In 1940, the Château d'Argenteuil, 20 hectares of its surrounding lands and a farm were sold to a community of Carmelite Sisters in exchange for their properties in Uccle, Brussels. However, the château was not suited to their needs, and they moved out in 1947. The Belgian government acquired the Château d'Argenteuil in 1949. In 1950, as part of preparations for the 1958 Brussels World’s Fair, the Belgian government used the chateau to relocate the French-speaking section of the "", an all-female normal school, from Laeken, the site of the exhibition. The château's bedrooms were refitted for boarders. The Belgian government later used the site for various Belgian state school establishments, building dedicated buildings for classrooms on the grounds of the château. In 1990, the Scandinavian School of Brussels, Queen Astrid School, purchased the Château d'Argenteuil and its grounds, and relocated there in 1992. From September 2016, the European School of Bruxelles-Argenteuil began operating on the same site.