Building Work Without Ten-Year Insurance: What Does the Client Risk?

A defect shows up on your home: cracks, water infiltration, a sinking slab. You contact the company to warn them and call on their ten-year (decennial) guarantee. Silence — or worse: « we weren’t insured for that type of work. » This is a situation we encounter regularly during expert assessments across the Alpes-Maritimes, the Var and the Bouches-du-Rhône, and it leaves the client in a very uncomfortable financial position.

The pain point: a serious defect, but no insurance behind it

The decennial guarantee (art. 1792 et seq. of the French Civil Code) covers, for ten years from handover, damage that compromises the structural soundness of the building or makes it unfit for its intended use. It is backed by compulsory insurance that every building company must take out before the site opens, under article L241-1 of the French Insurance Code. The problem arises in three scenarios we see on the ground: the company simply had no decennial insurance at all; it had insurance but for a different trade than the one carried out (for example, covered for painting but not for masonry); or its certificate had expired or been suspended for unpaid premiums at the time of the works. In all three cases, the client ends up having to fund the repair of the defect alone, despite believing they were protected.

What many homeowners don’t realise is that the absence of decennial insurance doesn’t make the legal guarantee disappear: it is still owed by the company itself, but without a solvent insurer behind it, recovering damages becomes largely theoretical if the company is small, in financial difficulty, or tempted to simply disappear.

Why it happened

Several mechanisms explain this situation, and they often overlap. First, the 1978 Spinetta law made decennial insurance compulsory, but no systematic check is carried out before a quote is signed. The client trusts a certificate that is shown to them, sometimes falsified or out of date, without verifying its actual validity with the insurer. Second, some companies knowingly operate without cover in order to offer lower prices, shifting the risk onto the client without telling them. Others do have insurance, but limited to certain trades: a structural-work company that is insured may subcontract waterproofing to a company that isn’t insured for that specific activity, and the client only discovers the gap once the defect appears. Finally, it happens that a company loses its cover during the year for non-payment of premiums, without informing its clients while the site is still under way.

Article L241-7 of the Insurance Code requires that the decennial insurance certificate state the activities covered and be handed over before the site opens. Failure to comply exposes the contractor to criminal penalties: article L243-3 of the same code provides for up to six months’ imprisonment and a €75,000 fine for a contractor who has not taken out the compulsory insurance. These penalties exist, but they don’t repair the defect found in your home.

What can be done

The first step is to genuinely verify the company’s insurance situation, rather than relying solely on the certificate supplied with the quote. You can ask the insurance company named on the certificate to confirm cover directly, or check the company’s professional register. If the absence or inadequacy of cover is confirmed, several avenues of recourse exist in parallel. First, a formal notice sent to the company by registered letter with acknowledgement of receipt, based on the decennial guarantee, remains necessary even if the insurer is absent: it stops the clock on time limits and forms an essential piece of your file. Next, if the company remains solvent (personal assets, an active company), legal action before the competent civil court — the Grasse court for the Alpes-Maritimes — can secure a judgment, even though enforcing it remains uncertain without insurance behind it.

You should also check whether your own « dommages-ouvrage » insurance, if you took one out, can step in: it pre-finances the repairs and then pursues the parties responsible itself, sparing you the wait for a lengthy legal process. Finally, in some cases, the liability of the project manager or architect who signed off on the site without checking the companies’ insurance certificates can also be pursued.

How the expert helps

In this type of case, the independent expert’s role is to precisely document the origin and technical severity of the defect, separately from the insurance question, which is a legal matter. We produce a factual report covering: the exact nature of the defect, the causal link with the work carried out, any non-compliance with accepted building standards and the applicable French technical standards (DTU) — for example DTU 20.1 for masonry or DTU 43.1 for waterproofing — and the costed estimate for repairs. This report, produced using professional Trotec measuring equipment for moisture, infiltration or structural deformation, serves as solid technical evidence, whether to negotiate with an insurer if cover ultimately exists, to support legal proceedings, or to make your case directly to the company.

Cassini Expertise is not tied to any building company: our report remains entirely independent, which gives it evidential weight before the courts and with insurers. We work across the Alpes-Maritimes, the Var and the Bouches-du-Rhône, drawing on fifteen years of experience in public works and project management that allow us to understand both the technical execution and the contractual responsibilities at stake.

Frequently asked questions

The company showed me a decennial insurance certificate — is that enough?
No. A certificate can be old, limited to certain activities, or the company may have stopped paying its premiums since it was issued. We recommend checking its validity directly with the insurer named on it, especially for a significant project.

Can I still take action against the company even without decennial insurance?
Yes, the decennial guarantee remains owed by the company itself as a legal obligation, regardless of its insurance status. The issue is actual enforcement: without a solvent insurer, recovery depends on the company’s real assets.

What if the company doesn’t respond to my formal notice?
You should then consider legal action before the competent civil court, backed by a technical expert report establishing the origin and repair cost of the defect.

Can an independent expert help before I even start legal proceedings?
Yes, a preliminary expert report often makes it possible to negotiate an amicable settlement, or at the very least to strengthen your file before any legal action.

Related reading

• Uninsured company
• Contractor did poor-quality work
• Contact

📅 Mis à jour le 25/09/2026 — Cassini Expertise, expert bâtiment indépendant (06·83·13·40).