Many cities have urban fabric ripe for renewal. Ajaccio, the regional capital of Corsica, is no exception. Taking buildings from the 1960s and making them more energy efficient is one of the main challenges being tackled by this Concerto-Project. An added challenge is the renovation of buildings in Ajaccio's historic centre. Double-glazing with thermo-coating is being installed in fifty buildings in the protected city centre. These buildings are among 250 being re-glazed in this way.