Renovation of Swedish single-family houses from the 1960s and 1970s to net-zero energy buildings : Case study

This paper evaluates whether a net-zero energy building (NZEB) can be attained by implementing on-site renewable electricity production when renovating to Passive House level. The assessment is based on the Swedish single-family housing stock constructed between 1961 and 1980, using two case study houses and three locations. Specific conditions of the houses, such as the type of heat generation and available roof area for installation of a photovoltaic system, determine whether a NZEB renovation is possible. Overall, the assessment showed that it is not cost-effective to aim for NZEB when implementing a PV system, based on the alternatives in this study.