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Construction Defects: How to Use the Ten-Year Structural Warranty

When you undertake construction or major renovation works, you benefit from essential legal protection: the ten-year structural warranty (garantie décennale). This mandatory insurance covers serious defects for ten years that may compromise the building’s structural integrity or render it unfit for habitation.

In demanding property markets — particularly in Paris and the high-end segment — understanding how to activate the ten-year warranty is crucial to protecting your real estate assets.

What Is the Ten-Year Structural Warranty?

The ten-year warranty covers all damage affecting the structural integrity and weatherproofing of a building — in other words, elements ensuring resistance to water and air infiltration (roofing, load-bearing walls, framework, foundations, embedded pipes, etc.).

It applies to both new constructions and major renovation works and protects the property for 10 years from the formal acceptance of the works (réception des travaux).

Its purpose is to ensure the repair of defects or construction faults likely to:

  • compromise the structural stability of the building,

  • affect essential structural components (e.g., framework),

  • cause plumbing defects embedded in the structure,

  • lead to water infiltration damaging roofs or walls,

  • ultimately render the property uninhabitable.

No contractual clause may limit or exclude the scope of the ten-year warranty.

How to Activate the Ten-Year Warranty

To use the ten-year warranty, several steps must be followed carefully.

Notify the Contractor

As soon as you identify a defect, you must formally notify the company that carried out the works and request repairs.

This must be done by registered letter with acknowledgment of receipt.

Your letter should include:

  • a detailed description of the defect,

  • the date the damage was first observed,

  • photographs illustrating the issue,

  • any useful information identifying the origin of the problem.

Activate the Construction Damage Insurance (Dommages-Ouvrage)

If the contractor fails to carry out the necessary repairs, you may declare the claim to your construction damage insurance (assurance dommages-ouvrage), also by registered letter with acknowledgment of receipt.

Once activated:

  • the insurer has 90 days to make a compensation offer,

  • upon acceptance, payment must be made within 15 days.

If the contractor has ceased operations or disappeared, you may directly contact the contractor’s ten-year insurer.

It is therefore essential to keep the contractor’s insurance policy number for the full 10-year period following acceptance of the works.

What If the Ten-Year Warranty Has Expired?

If the ten-year warranty has expired, other legal remedies may still be available.

You may attempt to invoke the hidden defects warranty (garantie des vices cachés), provided three cumulative conditions are met:

  • the defect was unknown at the time of acceptance of the works,

  • the defect can be objectively established (photos, reports, expert assessments),

  • the defect is directly linked to the original construction.

If the damage results from an event occurring after acceptance of the works, the ten-year warranty cannot be invoked.

In case of uncertainty, consulting a building expert is strongly recommended to assess the situation.

Another potential remedy involves claiming intentional fault (faute dolosive) — a legal concept referring to the concealment of contractual obligations by the contractor, even without intent to cause harm.

Key Takeaways

The ten-year structural warranty is a powerful protection tool for property owners, particularly in residential and high-end real estate.

By understanding your rights and following the proper procedures, you can act quickly and effectively in the event of construction defects — and safeguard the long-term value of your property.