Simple Question, Complex Answer Pathways Towards a 50% Decrease in Building Energy Use

Sammanfattning: Addressing building energy use is a pressing issue for building sector decisionmakers across Europe. In Sweden, some regions have adopted a target of reducingenergy use in buildings by 50% until 2050. However, building codes currently donot support as ambitious objectives as these, and novel approaches to addressingenergy use in buildings from a regional perspective are called for. The purpose ofthis licentiate thesis was to provide a deeper understanding of most relevant issueswith regard to energy use in buildings from a broad perspective and to suggestpathways towards reaching the long-term savings objective. Current trends inbuilding sector structure and energy use point to detached houses constructed before1981 playing a key role in the energy transition, especially in the rural areas ofSweden. In the Swedish county of Dalarna, which was used as a study area in thisthesis, these houses account for almost 70% of the residential heating demand.Building energy simulations of eight sample houses from county show that there isconsiderable techno-economic potential for energy savings in these houses, but notquite enough to reach the 50% savings objective. Two case studies from ruralSweden show that savings well beyond 50% are achievable, both when access tocapital and use of high technology are granted and when they are not. However, on abroader scale both direct and indirect rebound effects will have to be expected,which calls for more refined approaches to energy savings. Furthermore, researchhas shown that the techno-economic potential is in fact never realised, not even inthe most well-designed intervention programmes, due to the inherent complexity ofhuman behaviour with respect to energy use. This is not taken account of in neithercurrent nor previous Swedish energy use legislation. Therefore an approach thatconsiders the technical prerequisites, economic aspects and the perspective of themany home owners, based on Community-Based Social Marketing methodology, issuggested as a way forward towards reaching the energy savings target.