Disclaimer: This guide is for informational purposes only and does not constitute legal advice. French construction law is complex and fact-specific. For any dispute or claim, consult a qualified avocat specialising in droit de la construction. The author and dt-plans.com disclaim all liability for decisions made based on this content. Legal frameworks change — verify current provisions on Légifrance before acting.
Last updated: June 2026. This guide is reviewed annually.
If you're building, renovating, or buying a recently completed property in France, these two insurance schemes affect you directly. Most people confuse them, conflate them, or ignore them entirely until a ceiling cracks five years after handover. This guide covers both: who subscribes what, what's actually covered, and the part nobody puts in the brochure, which is what happens when you try to claim.
The 30-second version:
Both schemes were created by the loi Spinetta of 4 January 1978, which overhauled construction liability in France. The legal foundation sits in two places:
The key phrase in article 1792 is this: the constructor is liable de plein droit, meaning by presumption, without the client needing to prove fault, for any damage that compromises the structural integrity of the building or renders it unfit for its intended purpose, for ten years from reception.
That presumption is what makes the whole system work, and what makes it uncomfortable for insurers.
This is where most people get confused. They're not the same insurance. They don't cover the same person. They don't work the same way.
The garantie décennale is taken out by the professional: the contractor, architect, structural engineer, project manager, anyone whose work could engage their ten-year liability. It must generally be in place before the chantier opens, under current law. Not after. Not on the day. Before.
The assurance dommages-ouvrage (DO) is taken out by the maître d'ouvrage, the client, the person commissioning the works. Also before the chantier opens. It covers the same scope as the décennale, but it pays without waiting for a court to establish who's responsible.
One useful way to think about it:
Neither replaces the other. They're designed to work together.
Practical note: Even in cases where the DO is not legally mandatory, such as a private individual building for personal use, some mortgage lenders require it as a condition of financing. Check with your bank before deciding to skip it.
Before the décennale kicks in, there are two shorter guarantees worth knowing.
Garantie de parfait achèvement, 1 year. The contractor must fix any defect noted at reception or reported within the first year. Everything from a sticky door to a cracked render joint.
Garantie de bon fonctionnement (biennale), 2 years. Covers dissociable equipment, meaning things that can be removed without damaging the structure: radiators, electric shutters, water heaters. Two years from reception.
Garantie décennale, 10 years. The serious one. Structural defects and anything that renders the building unfit for its purpose. From the date of reception, regardless of who currently owns the building.
The legal test has two limbs, either of which triggers coverage:
In practice this includes: major fissures in load-bearing elements, roof leaks causing insalubrity, subsidence, waterproofing failures on buried walls, and severe thermal bridging making the building impossible to heat adequately. VMC failures can also be covered, but only when they lead to chronic condensation, mould, or insalubrity serious enough to constitute impropre à destination. Insurers contest this category regularly, and courts often require an expertise judiciaire to confirm the damage reaches that threshold. Document everything from the start.
What it does not cover: purely aesthetic damage, minor imperfections, dissociable equipment (that's the biennale), and anything caused by abnormal use or modifications made by the owner after reception.
This is the mechanism that makes the DO genuinely useful, and the clearest argument against skipping it.
Say a roof leak appears three years after reception. Water ingress, ceiling damage, mould developing.
With a DO: the client declares the sinistre to their DO insurer. The insurer has 60 days to take a position, 90 days to make an indemnity offer, and 15 days to pay after acceptance. Repairs are funded quickly, without waiting for anyone to establish fault. The DO insurer then recovers from the contractor's décennale insurer via subrogation, stepping into the client's legal shoes and pursuing that claim themselves.
Without a DO: the client goes directly to the contractor's décennale insurer. There are no legal deadlines on that insurer's response. They can take months. They can stall. The client has no fast-track mechanism and no subrogation working in their favour.
The legal deadlines on the DO are set by article L.242-1 of the Code des assurances:
Miss those deadlines and legal interest runs from the date of formal notice.
The décennale has no legal response deadline. None. Unlike the DO's strict 60/90/15 day framework, a décennale insurer can take months to respond to a claim and faces no penalty for doing so. An owner without DO cover can find themselves waiting indefinitely with no legal lever to force a response.
Beyond the timing issue, insurers have several lines of defence they tend to reach for.
The scope of activity argument. If the damage falls outside the activity declared by the contractor when subscribing their policy, the insurer declines. A mason who did some roofing work? If roofing wasn't in their declared activity, that work isn't covered.
The aesthetic damage argument. Any defect that can be characterised as purely cosmetic rather than structural gets pushed out of scope. This is where impropre à destination matters. If you can demonstrate the building is no longer fit for normal use, not just visually imperfect, coverage becomes much harder to refuse.
The modification argument. Works carried out on the building after reception, particularly anything touching structural elements, can void coverage on those zones. An owner who had a load-bearing wall opened up without a structural engineer after handover gives the insurer a solid exit.
The prescription trap. The defect has to reach the required severity threshold within the ten-year window. It's not enough that a bad foundation was laid. The damage has to have manifested to the required degree before the clock runs out. Microfissures can be refused unless an expert confirms they're evolving toward structural risk.
The declaration delay argument. Waiting too long to declare a sinistre after discovery can be used to justify refusal. Early declaration by LRAR, documented with photos and if possible a huissier's report, is the sensible move.
Not having a décennale in place when you open a chantier is a criminal offence.
Under current law, article L.243-3 of the Code des assurances provides for a 75,000€ fine and six months imprisonment, or either one, for professionals operating without the required cover.
For the DO: a private individual building for their own use or for direct family faces no criminal sanction for skipping it under current law. But they take on the full burden of any claim directly, with no fast-track indemnification and no subrogation mechanism behind them.
Options exist, but none of them are quick.
Send a formal letter by LRAR citing the specific articles the insurer is in breach of. If the DO insurer has missed the 60/90 day deadlines, legal interest runs from the date of formal notice.
The tribunal judiciaire is the correct jurisdiction for construction disputes. An expertise judiciaire, a court-appointed expert, is often required to establish the character of the désordre.
For direct action against an insurer, article 124-3 of the Code des assurances gives the injured party the right to proceed directly against the responsible party's insurer.
If a contractor cannot obtain décennale cover at all, the Bureau Central de Tarification (BCT) can be approached to set mandatory tariff conditions. Insurers cannot legally leave a qualifying contractor uninsurable. Note that the BCT process can take several months and is not a rapid fix.
This guide explains the system. It doesn't replace professional advice. Consult an avocat specialising in droit de la construction if:
All legal texts cited are available on Légifrance, the official French legal database:
This guide is for information only. For specific legal disputes, consult an avocat specialising in droit de la construction.