Estimating the influence of rebound effects on the energy-saving potential in building stocks

The energy-saving potential in buildings (e.g. buildings proposed for an energy upgrade in an energy policy context) is often overestimated because implicit factors, such as rebound effects, are ignored. In order to get an accurate estimate of the realisable energy-saving potential in a building stock, these factors, as well as how they differ among buildings with different characteristics, must be accounted for. On the building stock level, detailed information about the actual conditions in each building (e.g. indoor temperatures, domestic hot water consumption, internal heat loads, etc.) is rarely available. In its place, fixed assumptions are often made, usually disregarding the characteristics of the buildings. Therefore, a method that is based on available building stock data is needed for adjusting this technical energy-saving potential. This study investigated how the heat consumption in residential buildings might be expected to change due to an energy upgrade, using a hybrid bottom-up model of the Danish residential building stock. Pseudo-rebound effects, inherent to the thermal standard of the building, were quantified in a sample of 134.000 buildings with different characteristics. Results showed that estimating the heat-saving potential on the basis of the thermal characteristics alone (i.e. the technical heat-saving potential), would lead to a considerable overestimation of the realisable heat-saving potential in the residential building stock. However, the size of the realisable heat-saving potential was found to vary considerably among buildings with different characteristics, despite having the same technical potential. This indicated that the technical heat-saving potential should be corrected differently in buildings with different characteristics.