Canada, Belgium, the United Kingdom and the United States: these are the names of the four residential buildings in La Faisanderie, built in 1952 by Marcel Lods, associated with his colleague Maurice Cammas, for the North Atlantic Treaty Organization (NATO) command in Europe. After being abandoned by NATO when France left the organization (1966), then by the French gendarmerie La Faisanderie was finally bought by a social housing body (HLM) and has just been restored. In addition to patient façade restoration work, the old military apartments were transformed into social lodgings for first time home buyers. Given the optimisation carried out by Marcel Lods on the fully pre-fabricated primary structure an analysis of the capacity of the existing structure was carried out from the foundations to the roof to confirm that it was possible to keep the entire structure. A real fire analysis of the concrete structure in a confined environment carried out with Efectis completed this investigation work.