As the father of a large family, Prouvé was not drafted into the war and managed to keep his workshop afloat producing stoves, kilns, swings, and bikes. In 1939, Prouvé designed and patented the “axial portal frame,” his now well-known and highly collected/studied construction system for prefabricated housing. In light of wartime material restrictions and a scarcity of metals, Prouvé sought Jeanneret's expertise: the design of F 8x8 BCC House
utilizes Prouvé’s construction system, but the structure is comprised entirely of wood. "BCC" in the title of the house refers to "Bureau Central de Construction," which was the company where Prouvé, Jeanneret and Perriand worked together to develop non-permanent houses during the war.
In her memoir, Charlotte Perriand recalls the working relationship between Pierre Jeanneret and Jean Prouvé:
“During the occupation due to scarce materials and communication difficulties with the Jean Prouvé Workshops, Pierre decided, in early 1942 to substitute wood for steel in his prefab designs, a material he liked, without, however, breaking away from the Prouvé approach. Pierre loved sheet metal and the bent sheet metal technique that Jean had introduced him to. In exchange, he transmitted the love of wood to Prouvé, and more importantly the contribution of a field architect sensitive to structures, furnishing, the environment, plasticity, and ‘overall harmony.’”