Nous passons la majeure partie de notre vie dans des bâtiments. Ces derniers ont été construits, pour la plupart, avant les chocs pétroliers de 1974 et 1979, et offrent une performance énergétique médiocre ainsi que des conditions de confort (thermique, acoustique, éclairement naturel) largement améliorables. En France, avec 32 millions de logements et un taux de renouvellement annuel du parc existant inférieur à 1 %, la rénovation énergétique des logements devient une nécessité. Cela, autant pour des raisons politiques (indépendances énergétiques), économiques (relance des emplois de la construction, valorisation du patrimoine), sociales (bien-être des occupants, lutte contre la précarité), qu'environnementales (diminutions des émissions des gaz à effet de serre). Ce travail de thèse vise à proposer des connaissances ainsi qu'une méthodologie afin de contribuer à l'aide à la décision pour la prescription de scénarios d'amélioration énergétique efficaces des maisons individuelles construites durant la période 1945-1974. Trois problématiques sont mises en avant dans cette recherche. 1) l'intégration de l'approche globale (systémique et multicritère) de la rénovation afin d'éviter des contre-performances collatérales dues à des mauvais choix ; 2) l'aide à la formalisation des préférences des propriétaires-occupants (notre maîtrise d'ouvrage) dans un format interprétable par des outils d'analyses multicritères ; 3) l'intégration des incertitudes liées à la caractérisation des bâtiments existants dans le processus d'élaboration des scénarios et d'aide à la décision. À travers une description systémique des bâtiments et une évaluation multicritères des performances des actions d'amélioration retenues, nous proposons une méthodologie innovante, constituée de 6 sous-modèles techniques modulables et interchangeables, qui vise à automatiser le processus de construction, d'évaluation et de hiérarchisation performantielle de scénarios de rénovation. Le cœur de notre méthodologie est basé sur la formalisation de l'expertise métier des spécialistes du bâtiment dans deux de nos 6 sous-modèles. Le premier est une matrice d'influence permettant de passer des enjeux de rénovation les plus courants (équivalent aux préférences exprimées par la maîtrise d'ouvrage) en profil de poids relatifs et profil de niveaux-cibles de performance sur les indicateurs modélisés. Le second, est un outil d'inférence probabiliste (utilisant la technologie des réseaux bayésiens) permettant à la fois d'optimiser les assemblages d'actions d'amélioration (programmation par contraintes successives) et de réaliser une évaluation multicritère de ces assemblages (par l'usage de fonctions d'agrégation de performances locales). Un sixième et dernier sous-modèle utilise les méthodes de surclassement ELECTRE pour trier et classer les alternatives de rénovation préalablement générées par ordre de préférence. Notre méthodologie offre enfin la possibilité de laisser l'utilisateur tester ses propres scénarios d'amélioration énergétique afin d'analyser leurs performances multicritères et leur compatibilité avec les caractéristiques de l'existant capitalisées lors du diagnostic technique d'une opération. La méthodologie développée se veut pédagogique et transposable dans un prototype d'outil informatique fonctionnel. Une première version a été développée et utilisée pour appliquer notre processus d'aide à la décision à un cas réel de maison individuelle à rénover. Les premiers résultats obtenus sont cohérents et permettent de valider la démarche. Néanmoins, il faut garder à l'esprit que comme tout modèle utilisant des connaissances expertes, sa robustesse et la limite de validité de son périmètre d'application dépendent de la qualité du savoir métier capitalisé. / We spend most of our lives in buildings. These were built mostly before the oil shocks of 1974 and 1979 and offer both poor energy performances and improvable comfort conditions (thermal, acoustic, natural lighting). In France, with 32 million units and an annual turnover of less than 1% of the existing building stock, the energy renovation of housing becomes a necessity. This, as much for political ends (energy dependence), economic reasons (revival of construction jobs, real-estate valorisation), social reasons (wellbeing of occupants), as environmental reasons (reduction of greenhouse gas emissions). This thesis aims to provide knowledge and a methodology to contribute to the decision support for prescribing efficient energy renovation scenarios of houses built during the 1945-1974 period. Three issues are highlighted in this research work: 1) the integration of an holistic approach of renovation process (systemic and multi-criteria) to avoid not foreseen collateral effects due to bad choices; 2) help formalize the preferences of decision-takers (homeowners) in a format interpretable by multi-criteria analysis tools; 3) integration of uncertainties related to the characterization of existing buildings in the process of scenarios generation and decision support. Through a systemic description of buildings and a multi-criteria performance assessment of formerly identified renovation actions, we propose an innovative methodology, consisted of 6 modular and interchangeable technical sub-models, which aims to automate the generation, assessment, optimization and performance-based ranking of renovation scenarios. The heart of the methodology is based on the formalization of renovation knowledge from construction specialists in two of our six sub-models. The first one is an influence matrix that we use to translate most common renovation goals (equivalent to the wishes expressed by homeowners) into a profile of relative weights and a profile of targeted-levels of performance on indicators modelled. The second one is a probabilistic inference tool (using the technology of bayesian networks) to both optimize assemblies of renovation actions (programming by successive constraints) and achieve multi-criteria evaluation of these assemblies (by the use of aggregation functions of local performances). A sixth and final sub-model uses the ELECTRE outranking methods to sort and classify, by preference order, renovation scenarios previously generated. At last, our methodology provides the ability to let users test their own energy renovation scenarios in order to analyze their multi-criteria performances and compatibility with the characteristics of the existing capitalized during the technical diagnosis of their building. The methodology proposed is intended to be educational and transposable into a functional computer system prototype. A first version was developed and used to apply our decision process to a real case of individual house to renovate. First results obtained are consistent and allow validating the approach. However, keep in mind that like any model using expert knowledge, robustness and validity limit of its scope of application depend on the quality of knowledge work capitalized.

The UK’s housing stock is among the oldest and least efficient in Europe. 85% of the UK’s existing homes will still be standing and in use in 2050. Improving the energy efficiency of UK housing stock is an essential requirement in order for the UK to meet its 2008 Climate Change Act obligations. Energy efficiency in buildings is the focus of European (EU) policies with the intention of creating a low-carbon economy by 2020. Reducing energy consumption in existing buildings is essential to achieving this. Government policies are the primary mechanism for lowering energy consumption through changing consumer behaviour, promoting low carbon technology and energy efficient renovations of old building stock.The objective of this thesis is to investigate the effectiveness of UK policies at addressing factors affecting consumer decisions to carry out energy efficient renovations. This is with the intention of determining if UK policies are effectively contributing to the government’s long term climate change commitments.Using a theory developed by Parker (2000) as a conceptual framing of policy compliance, this study conducts interviews with consumers in order to analyse their awareness, understanding and perception of UK energy efficiency policies. Therefore, it can be determined how effective policies are at affecting consumer decisions to carry out energy efficient renovations.The thesis informs that consumers are motivated and willing to comply with policies but there are several key barriers preventing them from complying with these policies and therefore adopting energy efficient renovations. Policies are deemed to be somewhat ineffective at affecting consumer decisions to carry out energy efficient renovations.

Cette thèse contribue à rendre le marché de la rénovation énergétique durable et autonome. L’objectif est de contribuer à quantifier le risque de non atteinte de la performance énergétique après rénovation. Tout d’abord, nous analysons les facteurs psychologiques des ménages à prendre en compte pour améliorer les modèles de prédictions de consommation d’énergie. Via le programme Je rénove BBC, nous mettons en évidence quatre biais cognitifs impactant l’écart de la consommation d’énergie réelle et prédite. Puis, nous étudions les structures de contrats les plus appropriés pour améliorer le déroulement des chantiers, incitant les artisans à mieux travailler. D’une part, nous déterminons des contrats pour un Agent devant effectuer deux tâches et sous-estimant l’impact de l’une d’entre elles sur la performance du bâtiment. D’autre part, nous testons des incitations individuelles et collectives sur la capacité de plusieurs artisans à se coordonner selon leur formation initiale (DORéMI, …). / This thesis aims at contributing to make the energy renovation market long-lasting and self-sustaining. To achieve this, our objective is to quantify the risk of not achieving energy performance after renovation. First, we analyze households’ psychological factors that should be considered to improve energy consumption prediction models. Drawing on the Je rénove BBC program, we highlight four cognitive biases that negatively impact the difference between actual and predicted energy consumption. We then study the most appropriate contract structures improving the flow and quality of renovation projects, encouraging craftsmen to work better. On one hand, we determine optimal contracts for an Agent who has to perform two tasks and underestimates the impact of one of them on the building's performance. On the other hand, we test individual-based and group-based incentives on the ability of several real Agents (craftsmen) to coordinate, according to their initial training (DORéMI, …).

Several climate and energy goals have been set in the European Union, one of them being to increase energy efficiency. In Sweden, a large potential for increased energy efficiency lies in the residential and service sectors, which account for about 40% of total energy use. A large share of buildings in Sweden were built in the Million Homes Program in the 1960s and ’70s. These buildings are now in need of renovation, which enables renovation with the ambition of reducing energy use.  In this thesis, the purpose is to develop an energy signature method, a bottom-up statistical method. This method has been validated using a building energy simulation software called IDA ICE, for two kinds of multifamily buildings from the Million Homes Program. The energy signature method has then been applied to a district located in Gävle, Sweden, containing more than 90 multifamily buildings with similar construction. In addition to characterizing current thermal performance of the buildings, the energy signature method is further developed so that potential for energy renovation of the district can be simulated. Simulated energy renovation is developed to comply with building energy use requirements, according to the most recent Swedish building regulations.  Both on building and district level, sensitivity analysis is performed. In both cases the energy signature method is insensitive to changes in internal heat gains and indoor temperature. To investigate the effects of simulated renovation on a local district heating system, results are visualized in a duration diagram, where energy use reduction in different load periods is displayed. Thus, it is demonstrated how the energy signature method can be used as a rapid way of simulating energy renovation on district level and with readily available data. / EU har beslutat om flera klimat- och energimål, bland annat att energi ska användas mer effektivt. I Sverige finns en stor potential för ökad energieffektivitet i bostads- och servicesektorn, som står för cirka 40 % av den totala energianvändningen. En stor av del Sveriges byggnadsbestånd består av miljonprogramsbyggnader från 1960- och 1970-talen. Dessa byggnader är i behov av renovering, vilket möjliggör ytterligare renovering med syfte att sänka energianvändningen. Syftet med denna studie är att utveckla en energisignaturmetod, en ”bottom-up” statistisk metod. Metoden har validerats med byggnadsenergisimuleringsprogrammet, IDA ICE, för två typer av flerbostadshus från miljonprogrammet. Energisignaturmetoden har sedan applicerats på ett distrikt i Gävle som innehåller fler än 90 flerbostadshus med liknande konstruktion. Förutom att karakterisera byggnadernas nuvarande termiska prestanda, vidareutvecklas energisignaturmetoden så att även energirenovering kan simuleras. Denna metod utvecklas för att uppfylla Boverkets krav på byggnaders energianvändning, enligt gällande svenska byggnadsreglerna.  Känslighetsanalys utförs både på byggnads- och distriktsnivå. I båda fallen visar sig energisignaturmetoden vara okänslig för förändringar i intern värmegenerering och inomhustemperatur. Effekterna av den simulerade renoveringen presenteras i ett varaktighetsdiagram, som visar de möjliga effekterna på ett lokalt fjärrvärmesystem. På detta sätt demonstreras hur energisignaturmetoden kan användas för att snabbt simulera energirenovering på distriktsnivå och med lättillgänglig data.

Large share of Swedish building stock were built during 1940-1980 when people were not fully aware of the energy efficiency concept. Majority of the buildings that made energy declaration are in energy class E-G, which are considered as high energy consumption buildings with low energy performance, and only few buildings meet the Swedish requirements for near zero energy buildings which are in energy class A-C. The energy renovation rate of the existing buildings is low and more needs to be done to make the Swedish building stock energy and resource efficient. In this thesis the potential of energy efficiency improvement is investigated for an old multi family house built during the Million program in Sweden. Passive energy renovation measures on the demand-side along with active energy renovation measures on the supply-side were investigated together with their combinations resulting in eight different cases. The investigated demand-side refurbishments are additional attic floor insulation and replacement of windows with insulated glass windows while the supply-side refurbishments are rooftop PV installation and conversion to water-based heating system with GSHP. The results of this study show that combination of all four energy efficiency measures has the highest energy-saving potential and yields the highest NPV compared to the other cases for an assumed real discount rate of 3% and grid purchase price of 1.60 SEK/kWh, while requiringthe highest CAPEX. On the other hand, GSHP with water-based heating system requires two times lower CAPEX, however, has high energy-saving potential and yields high NPV. / En stor del av Sveriges byggnadsbestånd byggdes under 1940-1980, då folk inte var fullt medvetna om energieffektiviseringskonceptet. Större delen av byggnaderna som har upprättat energideklaration är i energiklass E-G vilket anses vara byggnader med hög energibrukning med låg energiprestanda och endast ett fåtal byggnader uppfyller de svenska kraven som ställs för nära noll energi byggnader som är i energiklass A-C. Energirenoveringstakten i de befintliga byggnaderna är låg och mer behöver göras för att göra Sveriges byggnadsbestånd energi- och resurseffektivt. I detta examensarbete undersöks potentialen för energieffektivisering i ett äldre flerfamiljshus som byggdes under Miljonprogrammet i Sverige. Passiva energirenoveringar som avser energiefterfrågesidan såväl som aktiva energirenoveringar som avser energiförsörjningssidan undersöktes tillsammans med deras kombinationer, vilket resulterade i åtta olika fall. De undersökta energirenoveringarna som avser energiefterfrågesidan är tilläggsisolering av vindbjälkslag och byte av fönster till isolerglas medan energirenoveringarna som avser energiförsörjningssidan är installation av solceller på taket och konvertering till vattenburen värme med bergvärmepump. Resultatet av denna studie visar att kombinationer av alla fyra energieffektiviseringsåtgärder har den högsta energibesparingspotentialen och ger den högsta NPV jämfört med de andra fallen för en antagen real kalkylränta på 3% och ett elpris på 1.60 SEK/kWh, samtidigt som det kräver högst CAPEX. Däremot, bergvärmepump med vattenburen värme kräver två gånger lägre CAPEX, samtidigt som det har hög energibesparingspotential och ger hög NPV.

The content of greenhouse gases in the atmosphere is increasing resulting in climate change and efforts to stop the negative trend need to be intensified. The energy use in the Swedish residential and service sector constitutes 40 % of the total energy use of 378 TWh in the country. Nationally there is a target to reduce the energy use per heated area with 20 % to 2020 and 50 % to 2050. Energy renovation of buildings from the Million Programme is foreseen to be able to contribute to achieving the targets owing to the large building stock and energy efficiency potential. In the master thesis cost optimal energy renovation strategies are investigated for two multi-family buildings in Linkoping built during the Million Programme, one with an unheated attic and one with a heated attic. The thesis is carried out by using life-cycle cost optimisation (LCC-optimisation) by utilising the software OPERA-MILP, developed at Linkoping University. The aim of the thesis is to obtain the energy renovation strategy that is optimal from an LCC-perspective and to investigate the energy reduction and LCC. Optimal energy renovation strategies are also investigated for energy renovation to levels of the Energy Classes of the National Board of Housing, Building and Planning in Sweden and the stricter limits for nearly zero-energy buildings (NZEB) that will likely come into force in 2021. Greenhouse gas emissions and primary energy use are also investigated for the different cases with the purpose of putting energy renovation in relation to climate impact. Local environmental factors are used for district heating while electricity is assigned values based on the Nordic electricity mix and Nordic marginal electricity respectively. The current LCC and annual energy use is 2 945 kSEK and 133 MWh for the building with an unheated attic and 3 511 kSEK and 162 MWh for the building with a heated attic. The result shows that LCC can be reduced by approximately 70 kSEK and 90 kSEK respectively. The optimal solution constitutes of a window change from windows with U=3,0 W/m2°C to windows with U=1,5 W/m2°C and results in a reduction of the energy use by 13 % and 15 % respectively. LCC increases with 240 kSEK for the building with unheated attic and decreases with 18 kSEK for the other building when Energy Class D is reached. Energy Class C is attained through an increase in LCC by 300 – 590 kSEK and Energy Class B through an increase by 1610 – 1800 kSEK. It is not possible to reach Energy Class A or the future requirements for NZEB (55 kWh/m2Aheated) with the energy renovation measures that are implemented in OPERA-MILP. The largest energy reduction that can be attained is approximately 60 %. The most cost optimal insulation measure is additional insulation of the attic floor/pitched roof followed by additional insulation of the ground concrete slab. It was shown to be more cost efficient to change to windows with U=1,5 W/m2°C in combination with additional insulation compared to changing to windows with better energy performance. For greater energy savings additional insulation on the inside of the external wall is applied, while insulation on the outside of the external wall is never cost optimal. To reach Energy Class B installation of HRV is required which gives a large increase in cost. Less extensive energy renovation is needed to reach the energy classes for the building with heated attic compared to the building with unheated attic. The annual use of primary energy in the reference case is 22 MWh for the building with an unheated attic and 26 MWh for the building with a heated attic. The emissions of greenhouse gases are 18 tonnes CO2e and 22 tonnes CO2e per year respectively when the emission factor of the Nordic electricity mix is applied and 20 tonnes CO2e and 25 tonnes CO2e respectively when the Nordic marginal electricity is applied. The yearly primary energy use can be reduced with up to 7 MWh through energy renovation. When the energy renovation leads to an increase in electricity use the primary energy can however increase with up to 12 MWh. The yearly greenhouse gas emissions can be decreased with up to 14 tonnes CO2e. When Nordic marginal electricity is applied to estimate the emissions of greenhouse gases for an energy renovation strategy that leads to an increase in electricity use the result is less beneficial from a climate perspective compared to when Nordic electricity mix is applied.

Energy efficiency of the building sector is a key strategy to achieve national climate goals in Sweden and other European countries. In this thesis, several renovation scenarios for a case study office building in Sweden are analysed and compared based on their energy performance, environmental impacts, and economic costs from a life cycle perspective. As a baseline, the case study building was simulated in IDA ICE and compared with the simulated renovation scenarios. For the Life Cycle Analysis (LCA) and the Life Cycle Costs (LCC), the commercially available software OneClickLCA was used. The renovation scenarios were carried out over three rounds: (i) material type scenarios where five insulation materials (glass wool, rock wool, hemp fiber, Expanded Polystyrene (EPS), and Extruded Polystyrene (XPS)) and two frame materials (wood and steel) are compared; (ii) insulation thickness optimization from economic and environmental performance perspectives (iii) comparison of combination with other typical renovation measures such as changing of windows, improving specific fan power, heat exchanger efficiencies, and lightings. The results show that glass wool gives the most economical and environmental performance, followed by rock wool and EPS. When considering other environmental indicators, hemp fiber presents the best environmental option. However, it is not competitive with traditional insulation materials from an economic perspective. The insulation thickness scenarios show different optimal economic and environmental performance points, giving total energy savings of 5 % and 9,5 %, respectively. When considering other typical energy efficiency measures, the highest impact on the energy performance was found when improving the specific fan power (SFP) and switching to LED lights with total electricity reductions (including user-based electricity consumption) of 4 % and 14 %, respectively. Conclusively, the case study showed how the electricity and heating demand of the studied office building could be reduced, and the environmental and economic consequences of the different energy-efficiency measures.

The dissertation thesis is focused on a methodology of optimal design energy renovation of school buildings. The thesis is focused on the analysis of selected school buildings during the last 100 years of construction in the first phase. At this phase, are found some important information, especially in terms of the energy performance of the building envelope and results of this parts. Last but not least, CO2 emissions were detected. In the next part of this work, one selected school is assessed in terms of the quality of the environment, due to the evaluation of microbial microclimate on building structures, CO2 concentration and daylight. CO2 concentration and classroom daylight is addressed both for the original and for the new state. Another point of this thesis is the appreciation of the size of the classrooms in the schools both in terms of typological principles and in terms of the average size of classrooms. The daylight assessment is performed on these selected sizes, which is a part of the "PaMo I" design tool. In the next phase of the dissertation was created the design tool "PaMo I". This tool solves the evaluation of the renovation of school buildings from the point of view of the thermal engineering in connection with the influence of the daylight illumination on the classrooms of the school buildings by the thickness of the insulation system and the replacement of the windows. Part of the design tool is also the financial quantification of the investment, the payback period and the impact on the environment of the individual variants. The choice of variant options has been used when making a design tool user decision. The result of this work is a design tool which will help in deciding and finding the optimal alternative to the energy renovation of a school building in connection with daylighting inside classrooms.