Guide · Rénovation
Damage-to-works insurance: the obligation almost nobody knows
An owner having works carried out must take out damage-to-works insurance before the site opens. What it covers, what its absence costs, and at resale.
It is the legal obligation most systematically ignored by private individuals who renovate, and the one whose absence costs the most, often years later. An owner having works carried out that fall under the ten-year guarantee must take out damage-to-works insurance before the site opens. Almost nobody does, and almost nobody knows.
This guide explains what it is for, when it applies, and why it matters particularly to an owner living abroad. It complements our reference page on works and renovation.
What it does, and why it exists
When a serious defect appears after works, the contractor is covered by their ten-year guarantee. But it must first be established that the defect really is their responsibility, and not that of the plasterer, the roofer, the architect or the material manufacturer. That demonstration takes place in court, with a judicial expert survey, and it takes between two and five years.
Damage-to-works insurance exists so you do not have to wait. It compensates you quickly, on simple observation of the defect, without identifying who is at fault. The insurer then turns against whoever is responsible and their colleagues. It is sometimes called pre-financing insurance, and that is exactly what it is: it buys time, not a new right.
When it is compulsory
The criterion is not the cost of the works but their nature: what is covered are works falling under the ten-year guarantee, meaning those compromising the soundness of the structure or making it unfit for purpose.
| Works covered | Works generally outside the scope |
|---|---|
| Structural work, reinforcement, opening a load-bearing wall | Replacing a boiler or a radiator |
| Roof framing, roofing, terrace watertightness | Laying a floor covering or painting |
| External insulation, facade renovation with insulation | Replacing separable equipment |
| Conservatory, extension, adding a storey | Small repairs and handyman work |
| Services embedded in the structure | Kitchen or bathroom without structural work |
For a standard flat renovation, without touching the structure, the obligation does not apply. It does apply as soon as you open a load-bearing wall, insulate externally or redo a roof, which is precisely the programme of a large-scale energy renovation. Our guide on a landlord’s options when rated F or G shows when you cross into that scope.
What its absence really costs
A private individual having works carried out for themselves incurs no criminal penalty: the obligation is criminally enforced against professionals, not against them. That explains why it is so widely ignored, and it is short-sighted reasoning.
The first cost is delay. Without damage-to-works insurance, water ingress appearing four years after roofing works is settled by court proceedings: expert survey, joining the companies and their insurers, judgment. Meanwhile the defect worsens and the repairs remain at your expense.
The second cost appears at resale. The notarial deed mentions works carried out within the past ten years and the existence, or not, of the corresponding insurance. An informed buyer draws two conclusions: they inherit an uncovered risk, and they can put a figure on it. Negotiation opens on that point, and it rarely closes in your favour.
For a non-resident owner, a third cost is added, invisible in the texts: distance. Following a judicial expert survey in Paris from Singapore or New York requires an agent, travel, and an availability nobody has.
How to take it out, and when
The rule has no exception: before the site opens. Once works have started, insurers decline the file, and the rare regularisation policies cost far more and require a survey of the works already carried out.
The file requested is always the same, and it is assembled alongside the quotes.
- The description of the works and the signed quotes.
- The ten-year insurance certificates of each company, in force and covering the activity performed.
- The plans, and the technical study where there is one.
- The name of the project manager or architect, if there is one.
- The planned date for opening the site.
The premium is calculated as a percentage of the cost of the works and is paid in one go. It follows the property and not the owner: if you sell, it benefits the buyer for the remaining period, which makes it one of the few site costs recovered in the sale price.
What we do
This is a point we check systematically before a site opens, because it cannot be caught up. We assemble the file with you, we obtain the companies’ ten-year insurance certificates and check their validity and scope of activity, which our guide on what to check before signing a quote details. Taking out the policy itself belongs to an insurer, towards whom we direct you.
To frame a project before opening the site, the complimentary personal study is the starting point.
Frequently asked questions
Which works require damage-to-works insurance?
Those covered by the ten-year guarantee, that is works affecting the soundness of the structure or elements that make it unfit for purpose: structural work, framing, watertightness, heavy insulation, embedded services, conservatory, adding a storey. Replacing a boiler or laying a floor covering are not in principle covered by the ten-year guarantee, so not by the obligation.
What is the risk of not taking it out?
A private individual building for themselves incurs no criminal penalty, unlike a professional. The risk is purely economic, and twofold: in the event of a defect you must prove the company's liability in court before being compensated, which takes years; and on resale within ten years, the buyer sees the absence of insurance in the deed and negotiates, when they do not walk away.
Can it be taken out after the works have started?
No, and that is why so many projects go without it: it must be taken out before the works begin, and insurers systematically decline a file submitted afterwards. So-called regularisation policies exist, but they are rare, expensive, and conditional on a prior survey of the works already carried out.