The exhibition “Édifices” of 1968 at the Musée des Arts Décoratifs displaced the “imaginary architectures that are not real architecture but rather images constituted as housing”. In the midst of the Hourloupe series, Dubuffet discovered a new material, expanded polystyrene, that he sculpted with a hot wire, abandoning the space of the painting for sculpture and then architecture. The works are created without a specific destination, as Dubuffet did not really envisage their construction. But to activate the imagination of visitors to the exhibition, the demonstration was made through the intermediary of photomontage, integrating simulacra of architectures in a very real urban fabric. The artist nevertheless had the opportunity to confront his pure mental projects with the more real process of construction by using the pantograph, “the machine for enlarging”. This is how several sculptures were executed during his lifetime after his models and projects, both in France and abroad, and are still today following the artist’s desire.