Tours Aillaud Renovation, Nanterre

Nanterre’s cloud towers are getting stainless steel skins. The Tours Aillaud, 18 cylindrical towers designed by Émile Aillaud and finished in the 1970s at the edge of La Défense, hold about 1,600 apartments. Their glass-paste mosaics of sky and cloud, by Fabio Rieti, gave the estate its nickname, Tours Nuages. They’re also falling off, and the City of Nanterre says the towers lose around 40% of their heat through the envelope.

The Tours Aillaud renovation is the fix, and it’s a divisive one.

Project Scope

The estate splits three ways. Social landlords Nanterre Coop’ Habitat and Hauts-de-Seine Habitat keep 11 towers and 1,078 moderate-rent homes, which get new external insulation. Six towers go to developer Cogedim, working with Histoire & Patrimoine, for conversion to for-sale housing plus about 20,000 m² of activities and services, and those keep restored mosaics. One tower comes down.

The insulation system is the technical story. Architects Dominique Renaud and Philippe Vignaud of RVA, with designer Pierre di Sciullo and artist Amélie Lebleu, specified prefabricated stainless steel blocks, colored through the metal and backed with rock wool. They’re made at a plant in Alès, each about 2.6 m tall and formed to the tower’s curve. Citynox and Lucaria handle installation. The pilot, Tower 15, took about 5,000 m² of cladding and cost roughly €10 million.

Because the system isn’t covered by standard French technical rules, every step waits on approvals: CSTB certification for the new windows, and an ATEx experimental assessment with BTP Consultants as rapporteur. As of December 2025, towers 7, 11, 19 and 95 were waiting on that sign-off before work could start. Tenants stay in place while old windows are swapped from inside, though about 500 households have had to be rehoused during the program.

Why It Matters

Europe has thousands of 1970s social-housing towers with decorative envelopes that fall well short of current thermal rules. The usual answer is an EPS-and-render wrap that fixes the heat loss and erases the design. Nanterre is trying a middle path: a new skin that carries the original colors and patterning in steel. Critics see a replacement, not a restoration, and Le Moniteur has reported the project waiting on a clearer position from France’s culture ministry.

The money is public and private together, about €230 million across the estate, including €82 million from ANRU, the national urban renewal agency. The social-housing towers are due in early 2028. Everything else is targeted for 2030.

Project Team & Details