Building renovation in shrinking and aging cities: a complex problem. A case based investigation
Thermal renovation (retrofit) of residential buildings is one of the major issues in the transition to a low-carbon energy system. This paper argues that the specific conditions in shrinking middle-size cities create an especially difficult environment for energy renovations. Using empirical data from the shrinking City of Delitzsch, Germany, it is hypothesized that buildings with poor energy efficiency are often inhabited by tenants or owners who impede retrofit activities due to their socio-economic conditions. The research analyzes the relation between buildings with a high potential for final energy reduction and a concentration of low-income, older or empty-nest households. The analysis examines this relation not only on an aggregated city level but also on the level of the city's districts to identify renovation ‘hot spots’ in the city. Specific challenges are identified for building renovations in shrinking cities due to a high concentration of possible barriers in the relevant housing stock. As a further consequence, those households with a low net-equivalent income are also at risk of energy poverty. In order to achieve a low-carbon and just society, possible actions are suggested for buildings with elevated barriers to energy renovation in shrinking cities.