A result of a close collaboration between Jean Prouvé and architect Pierre Jeanneret, the construction site for the SCAL factory in Issoire represents a significant step in the History of modern architecture. This major project, initiated in a context of war, will allow for a demonstration of a construction prefabricated in the plant and subsequently dry-mounted on site. Jean Prouvé will also use his axial portal frame constructive system for the very first time. These avant-garde solutions – practical, economical but also aesthetically pleasing – will retain the attention of the authorities in charge of the postwar construction.