Preparation of Articles for the Symposium Report

Design of a sustainable and affordable house concept for theNetherlandsFilique Nijenmanting,Arup B.V.,the Netherlands,filique.nijenmanting@arup.comMehmet Sinan Senel,Eindhoven Universityof Technology,the Netherlands,msinansenel@gmail.comPaul Rutten, Eindhoven University of Technology, NL, P.G.S.Rutten@bwk.tue.nlMarcel Loomans, Eindhoven University of Technology, NL, M.G.L.C.Loomans@bwk.tue.nlBart Kramer, Arup B.V., NL, bart.kramer@arup.comSummaryThe purpose of this research was to design and analyse sustainable and affordable houseconcepts suitable for the Netherlands, focusing on single family houses in terraced house typology.Sustainability is defined based on 6 value domains and an assessment method is used which isable to combine all topics of interest. In this research ‘affordable’ is defined as the average cost ofa new house within the Dutch context. Each topic is analysed based on the description of theassessment method, the performance of the current housing stock and the possibilities forimproving the performance of the house for that topic. All outcomes of the preliminary study,interviews with experts and topic analysis resulted in two conceptual design directions, the‘passive’ and the ‘active’ concept. The passive concept is designed mainly with measures which donot consume energy to perform and the active one is designed mainly with energy systems(technology, hardware) based solutions. These concepts are assessed and compared in order toestimate the performance and robustness of the solutions. The recommendations for improvementthat are concluded from this analysis are implemented in a ‘hybrid’ concept. The conclusions of thestudy include recommendations for solutions for sustainable and affordable house concepts in theNetherlands. It is shown that ‘passive’ means, as defined in this study, are more favourable than(small scale) technology based solutions in achieving the sustainability goals within affordableconstraints for an individual dwelling. Sustainable energy technologies become moreadvantageous both economically and environmentally in large scale applications.Keywords: Sustainability, affordability, Netherlands, active, passive, BREEAM-NL, eQUEST, singlefamily terraced house1. IntroductionGrowing concerns about impending global warming and scarcity of energy sources lead to effortsto use different energy sources and use sources more efficiently. Since the energy consumption ofthe building sector constitutes about 40% of the fossil fuel primary energy demand [1], buildingshave become one of the focus points for these efforts. Introduction of sustainable energytechnologies and reducing energy demands are at the heart of the endeavour to improve theenvironmental performance of the buildings.Although the view on sustainable development has become broader in some fields, the regulations

in the Netherlands still focus on energy reduction in buildings, by use of an energy performancecoefficient (EPC).To describe the significance of broadening the perspective of sustainability in the Netherlands, theDutch governmental policy and its studied basis have been taken as a starting point. Sustainabilitypolicies are constructed from the National Environmental Policy Plans [2] (in Dutch: NationaalMilieubeleid Plan = NMP), of which the latest version is NEPP 4, dated 2001, which considers astrategy until 2030. This report gives an overview of the governmental policies to mitigate theenvironmental burdens on future generations. The plan concludes with the positive effect ofenvironmental policy, because it resulted in the dissolving or manageability of environmentalproblems. It discusses 7 environmental problems which show that energy reduction is not the onlytopic to which attention should be given. It also considers the depletion of resources, generalhealth, safety and quality of life.Since the amount of energy, water and materials which is used by residential buildings issignificant, it is important to improve the performance of new build houses in this sector in order toreach the goals which were set in NEPP 4. The research objective of this study is therefore todevelop an appropriate example for the design of a new-build house for the Netherlands, whichcan be affordable for the target group, which will be specified below, and complies with thegovernmental aims to reduce the impact of the discussed environmental problems.2. Preliminary study and methodology2.1 Preliminary studyA preliminary study [3] addressed the assessment of sustainable housing in 6 case studies. Thenumber and type of case studies found showed a narrow approach to sustainable building design:solutions are mainly found for experimental projects instead of general concepts which areapplicable at a large scale. The six value domains which are used to define sustainability asdescribed by Rutten [4] were not addressed or were addressed with a limited perspective. For thebasic value, which is determined from a building’s relationship with individual occupants’ well-being,the attention was given low for acoustics, spatial design and internal air quality. The economicvalue of the case studies was almost ignored, except for benefits from energy consumptionreduction. The latter is the most addressed topic in the case studies. Other aspects of theecological value, which considers the relationship of the building with the global environment, weregiven medium or very low attention (building materials, land use and flora/fauna). Strategies toimprove the future performance (strategic value) of the case studies were hardly found.Manageability and ease of operation and maintenance were sometimes enhanced by user guides,but extra focus could be given to the design of simple systems with low maintenance to increasefunctional value. Local values, which are based on special conditions that are unique to a particularplace, were generally included in the designs. Therefore the focus on sustainability lacked attentiontowards the applicability and feasibility of the projects thereby not giving accessibility to a largeshare of the population.2.2 Methodology of the studyThe main challenge of this study was to find a solution for the design of an affordable andsustainable house for the Netherlands, which is defined in the main research question as:What is the optimum combination of design strategies and measures to achieve high basic,environmental and economic value in the design of a ‘sustainable’ and ‘affordable’ single familyhouse in the Netherlands?The main research question is broad and directs the answer of it into design decisions based onreasoned arguments. The conclusions from the preliminary study are used as inputs for specificpoints of interest which are defined according to the framework of BREEAM-NL [5].Due to the large number of parameters to be included in the study, the number of concepts is kept

to a limited number. The concepts are based on two themes:• Passive design, where the (investment) focus is predominantly on passive systems: they arecharacterised by their direct interaction between the building fabric and the environment. They donot produce energy and do not need any mechanical devices or significant mechanical energy inorder to operate.• Active design, where the (investment) focus is predominantly on active systems: they aredesigned to utilise the environment to avoid or meet a significant proportion of the demand. Thesesystems either produce energy, or they operate in conjunction with some mechanical devices toutilise renewable energy to provide heating/cooling.The concepts are compared to a reference house that represents the current Dutch buildingpractice. The comparison is based on the BREEAM-NL framework. From the conclusions of thecomparison, an optimised version, which integrates both design strategies, is designed andassessed according to all topics of interest.2.2.1 Boundary conditionsThe Netherlands has been chosen as the location for the design. Though acknowledging currentlocal differences, the boundary conditions are defined for the Netherlands as a whole, therebyaccounting for the climate, the national building regulations and selling price.The demand for houses in the Netherlands is projected to increase over the coming years (withabout 50,000 houses to be built each year between 2006 and 2020). This demand could be fulfilledby new build homes or renovations; the research focus is on the former. The highest demand is forsingle family houses and owner-occupied property in the low-price cost range. Following Socrates2006 [6], the specifications for the applied reference house are summarized in Table 1. A referencerow-house from SenterNovem [7] (with balanced ventilation and heat recovery; EPC 0.74) waschosen to represent the current stock and building practice.Table 1: Specifications of the reference house type for this research. Source: summary of detailsfrom the Socrates 2006 research by Poulus and Heida [6].TopicSpecificationOwnershipOwner-occupied propertyHouse typeSingle family houseBuilding typePrice range (selling price)Living environmentAmount of rooms 4Surface area of house 126 m 2Surface area of living room 35 m 2Price per m 2Terraced houseLow-price:Below 200,000 euro (2006)Below 215,000 euro (current level 2010)Rural: Villages Centre1,540 euro% of homes accepted in terraced configuration 59%2.2.2 Topics of interestThe studied topics of interest are derived from the preliminary study [3], the requirements as foundin the Dutch policy program and the definition of sustainability as given by the six value domains.The topics and the level of depth in this study are presented in Table 2.

Table 2: Specifications of aimed house type and defined topics of interest for this studyOverall objectivesSustainable design Affordable design Integral designBoundary conditions (SenterNovem reference house)Region:the NetherlandsHouse type: single family row-house,balanced ventilation with heatrecovery, 130 m 2 user areaPrice range: Low selling price(< €219,400), owneroccupied propertySpecific points of interestGeneral topic Specific topic Level of depth for this studyThermal comfortHighIndoor air qualityHighHigh basic value:Visual comfortHighHealth, comfort, ease of useAcoustic comfortHighand safety.Domotica*MediumSafety - accessibilityLowCO 2 emission during useHighHigh ecological value:Embodied energyMediumCO 2 emission by use orCarbon footprint of residents Mediumconstruction, waterWater consumptionMediumconsumption, wastemanagement.Water recyclingMediumHousehold wasteLowHigh economic value: Building costsMediumAffordabilityReturn of investmentMediumHigh strategic value: Technical flexibilityMediumFlexibilityUseability of different usersMediumHigh functional value: Use of proven technologiesLowOperation, maintenance Choice of low maintenance solutions LowHigh local value:Use of local know-howLowApplicabilityCompatibility with local regulation Medium* Dutch term for home automation2.2.3 BREEAM-NL v1.2 (Residential)Two studies by DHV [8] and by Dobbelsteen [9] conclude with a positive result for the use ofBREEAM in the Netherlands, if a broad spectrum of topics needs to be handled. In 2008, theDutch Green Building Council (DGBC) started translation of BREEAM to BREEAM-NL. SinceMarch 2010, a beta version for residential buildings is published [5]. When ‘BREEAM-NL’ ismentioned, it refers to this residential version. The assessment of a building is based on a list ofcredits which complies with the Dutch law and regulation, practice guidelines and building practice.All credits are divided into the following categories, which are weighted by pre-determinedimportance: management, health and comfort, energy, transport, water, materials, waste, land use& ecology and pollution.One of the reasons to choose BREEAM-NL as an assessment method is its clear categorisation oftopics and criteria. From this assessment method, applicable topics for the project have beenchosen. Topics are left out for different reasons: the phase of design; (conceptual, not being built)the lack of exact location details; the scope in objectives; and expertise of the design team. Thetotal amount of criteria reduces therefore from 39 to 13 and the number of maximum achievablecredits reduces from 89 to 37. Not all topics of interest could be expressed in BREEAM-NL credits.Some of them are implicitly taken into account through the use of BREEAM-NL as a guideline(functional value and applicability); for others a specific assessment method was developed (witheconomic value expressed in payback time and investment per BREEAM-NL credit). For theassessment of performance criteria within the framework of BREEAM-NL separate tools have beenapplied for energy demand and thermal performance (eQUEST), daylight (ADF), materials(Greencalc), costs (annuity model), and specifications from drawings or product suppliers.

3. Results3.1 Topic analysis and designA short description of the results of the analysis for each topic identified is provided below.3.1.1 Thermal comfortThermal comfort is assessed according to BREEAM-NL (HEA10) by calculating the amount ofoverheating hours (max. 300) over the Predicted Mean Vote (PMV) value of +0.5. This value indicatesfor example a living room with a temperature of 26.5 °C in summer, which could be workedout on an hourly basis by using dynamic building simulation. Assuming current outdoor temperatures,for about 93% of the year heating would be necessary and around 3% of hours would resultin overheating. The passive means of satisfying the heating demands include enhancement ofbuilding skin properties in terms of insulation and air tightness values, but could also include thepositioning of thermal zones. Prevention of overheating could be achieved by changing windowtypes and solar shading. The choices to be made with this are numerous and are partly based onthe economic analysis of several measures under the categories of ‘economic value’ and ‘spatialcomfort’ and by the definition of the passive and active concept.Active systems which could assist in achieving these demands were studied. The most advantageoustype is the floor heating option, which has a lower energy consumption, high thermal comfortand indoor air quality when compared to high temperature heating. The disadvantage of slowresponse could be solved by reducing the dynamics of the external loads for example by high insulationvalues or outside shading devices.3.1.2 Indoor air qualityThe quality of indoor air is assessed by BREEAM-NL (HEA8) which defines the demands accordingto a maximum level of CO 2 concentration. The minimum ventilation flows for houses whichcomply with this can be found in the Dutch Building Decree (e.g. 0.9 dm 3 /s/m 2 for user areas). Theflows should be assured with the help of mechanical exhaust. The limits for infiltration are prescribedin the Building Decree and are applied for the active concept. For the passive concept airtightness is improved in order to limit uncontrolled losses. To comply with the regulations and thedescription of passive design, natural inlet and mechanical exhaust is applied for the passive conceptand a balanced ventilation system with heat recovery is applied in the active concept.3.1.3 Visual comfortVisual comfort is assessed based on the amount of available daylight in BREEAM-NL (HEA1) usingthe BRE Average Daylight Formula. This takes into account window area, partitions area, windowtransmission, the visible sky angle and the average reflection factor. The demanded daylightfactor of 2% in at least 80% of all user areas should give the house a day lit appearance and a lowamount of supplementary electric lighting would be needed. Fixed assumptions were made fordistance of obstructions and reflection factors.In order to improve the house energy performance, improvements were assumed in artificial lightingtypes for both the active and passive concepts. Since the reference house does not complywith the 80% area with 2% ADF demand (results in 71%), both the passive and active conceptwere given increased (or different placed) window sizes.3.1.4 Acoustic comfortDemands for acoustic comfort are given in BREEAM-NL (HEA13), which include the noise insulationvalues of external, internal and adjacent skin partitions. The characteristic services sound levelis for example limited to 30 dB(A). A short description of building parts showed the achievement ofnoise insulation characteristics for the building skin. Details of connections were deducted from the

design guide in NPR 5070 and 5086 for all concepts. Assessment on this topic was based on thisgeneral description, combined with the specifications from product suppliers for the noise productionby building services.3.1.5 Spatial comfortThe analysis of spatial comfort combines the assessment of three BREEAM-NL topics (HEA14,HEA15 and HEA16): private outdoor space, flexibility and accessibility. The demands are given bymeans of minimum areas, widths and specifications of expandability or changeability of structure.The accessibility of the reference house was assessed and concluded not to be accessible for disabledpeople. A suggestion of changed spatial planning for the ground floor was made in order toimprove the future use by elderly or disabled: a ground floor toilet plus storage room can be combinedinto a bathroom. Expandability of the reference house was concluded to be possible in thevertical direction, with a light-weight structure on top. The adapted spatial planning for accessibilitywas applied in both the passive and active concepts.3.1.6 CO 2 emissionsSince this topic is weighted highly in BREEAM-NL (ENE1: 19%) this was given a high level of attention.eQUEST was used to simulate the reference house and several concepts to assess theenergy performance of the chosen measures.The assessment of CO 2 emissions is based on fossil fuel primary energy use during the operationperiod. The amount of reduction compared to the regulated value is expressed in credit points. Theanalysis of CO 2 emissions focused on the available sources in the Netherlands and the possiblesystems that may be applied. It resulted in advice to use solar energy for both heat and electricitygeneration (with a roof inclination of between 30 and 40°). The small scale wind turbines are notrecommended due to their poor performance resulting from the large variation in available windresource. Ground source technologies are advised, since the ground typology in most parts of theNetherlands has a reasonable thermal capacity. Biomass based energy generation is not recommendeddue to the reason that the supply and storage of wood pellets, which is the only feasiblesource for small scale applications, is inefficient for a single family house.Conclusions from the system analysis are to use a high efficiency boiler (as with the referencehouse) for the passive concept and a ground source (water-water) heat pump for the active concept.Solar thermal panels are advised for supply of domestic hot water (DHW) and are combinedwith the boiler for the passive concept and the heat pump for the active concept.3.1.7 User behaviourAlthough user behaviour is not explicitly specified by the BREEAM-NL assessment, the result ofchanges in the concept on this topic will be expressed in end energy use and are therefore takeninto account under CO 2 emissions. Based on literature research from ECN and TNO [10], it couldbe concluded that feedback can have a positive effect on reduction of energy consumption. Combinedwith the assumed energy pattern for a large group of households, for the concepts someassumptions could be made. These include analogue thermostats, room temperatures of 20°C,windows closed while heating, stand-by killers on electrical equipment and energy-efficient appliances.Hot water schedules are assumed not to be influenced.3.1.8 Building materialsThe effect of building materials on the environment is assessed in BREEAM-NL (MAT1) by use ofthe shadow price. This price is calculated from the impact of nine environmental aspects of thebuilding materials (greenhouse effect, damage to ozone layer, humane-, aquatic-, and terrestrialtoxicity, photochemical oxidants, acidification and eutrophication).

3.2 Concepts and comparisonThe results from the analyses of the topics have been compiled and translated into the two designconcepts. The main line of the concepts was defined by the passive/active definitions and therecommendations from each topic analysis. These two concepts and the reference house arepresented in Table 3.Table 3: Reference house and the two developed concepts.Reference house Passive concept Active conceptR c values skin: 3-4 m 2 K/WU window : 1.8 W/m 2 KAir tightness: 0.62 dm 3 /s/m 2Balanced ventilationHeat recovery on vent. airGas fired boiler, combiHigh temp. radiatorsNo water saving optionsArtificial lighting 50 lm/WR c values skin: 7-8 m 2 K/WU window : 1.3 W/m2KAir tightness: 0.15 dm 3 /s/m 2Mechanical exhaust vent.Solar thermal collectors 6 m 2Gas fired boiler, combiLow temp. floor heatingLow flow tap, toilet, showerArtificial lighting 25 lm/WR c values skin: 3-4 m 2 K/WU window : 1.8 W/m 2 KAir tightness: 0.62 dm 3 /s/m 2Balanced vent. + heatrecoverySolar thermal collectors 6 m 2Vertical ground source heatpumpLow temp. floor heatingLow flow tap, toilet, showerArtificial lighting 25 lm/WThermal comfort was assured in all concepts, as well as indoor air quality (although assured bydifferent systems). The difference could mainly be found in annual energy use for heating andelectricity demands. The heat demand did not differ much between the concepts, since the gainfrom increased insulation values of the passive concept was lost through the ventilation principle(natural ventilation). The ground source heat pump affected significantly the fossil fuel primaryenergy use for space heating, but the investment costs could not be paid back by this reductiondue to the low energy prices assumed. By means of the solar thermal panels, fossil fuel primaryenergy use for domestic hot water could be reduced by 10-12 GJ/year. These comparisons areillustrated in Figure 1.Daylight design was improved for both concepts, and the demand is now met. Combined withenergy efficient lighting, this resulted in up to 47% reduction in electricity consumption for artificiallighting. Acoustic comfort was assured by using the building details as prescribed, combined withwell designed ventilation systems. Accessibility was assured by the adapted space plan, whichalso resulted in a storage space for household waste. The water use of the concepts was reducedto 62 m 3 per year by the presented measures.As shown in Figure 1, both the passive and active concepts appeared to be more expensive thanthe reference, and both of the concepts were found to have a higher selling price than thepredetermined affordability limit of € 219,400. The passive concept was found to be 10% moreexpensive than the reference and, despite the achieved energy reduction, is not cost-effectivewithin 30 years of mortgage, with the assumed energy prices [12][13]. A sensitivity analysis of theenergy price showed that feasibility for the passive concept would be attained if the energy price

increase per year were to exceed 7.8%. By the same analysis it is shown that the active conceptwould only be feasible if it were designed with PV cells to cover electricity consumption in a yearand the annual energy price increase were to exceed 10%. Both results are illustrated in Figure 2.Fig. 1 Fossil fuel primary energy consumption and estimated costs for the two concepts and thereference house.Fig. 2 Sensitivity of the two concepts, as is and with additional design options (passive + heatrecovery; active + PV), on energy price change, data points indicate feasibility of passive resp.active concept at certain energy price increase.

The small difference as a result of difference in building materials and the difference in use of fossilfuel primary energy was reflected in the BREEAM-NL weighted percentage of credit points. Theselling price per percentage was lower for the active (3713€) and the passive (3733€) conceptsthan for the reference house (6203€). On the other hand, the additional investment cost for fossilfuel primary energy reduction compared to the reference house is lower for the passive concept(569.8€/GJ) than the active concept (908 €/GJ).3.3 Hybrid ConceptSince the passive concept was favourable in terms of the sustainability versus affordability criterion,this concept was chosen for further improvement. In order to achieve a lower heating energydemand than the passive concept, balanced ventilation with heat recovery is implemented. To keepthe investment costs low, the gas fired boiler is retained in the design. This results in higherinvestment costs (exceeding boundaries) due to the ventilation system, but a reduction in heatingenergy. The annual energy costs increased compared to the passive concept, due to a differentmix of electricity (increased for fans) and natural gas (reduction). Therefore, the fossil fuel primaryenergy use could be lowered to the active concept levels while keeping the investment costs closeto the passive concept. As a result of this, the selling price per BREEAM-NL weighted percentageof credit points criterion is the lowest for the hybrid concept (€3482) as compared to the twoconcepts individually. The investment cost per decreased GJ of fossil fuel primary energy is closeto the passive concept levels. However, the selling price is still higher than the predeterminedaffordability limit and the investment is not paid back with the estimated energy price increase[12][13].Figure 3 illustrates the fossil fuel primary energy reduction and the slight increase in selling pricecompared to the passive concept. Further reductions for the fossil fuel primary energy use can beachieved by replacing the gas fired boiler with sustainable energy technologies. For example,geothermal energy might be a promising replacement for the fossil fuel sources.Fig. 3 Fossil fuel primary energy consumption and estimated costs for the three concepts andthe reference house

Although district heating is claimed to be a cost effective alternative to a gas fired boiler thatdecreases the fossil fuel primary energy consumption significantly, investigation with current pricesshows the economically favourable position of the gas fired boiler as shown in Figure 4. As can beseen, the hybrid concept with gas fired boiler and the passive concept have similar sensitivity toenergy price changes, although the break-even point for the hybrid concept is higher due to theinvestment in mechanical ventilation with heat recovery. The extra investment for the ventilationsystem is compensated for if the annual energy price change increases to 8.8%.Fig. 4 Sensitivity of concepts on energy price change, Data points indicate feasibility of passiveresp. active concepts at certain energy price increase4. Discussion and Conclusions‘Integral design’ is a complex process and difficult to prescribe in a stepwise approach. In order toanswer the main research question an approach which starts with a detailed analysis of bothdemand and supply aspects of the focus areas was implemented. The outcomes of the analysishave been evaluated to make design decisions, in terms of both ‘passive’ and ‘active’ measures asdefined previously. The design decisions were made to propose two concepts, the ‘active’ and‘passive’ concept, in order to find the optimum combination of measures. The resulting conceptsare assessed in terms of their environmental performance and financial consequences.From the two concepts, the best in terms of basic, environmental and economic values waschosen to be the baseline for the hybrid design which is intended to be the optimum concept.Although both concepts achieved around 30 GJ per year fossil fuel primary energy saving, thedetailed calculations and dynamic simulations showed that the passive concept performed the bestin terms of energy consumption and financial measures. The calculated selling price of the passiveconcept exceeds the predetermined affordability limit but it is more favourable than the activeconcept in terms of investment cost per fossil fuel primary energy saving figure. This shows thatthe passive measures are more viable than the active measures in small scale applications. Thehybrid concept is designed based on the passive concept with the addition of the balancedventilation with heat recovery.The resulting hybrid design exceeds the selling price boundary, but requires a much lower heatingpower demand and reduces the fossil fuel primary energy use and CO 2 emissions. Due to a

different mixture of gas- and electricity use, the annual expenditure on energy appeared to behigher than with the passive concept. It should be noted that the use of electricity instead of naturalgas could be more favourable in the sense that the electricity could be generated both on-site andat large scale in a sustainable way while natural gas is one of the fossil fuels which have limitedavailability. Also the selling price per weighted BREEAM-NL percentage is lower than the otherconcepts, although the difference is not significant.The economically unfeasible position of the ‘active’ solutions at small scale, based on the energyprice predictions in this study, demonstrate the requirement for large scale solutions for bothfinancial and environmental benefits. Depending on the type of generation, heat energy generationat large scale promises high fossil fuel primary energy and CO 2 emissions savings of up to 80%.Therefore, energy can be supplied to the households in a more sustainable way while keeping thefinancial conditions at comparable levels to conventional systems. However, the economicfeasibility of large scale systems for end-users is highly dependent on the yearly costs reflected ontheir yearly bills and investment costs. Considering current price levels these systems are morecostly than gas fired heating systems per house (taken into account both investment andoperational costs).As a result of all analysis, it became evident that the measures to achieve a higher level ofsustainability are more costly than with current practice. This results either from the larger quantityof materials used, the complexity of the systems or the higher attention for detail which demandsmore labour during construction. Therefore end-users can achieve reduction in energy demand butthe Government and the local authorities should take measures to meet the remainder in a moresustainable and economically feasible way.5. AcknowledgementsThe authors would like to thank Jeroen de Wilde and Vincent van Sabben (IGG) for their valuableinput with respect to the building costs and Frank Donkers and Léon van Maurik from Kingspan fortheir practical contribution.6. References[1] US Department of Energy, Annual Energy Review 2008, 2008[2] VROM (Dutch Ministry of Housing, Spatial Planning and the Environment), NationaalMilieubeleidsplan 4 (NMP4) ‘Een wereld en een wil: werken aan duurzaamheid’, nota, articlecode 1076, The Hague, 2001[3] NIJENMANTING F.C. and SENEL M.S., Assessment of sustainable housing projects, facultyArchitecture, Building and Planning, faculty Mechanical Engineering, Eindhoven University ofTechnology, Eindhoven, master projects, 2010[4] RUTTEN P.G.S., Strategisch bouwen, Eindhoven University of Technology, Eindhoven,inaugural speech, 1996[5] BREEAM-NL, Keurmerk voor duurzame vastgoedobjecten, v1.2 bèta BeoordelingsrichtlijnNieuwbouw, Dutch Green Building Council, Rotterdam, 2010[6] POULUS C. and HEIDA H.R., Woningmarktverkenningen, Socrates 2006, ABF Research,Delft, 2006[7] SENTERNOVEM, Referentiewoningen nieuwbouw, Senternovem, Sittard, 2007[8] CLOCQUET R., BOONSTRA C. and JOOSTEN L. Instrumenten Beoordeling en PromotieDuurzame Kantoren, DHV B.V., published under authority of SenterNovem, 2008[9] DOBBELSTEEN van den A.A.J.F Modelvergelijking voor de Nederlandse Green BuildingTool, TU Delft, faculty of Architecture, Climate Design & Sustainability, Delft, 2008[10] PAAUW J. and ROOSSIEN B. Energy pattern generator- understanding the effect of userbehaviour on energy systems, ECN, Petten, Netherlands, 2009[11] IGG cost consultants. Personal communication, 2010[12] ECN, Referentieramingen energie en emissies 2010-2020, ECN, Petten, Netherlands, 2010[13] BOLLEN J., MANDERS T. and MULDER M., Four futures for energy markets and climatechange, CPB Netherlands Bureau for Economic Policy Analysis, The Hague, 2004