The extension and restructuring of the Quingey College is an opportunity for the Doubs Department to rapidly and sustainably improve the energy performance of this building by demonstrating its willingness to contribute to sustainable development while reducing operating costs. Indeed, on the latter point, although seeing almost double its surface area, the college will be able to see a significant decrease in its energy bill. This is made possible by a thorough restructuring of the external building: completely removed and partially demolished, it will be insulated according to the latest regulations, with the complete replacement of the roof and the addition of external thermal insulation in facades, all coupled with a double flow VMC and a new heating distribution network connected to a wood pellet boiler. This wood boiler, already operational in the new building, has been sized to quickly heat these two buildings and has been designed to address any risk of malfunction, thanks to its 4 modules independent of each other that can either work alternately or simultaneously when necessary. The new extension building meets the standards of the future RE 2020 and is currently being labelled E+C-: the E3C1 level currently being obtained is the second best level of the label, thanks to which the Department demonstrates its commitment to contribute to sustainable development.