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 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.

Sweden has an ambitious target to attain 50% more efficient energy use by 2030. Improving the energy performance of buildings provides a great opportunity to achieve the above-mentioned target. At this point, windows play a substantial role in improving indoor environmental quality and reducing energy consumption and cost. A computer-based system was therefore developed, which allows selecting a suitable window design. The computer-based system was intended to be used in a large-sized window and door manufacturing company in Sweden. However, the benefits of implementing the computer-based system cannot be realized until users accept using it. Former literature employed the technology acceptance model to investigate the influence of external variables on cognitive beliefs and trace their effects on users’ intention and actual system use. A successful application of TAM relies on the specification of the external variable. Accordingly, this paper conducted a systematic literature review to determine the external variable, affecting users' acceptance, thereby extended TAM. The analyses of results showed that organizational, individual, technological and environmental characteristics were the most influential external variables when investigating determinants of users' acceptance toward a computer-based system. Organizational characteristics contained mainly top management support, training, organizational culture, and organizational size, while individual characteristics embraced users’ previous knowledge and experience. Technological characteristics comprised information quality and system quality, meanwhile environmental characteristics included fulfillment of regulations and competitiveness. The extended TAM overcomes limitations attributed to the unified theory of acceptance and use of technology model since it considers attitude as direct determinants of intentions. In addition, the extended TAM is advantageous when compared with technology, organization, environment framework, because it has clear constructs, which allows tracing the influence of external variables on cognitive beliefs, and thereby their effects on users’ intention and actual system use. The extended TAM will be used to investigate determinants of users’ acceptance of the computer-based system in the manufacturing company in Sweden and compare the effect of external variables on users' acceptance.

Windows and blinds play a significant role in both shaping energy consumption and enhancing indoor comfort. But there are still difficulties with selecting windows and blinds due to the existence of potential conflicts between visual comfort, thermal comfort, energy consumption and life cycle cost. A literature review was conducted with the purpose of developing a decision-making framework that resolves the conflicts, and allows selecting a window and blind design based on trade-off between visual comfort, thermal comfort, energy consumption and life cycle cost. The decision-making framework was developed by integrating non-dominated sorting genetic algorithm-II as an optimisation algorithm with analytical hierarchy process as a multi-criteria decision-making method. The optimisation algorithm considers different window and blind design variables and analyses multiple designs, while the multi-criteria decision-making method ranks the optimization results and selects a trade-off design. An operating package enabled the decision-making framework to be automated. The operating package was obtained by coupling EnergyPlus as a simulation tool and modeFRONTIER as an integration platform. The decision-making framework was developed to select a trade-off window and blind design through intelligent use of simulation in analysing big-data in built environment, energy and cost sectors. Application of the framework ensures the minimum visual and thermal comfort thresholds with the lowest energy demand and cost. Architects and designers can use the framework during the design or renovation phase of residential and commercial buildings.

By covering interiors, such as walls, ceilings and floors, with wooden surfaces, one can change the quality of indoor environments and thereby affect both psychological and physiological responses. Psychological responses refer to individuals’ emotional reactions toward interiors, while physiological responses include changes in the activity of the brain, the autonomic nervous system, the endocrine system, and the immune system. The above-mentioned responses considered in this study are those caused by visual, auditory, olfactory and tactile stimulation from interior wooden surfaces. Although earlier studies have presented valuable information on this subject, questions remain about the material properties of wood which are associated with the stimulation. Specifying the material properties can support architects, designers and engineers who intend to use wood in interiors for improving psychological and physiological responses. A literature study therefore has been conducted to determine (i) the material properties of wood which are associated with sensory stimulation, and (ii) to specify relevant recommendations or requirements which should be fulfilled when covering interiors with wooden surfaces. The results show a lack of knowledge regarding the material properties of wood and the degree in which it affects sensory stimulation.

The majority of single-family houses in Sweden are affected by deteriorations in building envelopes as well as heating, ventilation and air conditioning systems, since they are about 30 years old. Theses house are therefore in need of extensive renovation, which provides an excellent opportunity to incorporate energy efficiency measures to reduce both the energy consumption and also operational. Although former studies analyzed the cost effectiveness of various renovation packages, they mainly excluded the evaluation of energy price implications on cost effectiveness of different renovation package in Sweden. Accordingly, this study considers three energy prices and quantifies the payback period (PBP) and internal rate of return (IRR) of the packages, when renovating a single-family house in Sweden. The renovation packages included three distinct energy supply systems, commonly installed when implementing energy renovations: ground source heat pump (GSHP), photovoltaic solar panels (PV), and an integrated GSHP and PV system. The analyses of results show that a the GSHP system provides higher IRR and the lowest PBP compared to the other two renovation packages, due to its high performance in reducing energy consumption and its relatively low investment cost. Furthermore, results show that raising the energy price can increase the IRR and reduce the PBP of the renovation packages and respectively. Moreover, increasing the interest rate adds on PBP of renovation packages, since it depreciates the cost for saved energy.