Effects of thermal insulation on actual residential energy consumption

In France, the residential sector accounts for a quarter of final energy consumption. Energy renovation of housing is therefore a major focus of energy-saving policies. However, the actual energy savings achieved through renovation work remain poorly documented. This study evaluates the impact of thermal insulation work carried out in single-family homes on actual electricity and gas consumption, using data from smart meters (Linky, Gazpar). By analyzing quarterly consumption variations before and after the renovations, we estimate an average reduction of 5.4% in total electricity consumption for homes heated with electricity, and 8.9% for gas in homes heated with gas. These effects are heterogeneous: homes with high energy consumption before the renovations show greater savings—up to 16.6% for gas. However, these savings remain lower than those predicted by theoretical models, confirming the existence of an energy performance gap. Our results highlight the importance of accounting for behavioral and situational heterogeneity in order to better target public renovation policies.