In 1940, tenants were forced to leave,[4] as the building was requisitioned as the headquarters of the occupying German army during the Second World War.[5] In September 1944, after the liberation of Brussels, the building was taken over as headquarters for the Supreme Headquarters Allied Expeditionary Force (SHAEF) and the RAF Second Tactical Air Force.[6] After the war, in 1947, the Belgian Government bought the complex and used Bloc A (the north-eastern L-shaped building) for administrative offices.[7] At the end of the 1960s, as part of work to modernise the area during the construction of an underground railway line beneath the Rue de la Loi/Wetstraat, a new aluminium facade was built, closing the L-shape, under the supervision of Michel Polak's sons.