The Unités d’Habitation designed by Le Corbusier and André Wogenscky represent an exceptional moment in the development of the culture of housing in the 20th century1. Five examples of them were built – at Marseilles (1945-1952), Rezé (1948-1955), Berlin (1957-1958), Briey-en-Forêt (1953- 1961) and Firminy (1959-1967) – and they embodied a remarkable number of technical, constructional, typological, architectural and urbanistic inventions (pilotis, roof terraces, duplex apartments, fitted kitchens, rubbish chutes, brisesoleils, béton brut, etc.). They were the culmination of a long and patient reflection on housing and the outcome of a skilful combination of the individual and collective dimensions of dwelling. While the commissions for this new type of building continued for only fifteen years, they do not constitute a series of replicas of a prototype, but constructional systems specific to each development. In the course of their short lifespan, these differences would further be blamed for the process of inevitable erosion and its necessary repairs as well as for the changes, sometimes violent, that they were subjected to, closely connected with their micro-histories and the reception they received. We will examine the permanence of the image of the Unité d’Habitation suspended outside of time, and the differences in the realisations of the model, especially in their construction systems, on the one hand, and the transformations and degradations of their physical embodiments on the other.