National Solidarity Against RGA Is Quietly Being Transformed

The cost trajectory: what has already changed in 30 years

Clay shrink-swell subsidence was long a manageable line item in the accounts of the natural disaster scheme. In the 1990s and 2000s, its annual cost hovered around €400 million — significant, but stable, and absorbable through national risk-pooling.

Then something broke. Starting in 2016, prolonged summer droughts multiplied: 2017, 2018, 2019, then 2022, the year of record after record. That year alone generated €3.5 billion in RGA claims — eight times the average annual cost of the 1990s.

The Cat-Nat scheme held. But at what cost: in 2022, the Caisse Centrale de Réassurance (CCR) covered 62% of total Cat-Nat claims, versus an average of 52% since 1982. The stop-loss mechanism kicked in, shifting the risk onto the public reinsurer — and indirectly onto the state's unlimited guarantee.

Concretely, the trajectory is striking: around €400 million/year between 1989 and 2015, then around €1 billion/year between 2016 and 2020, a peak of €3.5 billion in 2022, and a CCR projection of between +83% and +103% by 2050.

According to CCR projections published in 2023, the average annual cost of geotechnical drought will rise by 83% by 2050 from climate change alone, and by 103% once the growth of the insured housing stock is factored in — up to €747 million more per year, in the best-case climate scenario.

The map has expanded: 55% of the territory now affected

The figure went relatively unnoticed when it was published in January 2026. The Ministry for Ecological Transition updated the national map of exposure to clay shrink-swell subsidence. The result: zones classified as medium or high exposure now cover 55% of mainland France.

For homeowners, this concretely means that houses in municipalities previously considered low-exposure now fall into medium-exposure zones — with all the implications that carries for insurance, property value, and access to prevention schemes.

Three figures sum up the scale of the shift: 55% of mainland France is now classified as medium or high exposure, 61.5% of the single-family housing stock is affected, and the CCR anticipates a minimum 47% rise in costs by 2050.

12.1 million existing single-family homes now sit in medium or high exposure zones — 61.5% of the housing stock. This is no longer a niche geographic issue: it's the climate risk that touches the largest number of homeowners in France.

The quiet tightening of eligibility criteria

The transformation of the Cat-Nat scheme isn't announced — it's happening. The 2024 circular tightened eligibility criteria by requiring a return period of more than 10 years on the soil moisture index. The result: in the single ministerial order of March 13, 2026, out of 251 municipalities that filed a drought claim, 212 were rejected — a rejection rate of 84%.

That figure deserves context. Between 1995 and 2004, Cat-Nat drought recognition requests were granted almost automatically. The reversal is radical: from an almost automatic system, we have moved to one that rejects 4 out of 5 requests.

"Only 50% of municipalities manage to obtain natural disaster recognition, and only 50% of claims filed in those municipalities receive compensation," notes Christine Lavarde, senator for Hauts-de-Seine, in a 2023 Senate information report.

The 2023 reform stemming from the 3DS law had relaxed certain criteria to better account for repeated and cumulative droughts. Applying it to 2022 data would reportedly have allowed "almost 20% more" recognitions, according to specialists in the field. Real progress, but insufficient given the scale of the phenomenon.

What is coming: a transformation in five acts

The Court of Auditors published a report in April 2026 whose recommendations sketch out the scheme's likely trajectory over the next ten years. Read closely, these recommendations describe less a maintained status quo than a gradual transformation.

Five shifts appear particularly likely, on different timelines:

The contrast is stark between today's situation and what is expected within five to ten years: from compensation after a claim with no prior condition, toward compensation conditional on preventive measures taken; from national solidarity blind to risk level, toward modulation based on exposure and homeowner behavior; from a single surcharge for all policyholders, toward differentiated pricing based on actual risk level; from RGA risk invisible in real-estate transactions, toward risk built into property prices through mandatory maps planned for 2027; and from unconditional coverage of rebuilding costs, toward higher deductibles for non-preventive homeowners.

First, surcharge increases will continue. The Cat-Nat surcharge has risen from 5.5% to 9%, then to 20% of the home insurance premium. The Court of Auditors recommends regular reviews with the possibility of exceptional adjustments. The 2025 increase won't be the last.

Second, RGA risk will be built into real-estate transactions. Recommendation No. 5 of the Court's report calls for forward-looking risk maps to be integrated into transactions by 2027. An unprotected home in a clay zone will mechanically be worth less.

Third, Cat-Nat recognition criteria will keep tightening. The Court recommends strengthening the independence of the Cat-Nat commission — meaning the end of recognitions granted under political pressure.

Fourth, mandatory prevention will gradually take hold. The recommendation to generalize "Build Back Better" makes compensation conditional on preventive standards — a first step toward differentiating between preventive and non-preventive homeowners.

Fifth, the system's financing will shift toward more differentiated pricing. Blind national solidarity — identical for everyone regardless of exposure — is incompatible with the cost trajectory. Modulation based on actual risk level has been technically possible since the map was revised.

The window to act from a position of strength

This transformation is neither imminent nor abrupt. It is gradual, which means a window still exists to position yourself on the right side of the divide.

A homeowner who takes preventive action on their foundations today gains several distinct advantages. They protect their property from the progressive degradation each drought inflicts on unprotected clay soil. They build documented proof of preventive behavior — increasingly relevant in a scheme moving toward conditionality. And they preserve their property's value at a time when RGA maps are set to become mandatory data in real-estate transactions.

The cost of a preventive solution — a soil moisture regulation system, far more accessible than micropiles or underpinning — is a fraction of the structural cost. But it is also, increasingly, a fraction of the property-value gap that RGA risk will create between protected and unprotected homes.

National solidarity against RGA is not disappearing overnight. It is being gradually transformed — becoming more selective, more conditional, more costly. The only way through this transformation without suffering its consequences is to act before it is complete. Today, a sound home is worth the price of a home. In five years, a protected home will be worth more than an exposed one.

The quiet transformation of the Cat-Nat scheme does not threaten homeowners who acted ahead of time. It penalizes those who wait.