In Sweden, the housing sector accounts for about 40% of the country's energy consumption. Theself-contained houses account for about 20% of this energy consumption (Energimyndigheten,2021). Boverket is the authority in Sweden that regulates the laws and regulations that affectenergy use (Boverket, 2016). In addition to Boverkets regulations, there are external organizationsthat drive development to minimize households' energy use (Feby, 2019). One of theseorganizations is FEBY, they have designed requirements that can be used as a complement to theBBR requirements. The organization has developed the parameter heat loss rate, which calculatesthe buildings heat loss.This study has been carried out in collaboration with the house manufacturer Jörnträhus AB. Thegoal of the work has been to develop a house that meets FEBY 18's requirements for heat loss rateand then verify the house's performance against Boverkets energy classification. The study wasbased on a reference house provided by Jörnträhus. The house was modeled in the energy programVIP-Energy and then analyzed. After the analysis, it was found that the reference house's VFTreaches 58.15 W / m2Atemp. Thereafter, the house was remodeled in VIP-Energy with changes tothe constructions and the ventilation system. With these changes, the VFT was calculated at 27.49W / m2Atemp and achieves the bronze level for FEBY 18.Finally, four simulations were performed to check the primary energy of the house during differentscenarios. All simulations were carried out in Skellefteå municipality but with different conditions.Two of the simulations were carried out at a location with open space and the other two simulationswere performed at a enclosed location with much shadow. In the different scenarios, the heatingand ventilation systems were varied. The simulations showed that wind and solar heat loads canhave a greater impact on primary energy than some technical solutions like heat recovery in theventilation.

<p>Background: The most energy efficient houses today are so called passive houses. These houses achieve high energy-efficiency partly by having well insulated walls. U-value describes the amount of heat transfered through a building element, the more insulation, the smaller U-value. A typical passive house wall have a U-value of 0.10 W/m2,°C. The passive houses are primarily made as small family houses and not as a block of apartments. This is partly because the bigger houses often are made of prefabricated walls, which at present times are not made with enough insulation. One construction method common in prefabrication is a sandwich-construction with two layer of concrete surrounding a core of cellular plastic. Skanska is making this type of walls in a factory on Gotland. </p><p>We wanted to combine the energy efficiency of passive housing with the efficiency of </p><p>prefabricated sandwich-walls. </p><p>Aims: To present a suggestion of a sandwich-construction made with concrete and cellular plastic with a U-value below 0.10 W/m2,°C, that could be implemented in the factory on Gotland. </p><p>Methods: By analyzing systems of today we developed two different models that have a U-value below 0.10 W/m2,°C. The first system was developed from a system used in Skanska’s factory on Gotland and the second one was based on a system delivered by Halfen DEHA. This was made through empirical tests and theoretical calculations. We compared the developed systems in terms of the conditions in Skanska’s factory on Gotland. </p><p>Result and discussion: The system based on Halfen DEHA needs a larger amount of shackles, than the system developed from Skanska’s present system. This leads to the need of thicker insulation to achieve the desired U-value. The reason is that the Skanska-based system uses a combination of shackles and cellular plastic to carry the loads of the coating layer while the Halfen DEHA depends on the shackles alone. We believe that the first of our two developed systems is the best in terms of the ease in adopting to the production method in Skanska’s factory. The second system is safer in terms of controlling the production and has the possibility to have an air gap. </p><p>Conclusion: In the rapport we present a sandwich-construction system that has a U-value below 0.10 W/m2,°C, that we believe would work for prefabrication of wall structures and could be easily adopted in Skanska’s factory on Gotland.</p>

Under the pressure of energy shortage, energy saving has become one of the most important topics. The world isseeking different ways to follow the sustainable development concept and to solve the energy shortage crisis.This thesis is based on the idea of improving energy efficiency in the building industry which is one of thebiggest energy consumption industries. The aim of this paper is to simulate a renovation of an existing oldbuilding in Sweden according to the concept of building a Swedish Passive House and to see how much energycould be saved after the renovation. The target building Taljstenen 7A-C was built in 1960 in Uppsala and itbelongs to the housing company Uppsalahem. The target building is facing extensive renovation due to its age.An energy consumption model of the present building was built by the software VIP-Energy after measurementsand calculations. Based on the model, three important improvements are made in a simulative renovation process.The three improvements are insulating building envelope, installing a new FTX ventilation system with highefficient heat recovery system and installing solar collectors for hot top water and space heating. The resultsshow a significant reduction of energy consumption of the renovated building compared to the original onewhich is from 516MWh per year decreased to 371MWh. Although the renovated building did not completelyfulfil the Passive House Standard in Sweden, it still has improved to be a low energy building. The purpose ofsaving energy can be achieved.

Background: The most energy efficient houses today are so called passive houses. These houses achieve high energy-efficiency partly by having well insulated walls. U-value describes the amount of heat transfered through a building element, the more insulation, the smaller U-value. A typical passive house wall have a U-value of 0.10 W/m2,°C. The passive houses are primarily made as small family houses and not as a block of apartments. This is partly because the bigger houses often are made of prefabricated walls, which at present times are not made with enough insulation. One construction method common in prefabrication is a sandwich-construction with two layer of concrete surrounding a core of cellular plastic. Skanska is making this type of walls in a factory on Gotland. We wanted to combine the energy efficiency of passive housing with the efficiency of prefabricated sandwich-walls. Aims: To present a suggestion of a sandwich-construction made with concrete and cellular plastic with a U-value below 0.10 W/m2,°C, that could be implemented in the factory on Gotland. Methods: By analyzing systems of today we developed two different models that have a U-value below 0.10 W/m2,°C. The first system was developed from a system used in Skanska’s factory on Gotland and the second one was based on a system delivered by Halfen DEHA. This was made through empirical tests and theoretical calculations. We compared the developed systems in terms of the conditions in Skanska’s factory on Gotland. Result and discussion: The system based on Halfen DEHA needs a larger amount of shackles, than the system developed from Skanska’s present system. This leads to the need of thicker insulation to achieve the desired U-value. The reason is that the Skanska-based system uses a combination of shackles and cellular plastic to carry the loads of the coating layer while the Halfen DEHA depends on the shackles alone. We believe that the first of our two developed systems is the best in terms of the ease in adopting to the production method in Skanska’s factory. The second system is safer in terms of controlling the production and has the possibility to have an air gap. Conclusion: In the rapport we present a sandwich-construction system that has a U-value below 0.10 W/m2,°C, that we believe would work for prefabrication of wall structures and could be easily adopted in Skanska’s factory on Gotland.

xiv, 92 p. : ill. (some col.) / Passive House is a voluntary, performance-based energy standard for buildings. Passive Houses use on average 90% less energy for space conditioning than code-designed houses; Passive House therefore offers an ambitious performance target for home energy retrofits. Retrofits built to the Passive House standard in Europe have demonstrated a high level of energy performance. In the U.S., few Passive House retrofits exist to date; for this reason, design and cost information for such retrofits is lacking. This study establishes an exemplar through designing the Passive House retrofit of an older home in Eugene, Oregon. The retrofit's cost-effectiveness was examined by comparing projected "business as usual" (BAU) life cycle costs to those associated with retrofit. While the BAU scenario resulted in the lowest cost over a 30-year life cycle, the difference is relatively small; minor adjustments to key variables make the retrofit financially viable. / Committee in charge: Dr. Alison G. Kwok, Chairperson; Peter Keyes, Member; Jan Fillinger, Member

The master thesis deals with passive houses and their profitability's economic analysis. The thesis focuses on both new buildings and renovations, which have the greatest potential for energy savings in the building's sector. The cost-effectiveness of proposed measures is evaluated using the example of reconstruction of an existing house with passive and low-energy standard. Low-energy option of reconstruction is more profitable from an investor's perspective than the passive one. At 4% annual growth in energy prices, both options become comparable. The result of the calculation is not generally applicable. The profitability always depends on a specific building and various measures. Besides the cost-effectiveness, the investor's decision about an investment is also influenced by an increasing level of living comfort, subsidies and environmental protection.

This diploma thesis examines the economics of use of technologies linked with low-energy, passive, and active house construction which is presently very often a topic of interest. The goal of the thesis is to evaluate economic effectivity of additional investment into construction materials leading to reduction of heating requirements of the evaluated family house. Furthermore, economics of the use of advanced technologies of ventilation, different heat sources and photovoltaic power plant are assessed. The result is a complex evaluation of different alternatives of the house which makes this thesis helpful in answering the question whether these additional investments will pay off.

The aim of this thesis is the design and building services systems in buildings with energy close to zero. The thesis 2 variants were designed heating and DHW. In variant 2 is considered with the photovoltaic system to generate electricity that is used up mainly in the building. It is part of the thesis experiment, whose aim was to monitor and evaluate the structure of electricity consumption in the residential unit.

I detta examensarbete har energiberäkningar och analyser enligt FEBY12 gjorts på ett radhusområde för att undersöka vad som krävs för att lågenergihusen ska uppnå passivhusstandard. Att uppföra energisnåla byggnader är i dagens samhälle viktigt för alla företag eftersom människor blir allt mer energimedveten och krav från beställare blir allt högre. I arbetet har en modell av radhusområdet modellerats i Revit Architecture för att på ett smidigt sätt få korrekta värden i de olika energiberäkningsprogrammen Vasari, Energihuskalkyl och PHPP. Programmen har helt olika kvalitéer därför har en jämförelse och analys av programmen utförts. Analyser har tydligt visat att det krav som finns för att uppnå passivhusstandard på värmeförlusttalet är betydligt svårare att uppnå än det krav som ställs på den levererade energin. För att uppnå passivhusstandard vidtogs diverse åtgärder såsom U-värde för väggar förbättrades, ventilationsaggregatets verkningsgrad höjdes samt fönsterpartierna reducerades avsevärt. / Energy calculations and analysis have in this thesis paper been made in accordance with the FEBY12 on a row house area to examine what is needed for low energy houses to achieve passive house standards. The ability to construct energy efficient buildings in today’s society is very important for all companies in the business since the people are becoming more and more environmentally conscious and demands from buyers are increasing.  To be able to efficiently obtain accurate values from the different energy calculation programs such as Vasari, Energihuskalkyl and PHPP for this examination, a model was created using Revit Architecture. The programs’ quality strongly differs from each other and therefore analysis and comparisons have been made to reach a result. Analysis clearly shows that the demands to reach passive house standard on rates of heat loss are significantly harder to meet than the demands put on the supplied energy.  To achieve passive house standard several different measures were taken, for example the U-value in the walls were improved, ventilation was made more efficient and the window panels were reduced significantly.

Some passive houses are provided a warm supply flow inlet coming from a mechanical ventilation system, creating issues of shortcut ventilation as a result of an originated density layer stratification, since the supplied warm air is confined to the ceiling level. In this way, there exist several complaints of thermal discomfort and poor indoor environmental quality in passive houses. Thus, a method of periodic variation of the ventilation supply frequency is an option to increase mixing, aimed at de-stratifying the room conditions. A small-scale water model is employed in order to systematically explore the influence of the created standing waves from the supply input frequency and its interaction with stratification characteristics in the studied volume, hence operating with water as a working fluid and a paddle as an oscillating mechanical input. Measurements at three different input frequencies and at three input paddle locations have been performed, gathering vertical temperature gradients and visualization data from them. Thus, ventilation efficiency of passive houses is set to improve, consequently increasing their public acceptability, via reaching buoyancy resonance, i.e., matching the input frequency with the internal Brunt-Väisäla frequency of the fluid. Consequently, the shortcut ventilation issues may be mitigated and the public acceptability of passive houses increased, achieving a higher thermal comfort and economic and energy demand savings, while enhancing sustainable and renewable heating alternatives such as the heat recovery from the outgoing exhaust flow.