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.

Hannover, the capital of the German federal state of Lower Saxony, has had a focus on energy efficiency since at least the mid-1990s when it approved a local climate protection programme. Energy efficiency of buildings has already been a key consideration as around half of Hannover´s housing stock was built in the 1950s and 1960s to low energy retention standards. Hannover thus began to explore ways of financing modernization and retrofitting of buildings, and installing renewable energy capacity, such as solar water heating.