Energy renovation: the challenge of small co-ownerships built before 1940

Renovating a condominium "is difficult, it takes time and money," says Jean-Marie Guerout, president of the board of directors of a condominium of 439 housing units in the north of Paris, who improved its energy performance by 42% by insulating the walls, roof, windows and modifying the heating system.

He convinced the other co-owners with the argument of a reduction in energy bills and especially because thanks to public aid, the additional cost compared to simple facade renovation work was low. State and local authority aid generally covers 30% to 40% of the bill.

Mr. Guerout's residence dates from 1970, and "all over France, post-World War II buildings have undergone massive renovation", because these are "fairly easy" jobs, says Sébastien Catté-Wagner, a specialist in decent and sustainable housing at the National Housing Agency (Anah), which distributes aid for energy renovation, including Ma Prime Rénov' Copro.

The problem is mainly "old town centres, where the co-ownerships are smaller" and where "the cost per co-owner is high" for major renovation work, he explains.

On the CoachCopro website, the support platform developed by the Paris Climate Agency, examples of energy renovation of old buildings are still very rare.

Among those presented, an eight-unit building, built in 1900 and located in the center of Paris: work began in 2021 to, in particular, insulate its roof, change the windows and the collective boiler. The total cost of the renovations reached 44.400 euros per dwelling - more than double that of Mr. Guerout's building - and all for an energy gain of 32%.

Protected facades

But as with many buildings, the possibilities for insulation were constrained by the preservation of heritage.

Yann Sayaret, Orpi partner and head of a real estate agency in Le Havre which offers condominium syndicate services, testifies: "the city of Le Havre is classified as a UNESCO world heritage site, so we don't touch the facades and external thermal insulation (ITE) is to be forgotten."

"Without an ITE, we know that energy renovation is less effective and if we cannot achieve the 35% energy gain that allows us to unlock aid, we are at an impasse and the projects are abandoned," he explains.

It is for this type of building that Anah has launched an experiment called MaPrimeRénov' Petites copro: for co-ownerships of up to 20 dwellings, subsidies can be released from 15% energy gain thanks to the work, explaining why it is impossible to reach the 35% threshold.

Yann Sayaret also highlights the need for a return on investment: "If you tell owners who are 60 or 70 years old that they are not going to get their investment back, their interest is reduced."

All the more so for low-income households who will find it difficult to cope with an investment of several thousand euros.

Anah seeks to avoid these situations and especially to prevent co-owners from being forced to sell their homes because of renovations. Individual aid of 1.500 to 3.000 euros can, for example, be released.

But for Jacques Baudrier, the deputy mayor of Paris responsible for housing, the ceiling of 25.000 euros per dwelling for aid granted by Anah must be raised.

"Two thirds of Parisian housing was built before 1945, we have a lot of trouble taking on these buildings" where the costs of energy renovation can rise to "80.000 or 100.000 euros per dwelling", says the PCF elected official.

However, constrained by a high public deficit, the government has decided to reduce MaPrimeRénov' subsidies in its 2025 budget project, to 2,3 billion euros, compared to 4 billion announced for 2024.

Illustrative image of the article via Depositphotos.com.