In 1938, the Ateliers Jean Prouvé patented a “demountable metal-frame structure” using a module 8 meters (26.2 feet) square. The size was based on the capacity of the big bending press in the workshop, which machined 4-meter sheets of steel. This technical given meant a minimum area of 64 square meters (689 square feet) per module: a living space acceptable both to the occupants and to the constructor with their interests at heart.
In 1944–45, after meticulous transposition of Prouvé’s construction methods to family housing, a number of the 8×8 Demountable Houses were produced, with improvements aimed at greater comfort. The load-bearing structure was made entirely of bent sheet steel, as were the floor joists and the roof, unusually made of slabs. The use of this model for definitive reconstruction led to the manufacture of the Metropole house in 1949.