Improving the energy performance of detached houses is expected to play an important role in achieving energy and climate targets in Sweden. The majority of detached houses require energy renovations due to technical deteriorations in heating, ventilation, and air conditioning systems approaching the ends of their lives. Renewable energy supply system implementation leads to total energy use reduction. No previous studies provided information regarding how possible climate futures could affect subsidies required to implement these systems. This study compared the performance of an air-to-water heat pump (ASHP), a ground-source heat pump (GSHP), and an integrated system of a ground-source heat pump and photovoltaic solar panels (GSHP-PV) in reducing the total energy use of a detached house, which was initially supplied by an electric boiler. The performances of the supply systems were analysed in regard to three different climate scenarios, following the Special Report of Emissions Scenarios, A2 storyline. The effects of three different interest rates and two different lifetimes on subsidies were also investigated for all three energy supply systems. The GSHP-PV system was the most efficient system, as it secured 97%–100% of the total energy consumption, followed by GSHP and AWHP. The analyses of the results showed that variations in future climate conditions changed the subsidies required to install the supply systems. Furthermore, the results showed that changes in lifetime had greater impact on subsidies than interest rate growth.

Floor heating and radiators are two of the most common types of hydronic heating systemsused for space heating in single-family houses in cold climate regions. Notwithstanding, there are fewcomparative studies on indoor temperature distribution and system cost evaluations for radiatorsand floor heating. Furthermore, there are no aligned outcomes in terms of total heat supply fora single-family house with radiators or floor heating. In this study, the eect of building energyeciency level and construction type, including flooring material, on the supply heating demand andtransmission heat losses were studied for both radiator and floor heating systems. For this purpose,a single-family house located in Växjö, Sweden, was modeled as a case study. The heating demandwas supplied with a district heating system with a similar supply temperature at 45 C for both theradiator and floor heating system. A sensitivity analysis was also performed to assess the eect offlooring configurations on the annual supply heating demand for both conventional and passiveversions of the case-study building. The results showed that the radiator-integrated building had alower supply heating demand in comparison with the floor heating-integrated buildings. Based onthe sensitivity studies, the flooring material did not have a significant influence on the supply heatingdemand and on the transmission heat losses in the case of the radiators. The supply heating demandwas only reduced up to 3% if the flooring U-value was improved by 60%. The results also showedthat refurbishment in a standard conventional building with a radiator heating system based on thepassive criteria led to a 58% annual energy savings, while this amount for a building with a floorheating system was approximately 49%.

The majority of the single-family houses in Sweden are affected by deteriorations in building envelopes as well as heating, ventilation and air conditioning system. These dwellings are therefore in need of extensive renovation, which provides an excellent opportunity to install renewable energy supply systems to reduce the total energy consumption. The high investment costs of the renewable energy supply systems was previously distinguished as the main barrier in the installation of these systems in Sweden. House-owners should therefore compare the profitability of the energy supply systems and select the one, which will allow them to reduce their operational costs. This study analyses the profitability of a ground source heat pump, photovoltaic solar panels, and an integrated ground source heat pump with a PV system, as three energy supply systems for a single-family house in Sweden. The profitability of the supply systems was analysed by calculating the payback period (PBP) and internal rate of return (IRR) for these systems. Three different energy prices, three different interest rates, and two different lifespans were considered when calculating the IRR and PBP. In addition, the profitability of the supply systems was analysed for four Swedish climate zones. The analyses of results show that the ground source heat pump system was the most profitable energy supply system, since it provided a short PBP and high IRR in all climate zones when compared with the other energy supply systems. Furthermore, results show that increasing the energy price improved the profitability of the supply systems in all climate zones.

The current state of window and blind design moves beyond evaluating a single function, such as energy consumption, to include a human perspective in architectural design approach to create value. A current thought among architects and design professionals is that the highest value outcomes can be obtained when any architectural design contributes to enhanced well-being. Previous studies show that an individual’s well-being is determined by five main life domain factors: health, economy, personality, demographic variables and behavior variables. However, the life domain factors health and economy show stronger and more positive correlations to well-being. At this point, value creation within architectural design context, including window and blind design, can be seen as an attempt to enhance well-being by improving health and providing economic benefits for clients. Clients can represent i) owners who own a built asset, ii) investors who commit capital and expect to obtain financial return, or iii) occupants who live or work in the building every day. In the context of owner-occupied buildings, the value creation process is mainly seen as an attempt to enhance well-being for one entity by improving health and providing economic benefits. When considering investment properties or assets held for sale, the value creation process is mainly translated into an attempt to enhance well-being for several entities by improving health for occupants and providing economic benefits for owners and/or investors.Selecting a window and blind design to enhance client well-being remains a challenging task due to three main difficulties. The first difficulty relates to the contradictory effects of windows and blinds on visual and thermal comfort, energy consumption and life cycle cost. The second difficulty is the availability of a variety of window and blind designs in different sizes, positions and forms, making the selection of windows and blinds an intricate decision challenge for architects and designers. The third difficulty involves decisions about the selection of windows and blinds that should include all criteria and their interactions simultaneously.To resolve the abovementioned difficulties, this research applied the analytical hierarchy process (AHP) as a multi-criteria decision-making method to select a window and blind design based on a trade-off between visual comfort, thermal comfort, energy consumption and life cycle cost. The analyses of results show the capability of AHP in resolving difficulties, however its application is mainly limited to a small number of designs. To overcome this limitation, a decision-making framework was developed based on integration between non-dominated sorting genetic algorithm-II (NSGA-II) as an optimization algorithm and AHP. The strength and limitations of the decision-making framework were later tested by employing it in window and blind design practice. To investigate further benefits from the implementation of the framework, it was expanded by evaluating additional building envelopes, i.e. windows as well as external walls, roof and floor constructions, which made it possible to select a trade-off construction solution. The analyses of results show the framework’s ability to resolve difficulties and locate a trade-off design in a relatively short period of time. However, the decision-making framework only allows the analysis of the objective criteria for evaluating visual comfort, thermal comfort, energy consumption and life cycle cost. This is because it is necessary to rely on the creativity of the architects and designers when designing windows and blinds in order to consider subjective issues. The decision-making framework can be used either by design teams or customer service experts in window manufacturing companies. A literature study was therefore conducted to extend the technology acceptance model and thereby investigate the determinants of framework user acceptance of the decision-making framework. The results showed that organizational, individual, technological and environmental characteristics were the most influential external variables when investigating determinants of framework user acceptance of the framework. Organizational characteristics included top management support, training, organizational culture, and organizational size, while individual characteristics included the users’ previous knowledge and experience. Technological characteristics embraced information quality and system quality, meanwhile environmental characteristics comprised fulfillment of regulations and competitiveness.

Utformningen av fönster och solskydd omfattar idag mer än att utvärdera en enda egenskap såsom energiförbrukning. Istället är fokus på helheten med det mänskliga perspektivet i design med syftet att skapa värde. De högsta värdena kan uppnås när en arkitektonisk design bidrar till att förbättra välbefinnandet hos människan. Välbefinnandet kontrolleras av de fem huvudsakliga faktorerna hälsa, ekonomi, personlighet, demografi och beteendevariabler. Bland faktorerna visar hälsa och ekonomi starkast och mest positivkorrelation med välbefinnande. En design kan skapa värde när det ökar kunders välbefinnande genom att förbättra hälsan och stärka ekonomin. Kunderna representerar bland annat ägare som äger en byggnad, investerare som satsar kapital och förväntar sig att få ekonomisk avkastning och boende som bor eller arbetar i byggnaden varje dag. Att skapa värde i samband med privata fastigheter kan ses främst som ett försök att öka välbefinnandet för vissa intressenter genom att förbättra hälsan och stärka ekonomin. Att skapa värde när man bygger fastigheter för uthyrning eller försäljning kan ses främst som ett försök att öka välbefinnandet genom att förbättra hälsan för boende och stärka ekonomin för ägare eller investerare.Att välja ett fönster och ett solskydd för att förbättra kundernas välbefinnande förblir en utmanande uppgift på grund av tre huvudsakliga svårigheter. Den första svårigheten avser de motsägelsefulla effekterna av fönster och solskydd på visuell och termisk komfort, energiförbrukningen och livscykelkostnaderna. Den andra svårigheten handlar om tillgången på ett stort antal olika fönster- och solskyddsdesign i olika storlekar, placeringar och former, vilket leder till att valet av fönster och solskydd blir till ett komplicerat problem. Den tredje svårigheten innebär beslut om val av fönster och solskydd som borde fokusera på alla kriterier (relaterade till den visuella och termiska komforten, energiförbrukningen och livscykelkostnaderna) och deras interaktioner samtidigt.För att lösa de ovannämnda svårigheterna användes den Analytical Hierarchy Process (AHP) metoden för att välja fönster och solskyddsdesign baserad på avvägning mellan visuell komfort, termisk komfort, energiförbrukningen och livscykelkostnaderna. Resultaten påvisar AHP metodens förmåga att lösa svårigheter men dess tillämpning är huvudsakligen begränsad inom ett litet antal designalternativ. För att övervinna denna begränsning utvecklades ett ramverk för beslutsstöd baserat på en integration mellan Non-dominated sorting genetic algorithm-II (NSGA-II) som en optimeringsalgoritm och AHP. Styrkan och begränsningarna angående användningen av ramverket testades senare genom att användning i designprocessen. För att undersöka möjligheter med ramverket utvidgades användningen genom att använda det för att utvärdera andra detaljer på klimatskärmen d.v.s. fönster såväl som ytterväggar, tak- och golvkonstruktioner. Resultaten visar ramverkets förmåga att lösa svårigheter och hitta lämplig designalternativ. Emellertid tillåter ramverket endast analys av objektiva kriterier för visuell komfort, termisk komfort, energiförbrukning och livscykelkostnader. Att ta hänsyn till subjektiva frågor beror därför på arkitekternas kreativitet när de utformar fönster och solskydd.Det Beslutsstödjande ramverket kan användas av designteam eller av kundstöd hos ett företag som tillverkar fönster. En litteraturstudie genomfördes för att utvidga en Technology Acceptance Modell (TAM) och därmed undersöka om designteam eller kundstöd har viljan att använda ramverket i praktiken. Resultaten visade att organisatoriska, individuella, tekniska och miljömässiga egenskaper var de mest inflytelserika externa variablerna vid undersökning av användarnas acceptans av ramverket. Organisatoriska egenskaper inkluderade ledningens stöd, utbildning, organisationskultur och organisationsstorlek, medan individuella egenskaper innehöll användarnas tidigare kunskaper och erfarenheter. Teknologiska egenskaper omfattade informationskvalitet och systemkvalitet, samtidigt som miljökarakteristik omfattade uppfyllande av regler och konkurrenskraft.

The Energy Performance of Building Directive obligated all European countries to reduce the energy requirements of buildings while simultaneously improving indoor environment quality. Any such improvements not only enhance the health of the occupants and their productivity, but also provide further economic benefits at the national level. Accomplishing this task requires a method that allows building professionals to resolve conflicts between visual and thermal comfort, energy demands, and life‐cycle costs. To overcome these conflicts, this study exploits the incorporation of building information modelling (BIM), the design of experiments as an optimization algorithm, and the analytical hierarchy process (AHP) into a multi‐criteria decision‐ making method. Any such incorporation can (i) create constructive communication between building professionals, such as architects, engineers, and energy experts; (ii) allow the analysis of the performance of multiple construction solutions with respect to visual and thermal comfort, energy demand, and life‐cycle costs; and (iii) help to select a trade‐off solution, thereby making a suitable decision. Three types of energy‐efficient windows, and five types of ground floors, roofs, and external wall constructions were considered as optimization variables. The incorporation of several methods allowed the analysis of the performance of 375 construction solutions based on a combination of optimization variables, and helped to select a trade‐off solution. The results showed the strength of incorporation for analyzing big‐data through the intelligent use of BIM and a simulation in the field of the built environment, energy, and costs. However, when applying AHP, the results are strongly contingent on pairwise comparisons

Sweden passed legislation to achieve a target of net zero greenhouse gas emissions by the end of 2045. The Energy Performance of Building Directive further obliged European countries to ensure zero-energy building codes and improve the quality of indoor environments when buildings are renovated, as approximately 40% of total greenhouse gas emissions in Sweden are produced while heating buildings. Windows currently play a significant role in improving the quality of indoor environments and cutting total energy consumption, thereby reducing greenhouse gas emissions and mitigating environmental impact. Selecting a suitable window design is a complicated task compounded by two main difficulties: i) the availability of multiple window designs, each with a different glazing system, size, form and position; and ii) conflict between visual comfort, thermal comfort and energy consumption. Previous studies have primarily analysed a limited selection of window designs; however, analysing a wide variety of glazing systems, sizes, forms and positions will help resolve the abovementioned difficulties, thereby ensuring zero-energy building codes while improving the quality of an indoor environment. A multi-objective optimization was therefore completed to analyse the performance of a wide variety of window design variables and select suitable designs for an office room in Sweden. The results show the potential of multi-objective optimisation to resolve the difficulties of selecting suitable window designs.

The selection of the most appropriate window and blind design is a challenging task due to the existence of potential conflicts between visual comfort, thermal comfort, energy consumption and life cycle cost. Resolving these conflicts relies on a trade-off window and blind design. This research applied a decision-making framework to select a trade-off window and blind design for an office room in Sweden. The decision-making framework was developed based on integrating the non-dominated sorting genetic algorithm-II and the analytical hierarchy process. The first step in the application of the framework was to generate a model of the office room using EnergyPlus. Six types of window and four types of blind; an internal venetian blind, an internal roller curtain, an external venetian blind and an external overhang panel, were modelled in EnergyPlus. The second step was to run an optimisation using non-dominated sorting genetic algorithm-II. For this purpose, various window and blind design variables were specified in modeFRONTIER platform. The third and last step in the application of the decision-making framework was to select a trade-off window and blind design using analytical hierarchy process. The results show the strength of the decision-making framework in selecting a trade-off design, and thereby the ability to resolve conflicts through intelligent use of simulation in analyzing big-data in built environment, energy and cost sectors. Since, the computation and processing power for performing simulations is constantly increasing, architects and designers can exploit the decision-making framework and locate a trade-off design in a relatively short period of time.

Swedish government adopted national targets to reduce total energy consumption and mitigate environmental impacts. At this point, detached houses play an important role, since they account for a large share of dwelling stock in this country. The majority of these buildings are affected by technical deteriorations in building envelopes and heating, ventilation and air condition systems. Accordingly, there is a need for a deep renovation strategy, which covers both energy efficiency measures and economic issues. Additionally, a deep renovation can improve indoor climate, which contributes to the enhanced health and wellbeing. Thus, the aim of this study is to compare the efficiency of eight different renovation packages in reducing energy consumption and providing economic benefits in a detached house in Sweden. The renovation packages include 1) improving the U-value of building envelopes; 2) adding a heat recovery for ventilation system; 3) installing a ground source heat pomp for supporting heat demand and domestic hot water; 4) combination of renovation package 1 and 2; 5) combination of renovation package 1 and 3; 6) combination of renovation package 2 and 3; 7) combination of renovation package 1, 2 and 3; and 8) combination of renovation package 1, 2, 3 along with installing photovoltaic cells for producing electricity. The reduction in energy consumption was calculated in kWh/m². year for each renovation package, while the economic benefit was obtained by calculating the payback period during a lifespan of 50 years and internal rate of return with interest rates of 1%, 3% and 6%. The results indicate that renovation package 8 has the highest potential in reducing total energy consumption, while renovation package 3 is the most profitable solution since it provides the shortest payback period with the highest internal rate of return. The results help to define and project efficient energy policies in Sweden.