMPACT OF ENERGY USE ON LCEIAt the „WarmBouwen renovation‟ the sub factor „assembly‟ is the most contributing factorwith impact percentages between 33% - 46%.The impact of changes in the boundary condition „lifespan of elements/functional changerate‟ on the performance on „life cycle environmental impact‟ is presented in figure 72.Renovation alternativeImpact of „lifespan elements/change rate‟No renovation 13,5% - 15,6%Standard renovation 15,9% - 19,8%WarmBouwen renovation 18,0% - 25,4%FIGURE 72 - IMPACT OF 'LIFESPAN ELEMENT/ CHANGE RATE' ON LCEIThe impact of changes in the boundary condition „lifespan of building‟ on the performanceon „life cycle environmental impact‟ is presented in figure 73.Renovation alternativeImpact of „lifespan building‟No renovation 0,4% - 1,2%Standard renovation 5,2% - 10,2%WarmBouwen renovation 0,7% - 10,7%FIGURE 73 - IMPACT OF 'LIFESPAN OF BUILDING' ON LCEI85

QUALITYThe „quality‟ is composed by several sub factors. The bullets below present the identifiedsub factors.User health:- Sound- Air quality- Thermal comfort- Visual comfortUser quality:- Technical qualityFuture value:- Future orientedfacilities- Flexibility- Experienced valueThe composition of the factor „quality‟ is static over the life cycle of a building, unlesschanges are applied. The contribution of the sub factors that compose the factor quality,is not influenced by boundary conditions.ENERGY PERFORMANCE COEFFICIENTThe „energy performance coefficient‟ is composed by several sub factors. The bulletsbelow present the identified sub factors.Technical performance:- Thermal capacity- Infiltration- TransmissionInstallation techniques:- Ventilation- Tap water- Space cooling- Space heatingThe composition of the factor „energy performance coefficient‟ is static over the life cycleof a building, unless changes are applied. The contribution of the sub factors thatcompose the factor energy performance coefficient is not influenced by boundaryconditions.BOUNDARY CONDITIONSThe „boundary conditions‟ consists of four sub factors. The bullets below present theidentified sub factors.- Scope- Reference building- Lifespan of the building- Lifespan of elements / functional change rateWARMBOUWEN SUB QUESTIONS5. WHAT ARE THE CHARACTERISTICS OF WARMBOUWEN?WarmBouwen is an innovative renovation concept which increasingly complies withsustainability aspects as comfort and health, energy, and economy compared to existingsystems for interior climate regulation and house improvement.The WarmBouwen concept is based upon the principle of accumulation instead ofinsulation and brings a building into balance with its environment; climatologic andenergetic. WarmBouwen consists of existing and proven techniques whereby thecombination of these techniques is new. The main elements of the WarmBouwen conceptare an aquifer, a heat pump, and an aquiferous package that is used for transporting andemitting heat and cold to the interior of a building, and for harvesting energy in thefacades.86

6. WHAT IS THE SUSTAINABLE PERFORMANCE OF WARMBOUWEN?The WarmBouwen renovation concept scores the best on the factors „life cycle yields‟,„life cycle environmental impact‟, „quality‟, and „energy performance coefficient‟ at alldefined scenarios. On the factor „life cycle costs‟ WarmBouwen scores better than thealternative „standard renovation‟ at all defined scenarios. WarmBouwen scores betterthan „no renovation‟ on 21 of the 27 defined scenarios.7. WHAT ARE IMPROVEMENTS FOR THE WARMBOUWEN RENOVATIONCONCEPT?The performance of the WarmBouwen concept can be improved by the followingmeasures:Changing the type of energy generationIf the electric heat pump is replaced by a gas heat pump, the performance on three mainfactors of influence is changed. The impact of this measure is summarized in the bulletsbelow:- LCC: 38% improvement- LCY: 3% deterioration- LCEI: no impact- Q: no impact- EPC: 46% deteriorationApplying solar energy systemsIf a 3,9m 2 PV-system and a 4m 2 solar heating system are applied on a WarmBouwenhouse, the performance of four main factors of influence improves. The impact of thesolar energy systems is summarized in the bullets below:- LCC: 20% improvement- LCY: 3% improvement- LCEI: 13% improvement- Q: no impact- EPC: 34% improvementReplacing the fixed internal walls by flexible internal wallsApplying flexible walls instead of fixed walls can contribute to the LCEI of a renovationconcept. It depends on the lifespan of a building and the change rate during this lifespanwhether a flexible wall system results in an improvement of the LCEI of a renovationconcept. If flexible walls are applied at scenario 3.3.1.x of this research, the „life cycleenvironmental impact‟ improves with 16%. Applying flexible walls does not significantlyinfluence to other main factors of influence.87

7.2 FURTHER RESEARCHFuture research in the field of sustainable real estate and implementation of sustainablerenovation concepts could be focused on the following subjects.Development of flexible and reusable compartments and materialsThis research points out that materials, flexibility, and reusability are aspects thatbecome more significant if the sustainable performance of a renovation conceptincreases. It is plausible that more efficient systems for interior climate control of houseswill be developed and implemented in the near future. Therefore, it is interesting toimprove the performance on the aspects materials, flexibility, and reusability also toincrease the sustainable performance of these efficient energy systems. For the conceptof WarmBouwen it would be interesting to research the possibilities to replace the currentapplied materials of the concept by materials with less environmental impact. Also, itwould be interesting to investigate the possibilities to develop flexible and demountable“WarmBouwen modules” that can be used several times in several buildings, for severalfunctions.Determine the impact of harvesting energy with the WarmBouwen conceptThe goal of the WarmBouwen concept is to harvest energy with help of the WarmBouwenpackage in the facades. In this research, the contribution of this harvesting is out of thescope. It is interesting to determine the exact result of energy harvesting with theWarmBouwen package in the facades of a building and the effect on the economicalfeasibility of the concept. This information simplifies the determination of the optimaldesign of the WarmBouwen package at a project.Extensive research on life cycle yields factorThe impact of sustainability on the exploitation of buildings is a hot issue in the currentreal estate markets around the world. Although some research is already performed onthe relation between the energy performance of real estate and the value of real estate,it is very interesting to investigate the relation between the quality, energy performance,and environmental impact on the exploitation and value of a house.Weighting factors of the modelThe model that is developed in this research consists of five main factors of influence onthe performance of a renovation concept. Also, it is stated that the weight factors thatare assigned to each main factor of influence differ per owner/stakeholder. It isinteresting to investigate the weight factors that are assigned to the identified factors ofinfluence by the different identified stakeholders of a sustainable renovation project.88

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APPENDICES93