What to do if your French home is cracking because of drought

More than 12 million houses in France sit on clay soil that shrinks in droughts and swells when the rain returns, and after one of the driest summers on record many owners are finding new cracks in their walls. Here’s what to do – and when.

Is it drought damage?

If there are cracks in your interior or exterior walls, or your doors and windows don’t close as easily as they used to, it could be due to retrait-gonflement des argiles (RGA).

Translated as ‘shrinkage and swelling of clays’, this phenomenon occurs when clay soil under the foundations of a building shrinks as the ground dries out and swells again when it gets wet.

The more this happens, the weaker the soil and the house built upon it become.

In more serious cases, floor slabs and partition walls can break up, buried water pipes can rupture and cracks can go right through the wall, so that they’re visible both inside and out.

To see whether your home is in a zone exposed to RGA, look up your address on the government’s Géorisques website.

What to do if you spot cracks

Before doing anything else, there are some simple steps to take that may help you further down the line:

1. Photograph and date every crack. Monitor walls inside and out, and keep taking photos as the cracks change. According to French insurance broker Leocare, a dated record of when the damage appeared and how it got worse can help prove it was caused by the drought.
2. Tell your mairie. Insurance only pays out for drought damage if your commune is officially recognised as a natural disaster zone (but even then, it’s not guaranteed), and it is the commune – not you – that applies for that. 
3. Let your insurer know. Submit a written déclaration de sinistre (claims notification) to your insurer as soon as you notice the damage – more on how to do this below.
4. Don’t rush into repairs. According to French media outlet Futura, repairing cracks yourself before your insurer’s expert has assessed them can make it harder to prove the drought caused them. If urgent work can’t wait – to make the house safe, for example – photograph and date the damage first, check with your insurer before starting, and follow the government’s advice to keep all your invoices.

If you rent your home, your landlord will no doubt appreciate it if you let them know about the cracks as soon as you notice them, and take dated photos of them. Your landlord can then submit an insurance claim, tell the mairie about the damage, and oversee any urgent repairs.

Cat nat recognition

Drought damage is covered by the catastrophe naturelle (cat nat) guarantee, which is automatically included in any home insurance policy covering damage to property.

But it only applies once an arrêté recognising a natural disaster in your commune has been published in the Journal officiel, a daily government publication containing new laws, decrees, and official orders.

It’s the commune’s job to apply for cat nat status – it generally has up to 24 months after the event to do so.

Once the commune has applied, the arrêté should normally be published within two months.

Check the details carefully when the arrêté is published. It must cover drought specifically – the official wording is mouvements de terrain différentiels consécutifs à la sécheresse et à la réhydratation des sols – and the right period.

How and when to submit an insurance claim

Once the arrêté is published, you have 30 days to declare the damage to your insurer.

If you’ve already declared it, your declaration still counts, but it’s worth writing again within those 30 days, enclosing a copy of the arrêté, so your insurer links it to your claim.

Send your claim by recorded letter, preferably with acknowledgement of receipt (lettre recommandée avec accusé de réception), to your insurer – the address is on your policy documents.

If your policy is managed through an agent or broker, the government advises sending them a copy too.

What to do if your claim is refused or the offer is too low

According to law firm Kohen Avocats, insurers often accept that the cracks exist but argue that drought wasn’t the primary cause – blaming construction defects, for example, or saying the cracks were already there.

If this happens, there are several steps you can take:

1. Get a second opinion. You can hire your own independent expert, known as an expert d’assuré, for a counter-assessment (contre-expertise). You usually pay for this yourself unless your policy includes cover for expert fees (garantie honoraires d’expert), so check your contract.
2. Bring in a third expert. If the two experts still disagree, a third expert can be chosen jointly by you and your insurer.
3. If you still can’t agree, complain, then mediate. Make a written complaint to your insurer. If that doesn’t resolve it, you can take the case to the insurance ombudsman (La Médiation de l’Assurance), and ultimately to court.

If you need help with any of these steps, there are several associations that help homeowners with drought claims, including the national groups Les Oubliés de la Canicule and Urgence Maisons Fissurées.

READ MORE: Taxe foncière: How to challenge your 2026 French property tax bills

Prevention is better than cure

If your house is still in good condition, or only slightly cracked, the state may help you protect it.

Since October 2025, an experimental fonds de prévention argile has been running in 11 départements: Allier, Alpes-de-Haute-Provence, Dordogne, Gers, Indre, Lot-et-Garonne, Meurthe-et-Moselle, Nord, Puy-de-Dôme, Tarn and Tarn-et-Garonne.

If you’re eligible, it could help pay for a ‘vulnerability diagnostic’ by an RGA specialist, including a check for leaks in buried water pipes, followed by preventive works.

Eligible works include laying or repairing rainwater drainage pipes, installing root barriers or removing roots too close to the house, and laying a waterproof membrane or a waterproof path around the house to keep the soil under the foundations at a steady moisture level.

Check your eligibility with the online simulator, or ask a free local adviser – both of which you can find here.

If you are eligible, you stand to receive between 70 and 90 percent of the cost of the diagnostic and of preventative works – the latter of which is capped at €14,000 excluding VAT.

Grants are paid at the end of each stage, so most owners have to pay the costs up front.