A questionnaire survey of 1010 homeowners in Jämtland and Västernorrland, which are two counties in central Sweden, was conducted to understand the factors influencing their decision to install energy-efficient windows. We complemented this survey with an interview of 12 window sellers/installers in the county Jämtland. The annual energy cost reduction, age, and condition of the windows were the most important reasons for the window replacement decision. Approximately 80% of the respondents replaced their windows with energy-efficient windows with U-value of 1.2 W/m² K. Condensation problems, perceived higher prices, and lack of awareness about windows with lower U-values were important reasons for non-adoption of more energy-efficient windows. Window sellers/installers have a strong influence on homeowners’ window selection that was indicated by the 97% of homeowners who bought the windows that were recommended to them. Sellers/installers revealed that they did not recommend windows with U-value of less than 1.2 W/m² K because they thought that investing in such windows was not economical and because windows with U-value less than 1.2 W/m² K could cause water condensation on the external surface of window pane.

In Sweden, there is opportunity to implement energy efficiency measures in about one million existing apartments that are likely to be refurbished within the next 20 years. System analyses of installation of energy efficient windows, and increased insulation in attic and in exterior walls for an existing multi-story building showed that the primary energy savings for the measures depend on the energy supply system. Energy efficiency potential was higher with installation of efficient windows than improved attic insulation. Responses of 673 chairpersons of co-operative hosing associations to a mail-in survey in 2010 also showed that greater proportion of respondents perceived that energy efficient windows had advantages over insulation improvements. However, majority had no intention to implement such measures during next 10 years and economic factors guide their decisions. Lack of expertise to assess the benefits of energy efficiency measures was the most cited hindrances to energy efficiency investments.

External actors can influence potential adopters to adopt energy efficiency measures. In Sweden municipality energy advisers are one such actor group who provides energy advice and information to the end users. The success of energy advice service for improvement of energy efficiency of detached houses depends on homeowners' perception towards it. In this context, we conducted a national survey of about 3000 owners of detached houses through stratified random sampling method in the summer of 2008. We found that majority of owners of detached houses consider energy advisers as an important source of information. Furthermore, many homeowners who contacted energy advisers for advice had implemented the suggestions. However, only a few homeowners had contacted an energy adviser. Our findings suggest that it is beneficial to continue the energy advice service, but more efforts are needed to increase homeowners' awareness of and satisfaction with such services.

Municipality energy advice services were re-introduced in Sweden in 1998 as a way of advising end-users, mainly owners of detached houses, on energy issues. In this paper, we investigate Swedish energy advisers' perceptions of homeowners' awareness of the energy advice service and their perceived ability to fulfil homeowners' expectations. Our study is based on a mail-in questionnaire survey conducted in 2009 and distributed to municipality energy advisers in all municipalities in Sweden. About 66% of the energy advisers responded. The results show that 43% of the energy advisers thought that fewer than 50% of the homeowners were aware of the service and that mass media advertisements and presentations at different organisations could improve homeowner awareness. Energy adviser attitudes, job satisfaction, and the perception that the advisers possessed up-to-date and good knowledge and sufficient financial resources to execute their duties had a significant influence on their perceived ability to fulfil homeowner expectations. Increased training in technical aspects of energy measures and increased financial support were the two measures most widely suggested as a means to improve energy advisers' performance.

We used the data from a survey conducted in 2008 of 3,000 owners of detached houses to analyse the factors that influence the adoption of investment measures to improve the energy efficiency of their buildings. For the majority of Swedish homeowners, it was important to reduce their household energy use, and most of them undertook no-cost measures as compared to investment measures. Personal attributes such as income, education, age and contextual factors, including age of the house, thermal discomfort, past investment, and perceived energy cost, influence homeowners’ preference for a particular type of energy efficiency measure. The implications for promoting the implementation of energy efficiency investment measures are discussed.