Abstract for: Misconceptions of the Dynamic Nature of Building Energy Retrofitting Rates in Germany
A large proportion of the fossil energy consumption and CO2-emissions in Germany is due to heating of buildings. Building energy retrofits have been proposed as one of the most cost-effective and high-leverage ways to reduce fossil energy consumption and CO2-emissions in Germany. Accordingly, the federal German government declared increasing the building energy retrofitting rates as being a key priority in their long-term Energy Concept. A close look at governmental targets as well as some of the research on building energy retrofits reveals a misconception on the dynamic nature of retrofitting rates: they are assumed to constant instead of exponentially decreasing. This is a result from these rates being commonly defined relative to the whole stock of buildings instead of the stock of buildings in need of retrofit. The overestimation of future retrofitting rates that results from this misconception casts serious doubt on a suggested keystone of the German Energy Transition.