Partenord Habitat thermally rehabilitates a heritage composed of a building built in the 1970s, considered as emblematic tower of the district of the lower town of Dunkirk by its height of 16 floors, and including 131 collective housing. The project consists in carrying out thermal insulation by the exterior, replacing the exterior joinery with PVC frames of high thermal performance, replacing the DHW network and collective heating. In addition, and to improve the living environment of tenants, it is also envisaged to replace all sanitary facilities, floors and entrance halls, and to carry out a residentialization in order to privatize the surroundings of the residence. The installation of electric terminals for vehicles is planned to modernize the parking lots and meet all needs. The objective of the rehabilitation is based on three actions: - treatment of the envelope, - common areas, - housing. The work will improve the energy label from D before work (229 kWh/m2/year and 37kg COeq/m2/year) to C after work (161kWh/m2/year and 26kg COeq/m2/year). .