THE HIGHWAYS in and out of Nancy, in northeastern France, have seen some unusual traffic lately. Caravans of flatbed trucks stacked high with plywood crates have been rumbling through town, discreetly labeled and sealed. Antiquities? High-end audio systems? Cases of single-malt scotch?

Houses, actually. Nancy happens to be the hometown and onetime headquarters of Jean Prouvé, the late metalworker and self-taught architect and engineer who pioneered prefabricated construction, beginning in the 1930s. At his Ateliers Jean Prouvé,...