Buyers wonder if their homes are habitable at 35°C: how repeated heat waves have reshaped real‑estate buying criteria

Tested by the scorching summer, Sophia went to knock on the doors of agencies: she wants to sell her 1950s house, purchased and renovated barely eighteen months ago, in Livry-Gargan (Seine-Saint-Denis). Her two daughters, who were sleeping in the attic, although insulated, were so hot that the whole family went down to spend their nights on the ground floor. But how to sell a “thermal kettle”?

After seeing the market freeze, real estate agents are observing this fall “a change among buyers, who are wondering if their home is habitable at 35 degrees,” notes Valérie Parracone, of the Era Immobilier Montreuil agency. The smallest details are scrutinized: goodbye, single-oriented properties, facing south-west, without shutters, on a concrete courtyard... Rooms to the north, accommodation that can be ventilated and even the ground floors, "naturally cool", are popular. Without forgetting the gardens or air conditioning – 10% of properties are equipped.

Faced with the risk of a heatwave, how can we adapt our homes without air conditioning everything?

To support demand, real estate platforms are refining their services: SeLoger allows you to carry out your search by entering your own criteria (“summer fees”, for example); Well here, to simulate the sunshine of a home according to its orientation; PAP even noted summer comfort: +15% for reversible air conditioning, +5 to 10% for shutters. But there is no official scale yet, like the one used to adjust a real estate estimate, for example - 5 to - 10% for housing that is poorly laid out, noisy, dark, overlooked, etc.

Buyers looking for “safe havens” on the northwest coast of the country

The most likely, however, is that thermal kettles will end up, due to lack of purchase offers, ending up mechanically devalued, "like goods classified DPE F or G, which lose at least 15% compared to a DPE D", explains Thomas Lefebvre, scientific director of SeLoger. Example: in Paris, in the 17th century, a 2-room apartment of 50 m2, under the roof, was sold for 380,000 euros, although it had been put up for sale at 490,000 euros at the start of 2026.

To get your bearings better, a reform of the DPE, which currently only allows summer comfort to be appreciated through pictograms, would be in the pipeline. Taken by the emergency, the Minister of Housing, Vincent Jeanbrun, encouraged the installation of shutters and reversible heat pumps in condominiums, even Haussmann-style ones. “For the first time, we are looking at the quality of buildings based on the heatwave, rather than the cold,” confirms Henri Busy-Cazaux, president of the Institute of Real Estate Services Management.

Machine-translated from French