LAUSR

Abstract Around 25% of final energy consumption in the European Union is currently used for space heating. The potential for reducing this demand through renovation of existing buildings is very significant and recognised to be an important factor for reaching CO2 reduction targets. In this analysis we develop two types of cost curves for heat savings in buildings in 6 European countries. This is based on a detailed representation of the existing building stocks and an analysis and comparison of costs and effects of refurbishment actions for several levels of heat savings in each representative building in these countries. We find that the costs for reaching savings of 40–60% are remarkably cheaper than for reaching higher savings and that the highest and cheapest savings are located in buildings that are still not renovated. We also find the following highly influencing factors on the costs of renovation measures: the share of window area in the envelope, the surface-to-volume ratio and the current heat demand. The results of this work can be further used to investigate cost optimal levels of heat savings versus heat supply in order to draw the right decisions on the way to an efficient and low CO2 energy system.