8x8 Demountable house, 1944
Continuing his research into demountable houses, in 1938 Jean Prouvé came up with the structural principle of the axial portal frame, which he patented the following year. He decided to apply it via a module 8 meters (26.2 ft) wide: a size based on the capacity of the big bending press in his workshop, which machined 4-meter sheets of steel to produce the components for house frames and envelopes. This technical given meant a minimum area of 64 square meters (689 square feet) per module, offering a living space acceptable to both the occupant and the constructor with the occupant’s interests at heart. Early in the War Pierre Jeanneret applied the method to a project for lightweight buildings; thus did the Le Corbusier workshop abandon the Modulor for the Prouvé grid. Incorporating variations on the portal frame structure, these one and two-story buildings betray an adaptation to the shortage of metal that found its culmination in the engineers’ houses, made entirely of wood. In 1944–45 the need for temporary buildings gave the Ateliers Jean Prouvé the chance to employ the portal frame for houses for people left homeless by the War. At the same time, though, the Ministry of Reconstruction and Town Planning (MRU) reduced the grid to 6 meters (19.6 ft). A number of 8 x 8 meter (26.2 x 26.2 ft) houses were nonetheless produced as part of an urgent reconstruction operation headed by architects Jacques and Michel André. Not to be confused with the MRU order, this project had permits for larger quantities of metal, at the time subject to strict quotas. The load-bearing structure, using a specially redesigned portal frame, was made entirely of bent sheet steel, as were the floor joists and the roof, unusually made of slabs. This made clear the model’s potential for permanent dwellings, but it was only after several fruitless experiments and numerous studies and prototypes that in 1949 Jean Prouvé was finally able to begin manufacturing his Métropole house: light, economical and comfortable, entirely made of steel and aluminum, and based on an 8 meter (26.2 ft) grid.