The Community of Communes Terre de Picardie wanted to be an exemplary community in improving the energy efficiency of its existing buildings by transforming them into "sustainable buildings". The work carried out makes it possible, while improving the quality of life and the health of users, to control the impacts on the environment, to ensure optimal energy performance, while using bio-based materials, using the reuse of materials and using renewable energies. This project makes it possible to transform an energy-intensive building into an energy-producing building. This project makes it possible to divide greenhouse gas emissions by three.