The operation concerns the mainly energy rehabilitation of 40 housing units in Pont à Mousson concerning 2 buildings, Rossignol and Chardonneret located rue du bois le Priêtre in the summer of 2020. The aim of the work is to reduce the consumption of the building (to reach the level equivalent to the BBC (104 kWh/m².year)), to improve the safety and comfort of the inhabitants. The renovations concern the following items: — work aimed at a certain energy performance (insulation, technical equipment, replacement of carpentry, etc.); — works related to the fire safety of buildings (smoking, fire-resistant rooms, etc.); — rehabilitation works inside the dwellings and in the common areas (sanitary facilities, rehabilitation of entrance halls, etc.). — architectural improvements and layout of outdoor spaces: Treatment of facades, valorisation of entrances, renovation of outdoor spaces in order to enhance the image of buildings and of the district by working on the overall aesthetic – Electrical safety: it concerns the electrical safety of dwellings and common areas