Addressing housing shortage through energy and space-efficient retrofitting: The case study of a Swedish Single-Family house

Abstract

Sweden's shortage of affordable housing has been evolving into a major in recent years. A 2021 report by the Swedish National Board of Housing, Building, and Planning (Boverket) stated a need for 60,000 new homes by 2030. In addition, the Swedish building stock is responsible for 39% of the country's total energy consumption and 21% of its greenhouse gas emissions. Therefore, solutions to address the housing crisis should go hand in hand with the need for increased building retrofits to meet Sweden's 2045 energy and climate targets. In this context, re-densification of the existing building stock is a possible option. This study examines possible space- and energy-efficient options for densifying the housing supply in Sweden's existing single-family home (SFH) segment. Using a case study in Kronoberg, Sweden, occupied by an elderly household, options for converting the unused space into new additional dwelling units (ADUs) and reducing per capita living space are explored. Most SFHs in Sweden are old, in poor condition, and in urgent need of structural and energy retrofits. In addition, about one- third of homeowners are over 60 years old and report living in homes that are too large compared to their needs - an excellent environment to study the proposed intervention. Revenues from renting the newly created ADUs suggest that the proposal is financially attractive because it capitalizes on the high initial investment costs of energy retrofits. In addition, spatial interventions combined with energy-efficient measures result in a 40 percent lower energy use and environmental impact per capita compared to energy retrofits alone due to a reduction in per capita living space. Finally, the study aims to initiate a discussion on sufficiency, innovative energy regulations, and housing policy tools needed to transition to the low-energy single-family housing stock.