Ten-Year Structural Warranty and RGA Clay-Shrinkage Cracks

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The ten-year structural warranty (decennial warranty, French Civil Code art. 1792) covers damage that compromises the sturdiness of a building or renders it unfit for its purpose. But its application to cracks linked to clay shrink-swell (RGA) is not automatic.

Conditions for Invoking the Decennial Warranty

• The cracks must compromise the sturdiness of the structure (through-cracks, structural defects)
• Or render the structure unfit for its purpose (water infiltration, loss of watertightness, danger)
• A causal link with a construction defect must be established (e.g., foundations inadequate for the soil type)
• The claim must be filed within 10 years of the handover of the works

How Does the Expert Establish the Link?

The expert analyses the soil type (laboratory testing), examines the foundations (depth, type, compliance with building standards), characterises the cracks (orientation, width, progression), and studies climate data. If the foundations are appropriate for the soil and the cracks stem solely from the natural phenomenon, the decennial warranty may not apply.

Role of the Party-Appointed Expert

The party-appointed expert assists the lawyer in demonstrating that the builder failed to account for RGA risk when sizing the foundations. This is a key factor in the success of any legal action.

RGA Cracks: Decennial Warranty, Structural Damage Insurance, or Natural Disaster (CatNat) Procedure?

These three schemes are often confused, yet they follow different logics. The decennial warranty holds the builder liable for a design or execution defect. Structural damage insurance (dommages-ouvrage), taken out by the property owner, provides fast compensation without waiting for a court ruling on liability, with the insurer later pursuing the at-fault builder. The CatNat (natural disaster) procedure, on the other hand, requires no construction fault: it compensates for a natural phenomenon officially recognised by government decree, through home insurance.

Case Law: The Courts’ Position

Courts generally require rigorous technical proof of the link between the damage and a foundation design defect (insufficient depth relative to standard NF P 94-261, lack of a required soil survey, non-compliance with DTU 13.11 building code). Conversely, where the foundations comply with best practice and only the exceptional climatic phenomenon is at fault, the builder’s decennial liability is harder to establish – making the CatNat route the more relevant option.

Building a Solid Case

• Soil survey (G1/G2) carried out before construction, or its absence
• Foundation execution drawings and inspection report
• Crack-monitoring records documenting progression
• Local climate history (Météo-France data, successive CatNat decrees)

FAQ

Can the builder be exempted by invoking exceptional drought? They may attempt to invoke force majeure, but courts rarely accept this if building regulations were not followed during construction.

Do I need a lawyer as well as an expert? Yes, for any decennial warranty claim brought before a court: the technical expert and the lawyer work as a team, one establishing the facts, the other translating them into legal argument (expert opinion brief).

Cassini Expertise – Decennial warranty expertise for the Alpes-Maritimes (06), Var (83) and Bouches-du-Rhône (13). Request an assessment →

📅 Updated 16 August 2026 – By Cassini Expertise, independent building expert for the Alpes-Maritimes & Var. Free quote: 04 22 46 06 04.

Frequently Asked Questions

Does the decennial warranty cover cracks caused by clay shrink-swell (RGA)?

Yes, the decennial warranty can cover cracks caused by RGA if they compromise the sturdiness of the building or render it unfit for its purpose. The damage must have appeared within 10 years of the works’ handover and result from a design or execution defect.

What are the conditions for being compensated for RGA cracks under the decennial warranty?

You must prove that the cracks render the building unfit for its purpose or threaten its sturdiness, that they result from an unaddressed soil defect or poorly suited foundations, and that they appeared within the ten-year period. An expert assessment is needed to establish the link between the RGA and the damage.

How do I invoke the decennial warranty for RGA cracks?

First report the claim to your insurer within the required timeframe, then have the damage assessed by an expert. Next, a formal notice must be sent to the builder or their insurer. If no resolution is reached, you can bring the matter before the judicial court within 10 years of the handover.

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Survey carried out by Frédéric Faucouneau, independent building expert – Antibes, Alpes-Maritimes (06), Var (83), Bouches-du-Rhône (13). Find out more

📅 Last updated 06/11/2026 - Cassini Expertise, independent building expert – departments 06, 83 and 13.