Séminaire des doctorants : Qiqi Tao (PhD Student at LMD)

PhD students seminar: Qiqi Tao (LMD)

Uncertainty of retrofitting scenarios in France based on building ages due to energy performance gap

Qiqi Tao (PhD Student at LMD)


France introduced its first thermal performance regulations in 1974 (RT1974), with the aim of reducing energy consumption by 25% compared with older housing. This was followed by a new regulation in 1982 (RT1982), aimed at reducing energy consumption by 20% compared with RT1974. Then came RT2005, with the aim of reducing energy consumption by a further 15%. We’d like to know whether these regulations have really contributed to the decarbonization of the residential sector, particularly in terms of renovation performance. To this end, a modified linear temperature sensitivity model based on the previous study is used, including construction age variables, so that temperature-sensitive consumption per group of construction periods is estimated for each administrative region. These temperature-sensitive consumptions estimated on the basis of actual consumption are dominated by heating and can be compared with the theoretical heating consumption estimated by the standard calculation of the energy performance certificate (EPC). The comparison reveals a clear difference between actual and conventional consumption, also known as the energy performance gap. However, our results show that for most administrative regions, thermal performance is not improved by implementation of the RT1974 and RT2005 thermal regulations as expected. The expected gain from renovation using conventional calculation is around 60%, if all buildings are to have the same thermal performance as new buildings constructed after 2006. But with our results, over 30% of buildings will consume more than before renovation, which will be problematic for the net-zero target.

Skip to content