The effect of considering the real consumption on the assessment of the renovation of social housing buildings

Abstract

Social housing is a priority within the European Union (EU) for boosting the necessary building renovation. The predicted and real consumption of buildings usually differ, and this is the Energy Performance Gap (EPG). Here, the effect the EPG has on the renovation decision-making process is analysed. The results show that a significant error in energy consumption reduction can occur if real consumption is not considered. Generally, it has been found that the average difference between considering real consumption or not is 22 percentage points. The economic perspective of the renovation is therefore influenced by the tenants’ real consumption and some renovation scenarios can become non-profitable or vice-versa. However, considering real consumption is complex and time consuming, so a simplified methodology intended for use by investors or administrators without considerable effort is proposed. This methodology has been proved to be reliable, accounts for real consumption, and allows a more accurate assessment of building renovation. Particularly, when real consumption is considered, the actual contribution of the building’s renovation regarding CO2 emissions reduction targets can be properly assessed. Finally, the improvement in the dwellings’ indoor conditions is analysed, as a key additional aspect to support the EU priority to renovate social housing.