Climate has become a factor in real estate purchases.
After a summer of heat waves and wildfires, one in five French people is considering moving. Summer comfort, clay soil, insurability: four things to check before signing a lease, using free public tools that almost no one uses.
The energy performance assessment has been evaluating summer comfort since 2021. Almost no one knows this, and for one simple reason: the indicator does not appear on the A-to-G color-coded label—the one featured in listings. It is relegated to page 2, in the form of a three-level pictogram: good, average, or poor.
The result is striking. According to an analysis of ADEME’s energy performance certificate (DPE) database conducted by Pouget Consultants and IGNES—published in June 2026 based on nearly nine million energy performance certificates—only one in ten homes has satisfactory summer comfort. About one in two is a “thermal kettle.” And one-third of homes rated A or B have insufficient summer comfort—in other words, they’re like upside-down sieves.
The indicator measures passive comfort—that is, the thermal mass of the building structure, whether the dwelling is a through-house, roof insulation, sunshades on windows and doors, and air circulators. Air conditioning is not included in the calculation. The primary factor contributing to overheating identified is the lack of exterior sunshades, which is the least expensive element to address.
On July 16, 2026, the Minister of Housing announced the creation of a label dedicated to summer comfort, which will be as visible as the energy label. No executive order has been issued to date.
Thirty Seconds on Géorisques
The Géorisques portal, published by the Ministry of Ecological Transition and the BRGM, allows you to enter an address and obtain a list of the risks to which it is exposed: flooding, wildfires, earthquakes, clay shrinkage and swelling, radon, contaminated sites, and classified facilities. It’s free and instant.
Disclosure is also mandatory. As of January 1, 2023, the seller or landlord must disclose information about risks in the real estate listing. The risk and pollution report, valid for six months, must be provided at the time of the first showing and then attached to both the preliminary sales agreement and the lease. In the event of intentional omission or false information, the buyer may ask the court to rescind the contract or reduce the price. Since 2025, additional obligations regarding brush clearing have been introduced for properties located within 200 meters of a high-risk forested area. It is worth noting that 90% of the homes destroyed by forest fires were on poorly cleared land.
Clay Soils: The Risk No One Is Paying Attention To
The shrinkage and swelling of clay soils cause cracks in single-family homes as the soil dries out and rehydrates. Although it receives little media coverage, the scale of the problem has just changed. A decree dated January 9, 2026—applicable to transactions concluded since July 1—has redrawn the risk map: 55% of mainland France is now classified as having moderate or high risk, up from 48% previously, and 12.1 million single-family homes are affected, representing 61.5% of the housing stock.
The cost is following the same trend. This risk accounts for 42% of claims paid out for natural disasters, with the total cost rising from approximately 375 million euros per year between 1995 and 2015 to nearly 1.5 billion euros between 2018 and 2022. The average claim amounts to 16,500 euros.
In areas with moderate or high risk, a preliminary geotechnical study is required before the sale of an undeveloped building lot. For an existing home, there is no such requirement. It is up to the buyer to request one.
What the price doesn’t yet reveal
The energy performance rating (DPE), on the other hand, is already reflected in prices. According to a study by Notaires de France on 2024 real estate transactions, a house rated G sells for 25% less than an equivalent house rated D, and one rated E sells for 9% less. For apartments, the range goes from +16% for Class A to −12% for Class G. Notaries have derived a rule of thumb from this: for every lower energy class, a house is worth about 8% less.
Climate risk, on the other hand, is very difficult to price. The only comprehensive public study—conducted by the ministry in 2015 on flood risk—explains why. The natural disaster insurance system is based on a uniform premium surcharge that is identical everywhere, regardless of the level of exposure. A high-risk property is therefore no more expensive to insure than a low-risk one, and the market does not factor the risk into the price. This surcharge increased from 12% to 20% as of January 1, 2025, which accounts for most of the 7.8% increase in home insurance premiums observed that same year, resulting in an average premium of €323 before taxes.
Buyers cannot, therefore, rely on the price to alert them to this risk. They must verify it themselves.
