This paper deals with the usage of photovoltaics in positive energy buildings. The European Union published in 2010 a directive about the energy performance of buildings in which article 9 states that all member States shall ensure that by the end of 2020 all new buildings should be “nearly zero-energy” buildings (by the end of 2018 for public buildings). This kind of nearly zero-energy buildings is starting to develop in France under the name “BEPOS” (which stands for POSitive Energy Building, in French), and this is the name that will be used in this document. 288 projects have been certified “BEPOS” as of 2012, according to the ADEME which published a map of all the BEPOS buildings in France (the ADEME is a French agency for the environment and the energy utilization, which is a major actor in the French energy policy, often deciding where to allocate funds). To be a BEPOS, these buildings need to produce electricity on site and photovoltaics are often considered as one of the most mature and competitive technology to do so, also the most used. The purpose of this study is to demonstrate that photovoltaics are an economically viable means to reach the BEPOS quality label, and to provide data to quantify the cost and performance of a photovoltaic system. To achieve that, the technological and market conditions of photovoltaics in France are reviewed, and techno-economic calculations are made using data provided by solar and construction companies.

I detta examensarbete studeras kommande energikrav för byggnader i Sverige och i synnerhet kraven på specifik energianvändning. Detta mot bakgrund av EU-kommissionens och EU-parlamentets direktiv, EPBD2, om nära nollenergibyggnader 2020. Därefter bearbetas ett förslag på en ny ytterväggskonstruktion som med lägre U-värde än den befintliga ytterväggen ska sänka Fiskarhedenvillans olika hustypers specifika energianvändning. Syftet med sänkningen är att möjliggöra för Fiskarhedenvillan att uppfylla de kommande energikraven. Det är många parametrar som måste uppfyllas och det nya ytterväggsförslaget analyseras förutom ur energisynpunkt även med hänsyn till statik, fukt och kostnad. Beräkningar för statik och specifik energianvändning har gjorts för ett referenshus. Resultatet av att byta ut den befintliga ytterväggskonstruktionen mot det framarbetade förslaget med ca 33 % lägre U-värde gav endast en sänkning med ca 6 % av den specifika energianvändningen. För att sänka referenshusets specifika energianvändning ytterligare bör även resterande delar av klimatskalet förbättras samt ett annat uppvärmningssätt väljas. Avslutningsvis diskuteras resultatet och vi lämnar rekommendationer för fortsatta studier. / This thesis studies future energy requirements for buildings in Sweden and in particular the requirements for specific energy use. This is in light of the European Commission and European Parliament Directive, EPBD2, on nearly-zero energy buildings 2020. A proposal for a new exterior wall construction in Fiskarhedenvillan houses with lower U-value than the existing exterior wall is analyzed. The purpose of the new wall is to reduce the specific energy use to enable Fiskarhedenvillan to meet the future energy requirements. There are many parameters that must be considered. The proposed new exterior wall construction is analyzed not only from the energy point of view but also with regard to statics, moisture and cost. Calculations for the statics and the specific energy use have been made for a reference building. The changed design of the exterior wall resulted in a reduction of the U-value with 33 % but only 6 % of the specific energy use. A further reduction of the specific energy use for the reference house requires improved design of the remaining building envelope and a new heating method. Furthermore the results are discussed and recommendations for further studies are given,

The aim of the diploma thesis is the processing of the design documentation for the construction of a boarding house with nearly zero energy consumption. The plot is located in the cadastre unit Znojmo-Louka, in a buildable area for recreation. The new building is detached, with partial basement, and has two floors. There is a preparation area in the one-storey section, including a dining area. Accommodation units can be found in a two-storey segment. And there is a technical background of the building in the basement. The vertical load-bearing system is made of ceramic blocks and concrete poured fittings used in the basement. The horizontal structures are formed cast-in-place reinforced slabs. The building is covered with a warm flat vegetation roof and a cold roof made of truss girders. The building is insulated with a contact thermal insulation system made of polystyrene. The building is based on deep piles and foundation reinforced concrete strips.

This doctoral thesis proposes a new method of energy retrofitting of existing residential buildings towards nearly zero-energy status. The topic of energy retrofitting of existing buildings is widely discussed and lamented within the European Union and the Member states and is enshrined in the Directive 2010/31/EU. This research is in line with the European Union strategy Europe 2020 which sets targets for climate change and energy sustainability. The thesis describes the study of building energy performance of a pilot energy retrofitted residential building towards nearly zero-energy where progressive design technologies, such as energy modelling, monitoring, building optimisation and verification were used. This case study helped to formulate the recommendations on the effectiveness of various passive and active design methods together with renewable energy systems and after the extensive research it contributes to model and verify the future expectation and energy efficiency requirements of the residential market.

Without decarbonizing cities energy and climate objectives cannot be achieved as cities account for approximately two thirds of energy consumption and emissions. This goal of decarbonizing cities has to be facilitated by promoting net-zero/positive energy buildings and districts and replicating them, driving cities towards sustainability goals. Many projects in smart cities demonstrate novel and groundbreaking low-carbon solutions in demonstration and lighthouse projects. However, as the historical, geographic, political, social and economic context of urban areas vary greatly, it is not always easy to repeat the solution in another city or even district. It is therefore important to look for the opportunities to scale up or repeat successful pilots. The purpose of this paper is to explore common trends in technologies and replication strategies for positive energy buildings or districts in smart city projects, based on the practical experience from a case study in Leipzig—one of the lighthouse cities in the project SPARCS. One of the key findings the paper has proven is the necessity of a profound replication modelling to deepen the understanding of upscaling processes. Three models analyzed in this article are able to provide a multidimensional representation of the solution to be replicated.

Objectives set by the EU means that all buildings after 2020 has to be nearly zero energy buildings. This means that thicker layers of insulation have to be added in the wall construction which makes the wall thicker. It means that the living area will be reduced. Vacuum insulation is a highly effective type of insulation and because of its low thermal conductivity it has the ability to reduce the thickness in wall structures. This project investigates a proposal to apply vacuum insulation in one-storey buildings. In order to achieve the goals of the project, a proposal for a one-storey building was developed. Calculations have been made and the proposal was developed as an alternative to show how to construct a family home containing vacuum insulation. The empirical data was collected through interviews, document analysis and literature studies. The collected data was analyzed together with the theoretical framework that has been developed through literature studies and document analysis. Creating a wall construction containing vacuum insulation as a primary insulation usually means that the wall will be considerably thinner than a wall construction with traditional insulation. This means that living area can be saved. Vacuum insulation has to be protected properly as it is easily punctured where upon it loses the most of its insulation capacity. Vacuum insulation is not common on the Swedish construction market today, this is due to many factors, including its high price. Vacuum insulation is a good problem solver which can be used in bay windows to gain extra space. One can also make use for it in tight spaces. From an economic point of view vacuum insulation offers the greatest advantages in cities where living space is considerably higher than in rural areas. To take part of the work there is no need for prior knowledge about vacuum insulation. The project focuses only on wall structures in the single-storey villas, therefor, no indentations has been made on the floor- and roof structures or other building types. The project only focuses on newly constructed buildings. No calculations are made for moisture or production costs. / Mål uppsatta av EU innebär att samtliga byggnader som uppförs vid år 2020 måste vara nära-nollenergihus. För väggarna i konstruktionen innebär det att tjockare lager av isolering måste adderas vilket ger bredare väggkonstruktioner. Bredare väggkonstruktioner innebär även att boarean minskas. Vakuumisolering är ett högeffektivt isoleringsmaterial som genom sin låga värmeledningsförmåga har möjligheten att minska tjockleken vid väggkonstruktioner på grund av dess tunna skikt. Arbetet utreder ett förslag att applicera vakuumisolering i enplansvillor. För att uppnå arbetets mål har ett förslag på enplansvilla tagits fram. Beräkningar har gjorts och förslaget är framtaget som ett alternativ för att visa hur en villa innehållande vakuumisolering kan utformas. Det empiriska materialet har samlats in genom intervjuer, dokumentanalyser samt litteraturstudier. Empirin analyseras sedan tillsammans med det framtagna teoretiska ramverket genom litteraturstudier och dokumentanalyser. Att skapa en väggkonstruktion med vakuumisolering som primär isolering betyder oftast att väggen blir avsevärt mycket tunnare än en väggkonstruktion av traditionell isolering, vilket betyder att boarea kan sparas. Vakuumisolering måste skyddas på rätt sätt i väggkonstruktioner eftersom materialet lätt punkteras varpå det förlorar den största delen av sin isoleringsförmåga. Idag är inte vakuumisolering utbrett på den svenska byggmarknaden vilket beror på många faktorer, bland annat dess höga pris. Vakuumisolering är en väldigt bra problemlösare som med fördel kan användas i burspråk för att vinna extra utrymme. Det kan även användas i trånga utrymmen som elnischar. Ur ekonomisk synpunkt ger vakuumisolering störst fördel i städer där boarea per kvadratmeter är högre än motsvarande på landsbygden. För att ta del av arbetet krävs inga förkunskaper om vakuumisolering. Arbetet fokuserar endast på väggkonstruktioner i enplansvillor, därför har inga fördjupningar skett på golv- och takkonstruktioner eller andra byggnadstyper. Enbart nybyggnationer av trästommar är utrett. Beräkningar är inte gjorda för fukt och produktionskostnader.

This thesis investigated application of the heat recovery ventilation using an exhaust air heat pump and a roof top photovoltaic (PV) system for a group of three multi-family houses located in Ludvika, Sunnansjö. The buildings in the existing condition have mechanical ventilation and a centralized heating system consists of a pellet boiler as the main source and an oil boiler as back up. Exhaust air heat pump (EAHP) has been known by the previous relevant researches as an effective solution to promote the energy efficiency in the buildings. Furthermore, reduction in PV cost has made the PV as a financially viable option to be contributed in supplying electricity demand. In this respect, this thesis aimed to calculate the potential of energy saving in the case study using the combination of EAHP and PV. For this purpose, the buildings and the proposed energy system were simulated to enable the comparison of energy demand before and after the renovation. The simulation was gradually progressed through several phases and each stage created the prerequisites of the next. Since the buildings were relatively similar in terms of boundary conditions, one of the buildings were initially modeled and the concluded space heating (SH) demand was extrapolated to the three buildings scope. The simulation of the building was done using 3dimensional thermal model offered by Trnsys3d. The primary results were also calibrated against the available annual fuel consumption data. In the second phase, a pre-developed TRNSYS model of the energy system was completed using the result of previous step as the total SH demand as well as the estimated domestic hot water (DHW) consumption from a stochastic model. This simulation produced the electricity demand profile of the heat pump when the heat pump provided the total heat demand. Subsequently, the electricity consumption of the flats and operational equipment were estimated using stochastic model and available monthly measurement, respectively. Since the feasibility and optimal placement of 74 𝑘𝑊 PV modules offered for these buildings had been already examined by the author in another study, the final simulation were performed in an hourly basis considering PV production and total electricity demand; i.e. EAHP, flats consumption and operational equipment. The results of the simulation showed that 21 % of total electricity demand during a year could be supplied by the proposed PV system even without any electrical storage, whereas 74 % of total yearly PV production is consumed by the local loads. The results also proved that removing old inefficient oil boiler and supplementing the pellet boiler with the combination of EAHP and PV could mitigate the annual purchased energy (including electricity and pellet) by approximately 40 % compared to the current condition.

Purpose: This degree project aims to see how the energy demand from active heating of detached houses can be improved to meet the energy performance requirements set for nearly zero-energy buildings by Boverket (The Swedish National Board of Housing, Building and Planning). Method: To accomplish this, the benefits from two different energy-saving installations are studied: bedrock heat pumps and heat exchangers in Heat Recovery Ventilation Systems (HRV-systems). These are then compared in a new and an older detached house with very different heat losses. There are several reports of energy-saving systems in detached houses. What distinguishes this work is that it compares the specific results from the added energy-saving system depending on whether it was added first or last. The older detached house is an important part of this work as it represents a possible impact on parts of the existing housing stock with a similar technical standard. The energy balance for the buildings is calculated monthly with all contributions from passive heat considered, and with the energy demand for active heating as the main result. Results: It is very difficult to meet the energy performance requirements for an older detached house without extensive measures or renovations. The HRV-system had a low to very low impact. Both types of detached houses have a lot to gain from an investment in bedrock heating, especially the older one that has high energy demands. However, the new detached house with a higher technical standard in the building envelope, was the only one to meet the energy requirements with the bedrock heat pump on its own. Conclusion: Bedrock heating can be a very profitable investment as it provides heat both for the active heating of the building as well as for the domestic hot water. In order to meet tougher energy requirements, the bedrock heat pump may need to be accompanied by an improved and more energy-efficient building envelope and the supply of self-produced electricity, such as solar cells. HRV-systems require a good air tightness and an energy-efficient building envelope to be profitable. In older detached houses, it is not a profitable investment, as it does not have sufficiently large proportions of controlled ventilation to work with. In newer houses the proportion of controlled ventilation is bigger, but the amount of heat loss that can be affected is still not as big as the energy savings a bedrock heat pump can bring.

The aim of this master thesis is to design a seven-storey office building in Hodonín, Czechia. The building has retail spaces in the basement and first floor and offices in second to sixth floors and utility room and elevator engine room in the seventh floor. Individual floors are accessible via stairs and elevator. The vertical load-bearing structure consists of reinforced concrete walls and columns. Horizontal load-bearing structure consists of cast-in-place reinforced concrete slabs. The roof is flat with photovoltaic power plant connected to main battery. The main source of heating energy for the building is a heat pump (air-water) backed by a secondary electric boiler. Fresh air is supplied by a HVAC unit installed on the roof. Overheating due to solar heat gains and equipment is mitigated by local AC ceiling units. Automated roller blinds reacting to solar gains and glare are installed over the windows. The next part of thesis consists of comparison of pressure properties of sheet metal duct and CLIMAVER system.

[pt] Uma arquitetura que exige uma enorme demanda de energia contraria o conceito de um Edifício de Energia Quase Zero (em inglês Nearly Zero Energy Building - NZEB). Pesquisas indicam que edifícios de alto desempenho podem ser alcançados com um design integrado que combina estratégias de eficiência energética, como vidro de alto desempenho, com energia fotovoltaica. A metodologia BIM pode incorporar a Análise de Desempenho do Edifício para apoiar a tomada de decisão de um projeto integrado, essa abordagem é considerada essencial para alcançar um NZEB bem-sucedido. A presente investigação inclui uma revisão sistemática da literatura que orientou a pesquisa. Com base na SLR, foi desenvolvido um Manual de Entrega de Informações que propõe um novo fluxo de trabalho no qual os estudos de energia são realizados nos estágios iniciais do design para alcançar projetos com maior eficiência energética e aproveitar a colaboração intrínseca à metodologia BIM. Por fim, é apresentado um experimento hipotético de um edifício comercial para ilustrar o fluxo de trabalho proposto no IDM desenvolvido. O software Autodesk Revit foi usado para modelar o edifício e a simulação energética foi realizada no software DesignBuilder. Verificou-se que, para que esses dois softwares fossem interoperáveis, o modelo precisava ser exportado do Revit no formato gbXML. As opções de design foram baseadas na proporção de janela/parede (30 por cento, 50 por cento e 100 por cento), no vidro adotado e no sistema fotovoltaico. A análise de viabilidade econômica foi realizada com base no Valor Presente Líquido e na Taxa Interna de Retorno. Os resultados indicaram que o uso da fachada norte para produção fotovoltaica combinado com o sistema fotovoltaico da cobertura forneceu um balanço de energia próximo de zero na maioria dos casos. Por fim, todos os casos analisados têm um tempo de retorno de investimento inferior a garantia do fabricante dos módulos fotovoltaicos (25 anos), exceto no caso com 100 por cento de relação janela/parede e vidro PV na fachada norte. / [en] An architecture that requires a huge energy demand goes against the concept of a Nearly Zero Energy Building (NZEB). Research on the subject indicates that high performing buildings can be achieved with an integrated design that combines energy efficiency strategies, such as high performing glass, with photovoltaic energy (PV). The Building Information Modeling (BIM) methodology can incorporate Building Performance (BP) analysis to support decision making of an integrated design, which is considered essential to achieve a successful NZEB. The present investigation includes a Systematic Literature Review (SLR) that guided the research. Based on the SLR, an Information Delivery Manual was developed that propose a new workflow in which the energy studies are performed in the early stages of design to achieve more energy efficient projects and take advantage of the collaboration intrinsic to the BIM methodology. Lastly, a hypothetical experiment of a commercial building is presented to illustrate the workflow proposed in the developed IDM. The Autodesk Revit software was used to model the building and the energy computer simulation was performed in the DesignBuilder software. It was found that for these two software tools to be interoperable, the model had to be exported from Revit in gbXML format. The design options in the experiment were based on window-to-wall ratio (30 per cent, 50 per cent and 100 per cent), on the adopted glass, and on the photovoltaic system. The economic feasibility analysis was performed based in the Net Present Value (NPV) and the Internal Rate of Return (IRR). The results indicated that the use of the north facade for PV production combining with the PV roof system provided a nearly zero energy balance in most of the cases. Finally, all cases analyzed had a payback time of less than the PV module manufacturer guarantee (25 years), except for the case with 100 per cent window-to-wall ratio and PV Glass in the north facade.