The gap between real before and after renovation figures in condominiums

Benjamin Rougeyroles, expert in charge of the Energy retrofitting observatory at the Paris Climate Agency, explains how and why expected and achieved energy performance often differ. He presents ways to correct current renovation procedures in condominiums.

Within the ACE-Retrofitting project, the Paris Climate Agency has carried out a detailed audit of 8 condominiums (641 apartments) from December 2017 to December 2019. Its purpose being to measure a broad range of indicators (i.e. real energy consumption, air quality, indoor comfort, before and after retrofitting by installing 614 measurement points during two consecutive heating periods. A number of interesting points have been highlighted, especially the disappointing results for real energy savings.