The City of Bastia has decided to implement a project aimed at urban restructuring, economic revitalisation and social cohesion on the Old Centre. This case concerns the energy rehabilitation operation of the Gaudin School: overlooking the City of Bastia, it is an old building (SHON 1 936 m²), located on five levels. The energy rehabilitation project was selected under a CAB ITI PAA: Energy rehabilitation concerns insulation (walls, low floors, roofing, changing openings), volume management (installation of a false ceiling), installation of a double flow VMC, LED lighting and efficient heating and air conditioning (VRV reversible air heat pump). The target energy level is 34.46 kWh of primary energy, per m² SHON, a 73 % decrease from the reference consumption (above the 40 % minimum required by the BBC renovation). The total regulatory gain in primary energy compared to the initial is 219 426 kWh per year, i.e. – 76 % compared to the initial, or still 18 % of the objectives of the investment priority corresponding to the CO32 indicator. As regards the investment priority “reducing greenhouse gas emissions” (CO34 indicator), the reduction is more than 60 tCO2eq per year, i.e. 12 % of the targets. Thus the project fully meets the objectives of the 4c of the ERDF OP Corsica