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The cost-optimal level of energy performance for buildings shall be identified according to the European directive of 2010. The Swedish building stock needs comprehensive knowledge and an overall strategy for the cost-optimal level of renovation. This paper studies the contribution of Swedish climate zones to the cost-optimal level of renovation on a multi-story residential building in Sweden from the building owner perspective. The building space heat demand is simulated for four Swedish climate zones. The net present profit (NPP) method is defined and used in this study in order to analyze the cost-optimal level and the cost-effective renovation of building envelope components (e.g., attic floor, basement walls, exterior walls and windows). The implication of different discount rates is studied, as well. The results show that the optimum renovation of the building envelope offers 51% more energy savings for space heating when the building is in a northern climate zone compared to a southern zone. The study suggests that different renovation strategies for the building stock renovation need to be identified, separately, for each climate zone. The NPP analysis identifies the minimum required investment and maximum achievable energy savings that are needed to have a cost-effective renovation. The broad range of studied climate zones provides the opportunity to apply the obtained results to other climate zones by either interpolation or extrapolation of NPPs for the buildings with similar characteristics. [ABSTRACT FROM AUTHOR]

In order to tap the energy saving and climate mitigation potential of buildings, transaction costs of implementing energy efficient technologies need to be better understood and ultimately reduced. The objective of this paper is to identify and analyze the nature and scale of transaction costs resulting from the application of the passive house concept in energy efficient renovations. Related conceptual choices are also discussed. This study explores learning strategies as a potential to reduce transaction costs. It focuses on transaction costs borne by building owners and building developers in the planning and implementation phases of a passive house-oriented renovation in Sweden. Results reveal three main sources of transaction costs: due diligence, negotiations and monitoring. The analysis shows that transaction costs are non-negligible and for individual cost sources the scale can be three times higher than for conventional renovations. To reduce transaction costs, various learning strategies such as study visits, demonstration projects, new forms of meetings and new channels of (written) information were found. These strategies have the potential to half transaction costs of future renovation projects. [ABSTRACT FROM AUTHOR]

Rapidly growing energy use in the building sector is considered a serious problem by both the European Union (EU) and Sweden. Reducing energy demand in the building sector is important for Sweden in order to reach national energy goals for reduced energy use and CO 2 emissions in the future. This project aims to find energy efficiency potential in multifamily buildings in the Gävleborg region, which is a cold climate region in Sweden. Measurements and simulations have been made on eleven multifamily buildings from the whole region. The results include different energy efficiency measure packages, profitability analysis of individual measures and packages, and primary energy use analysis. The paper also includes CO 2 emissions reduction analysis based on different methods. The project shows that the multifamily buildings in the Gävleborg region have good potential to reduce their energy use by more than 50%, which in turn will contribute to 43% primary energy reduction and 48% CO 2 emissions reduction. [ABSTRACT FROM AUTHOR]

Abstract: This paper presents the Energy, Carbon and Cost Assessment for Building Stocks (ECCABS) model, which is a bottom-up model to assess energy-saving measures (ESM) and carbon dioxide (CO2) mitigation strategies in building stocks. The model is based on a one-zone hourly heat balance that calculates the net energy demand for a number of buildings representative of the building stock and an additional code for the input and output data. The model generates results in terms of net and delivered energy, associated CO2 emissions, and the costs of implementing different ESM. The results are extended to the entire building stock by means of weighting factors. Empirical and comparative validations of the heat-balance modelling of single buildings are presented. The building stock modelling is validated against the current Swedish residential stock, for which the results of the modelling are in agreement with the statistical data. Using the model to assess a number of ESM reveals that the energy usage of the Swedish residential sector can be reduced by 55% and the associated CO2 emissions can be reduced by 63%, with most of the ESM being cost–effective. The applicability of the model to countries other than Sweden is under investigation. [Copyright &y& Elsevier]