Defects Revealed After the Ten-Year Guarantee: Contractual Liability and Wilful Misconduct of the Builder

An investor acquires an investment building renovated three years earlier by a property dealer (marchand de biens), lets the asset, and then discovers, in the eleventh year, widespread leaks in the flat roof. The seller has disappeared, the roofing contractor is in liquidation, no acceptance report appears in the sale file, and the dommages-ouvrage insurer (the insurer covering structural damage before any liability is established) argues that its cover has expired. The question is no longer whether the building suffers from a defect, but whether a solvent debtor and an available legal basis remain. This analysis addresses defects revealed after the ten-year period has expired or in the absence of acceptance of the works, the regime of ordinary contractual liability, the builder's wilful misconduct (faute dolosive), the five-year limitation period, and the practical interplay with the expert-appointment summary proceedings (référé-expertise) under Article 145 of the French Code of Civil Procedure.

Acceptance, not the date of the works, determines the applicable regime

The recurring error at the acquisition stage is to reason on the age of the works. Construction law does not reason that way: it reasons on acceptance.

A single triggering event for all statutory guarantees

Article 1792 of the French Civil Code establishes strict liability of the builder towards the client (maître de l'ouvrage) and successive purchasers, for damage that impairs the structural soundness of the work or renders it unfit for its purpose. Article 1792-4-1 fixes its duration: ten years from acceptance. Article 1792-3 provides for the guarantee of proper functioning of separable equipment items, for two years. Article 1792-6 provides for the completion guarantee (garantie de parfait achèvement), for one year.

All three periods run from acceptance, which Article 1792-6 defines as the act by which the client declares that it accepts the work, with or without reservations. Without acceptance, none of these guarantees has a starting point, so none applies. An investor seeking to invoke a ten-year guarantee without acceptance of the works relies on a basis that does not exist: the dispute shifts entirely to ordinary contractual liability, with the evidential and insurance consequences detailed below. The forms of this act and its effects on the allocation of risk are set out in our article on acceptance of works.

Article 1792-4-3 completes the scheme for defects that do not reach the gravity required for the ten-year guarantee, so-called intermediate defects and damage to existing structures:

Apart from the actions governed by Articles 1792-3, 1792-4-1 and 1792-4-2, liability actions against the builders referred to in Articles 1792 and 1792-1 and their subcontractors are time-barred ten years from acceptance of the works.

Here again, acceptance sets the countdown.

Tacit acceptance and judicial acceptance: two ways to remedy the absence of a report

The absence of a signed report is not fatal. Case law has long admitted tacit acceptance, inferred from the client's unequivocal intention to accept the work. Trial courts traditionally rely on a body of indicators: actual taking of possession, full or almost full payment of the price of the works, absence of any complaint at the end of the works, subscription to utilities, letting. The Third Civil Chamber of the Cour de cassation has relaxed this analysis by laying down a presumption of tacit acceptance where taking of possession is combined with payment of the price, a presumption that the builder or the insurer may rebut.

Judicial acceptance is the second route: the trial judge may order acceptance and set it at the date on which the work was in a condition to be accepted, including retroactively. The benefit for the investor is twofold. On the positive side, it opens access to the statutory guarantees and to compulsory insurance. On the negative side, it may turn against the claimant: if tacit acceptance is set at an early date, the ten-year period has expired and the action is time-barred. The date of acceptance is therefore not a neutral feature of the file but a matter of procedural strategy, to be decided before the writ is issued and not during the expert's investigation.

Defects after the ten-year guarantee: what remains beyond ten years

Once the period under Article 1792-4-1 has run, the statutory guarantees are extinguished. The bar is complete, even where the defect was undetectable. This is the very logic of the probationary period: it penalises the passing of time, not knowledge of the damage.

Return to ordinary contractual liability

What remains is ordinary law under Articles 1231-1 et seq. of the French Civil Code, for the client bound to the builder by a works contract, and Article 1240 for third parties. This basis is theoretically open but practically locked: the Cour de cassation holds that the statutory guarantees of Articles 1792 et seq. exclude any other basis for defects that fall within their scope. A client cannot circumvent the ten-year bar by recharacterising its action as ordinary contractual liability.

The lock has one exception, and in practice only one: wilful misconduct (faute dolosive). The entire value of a case concerning a defect after the ten-year guarantee rests on it.

Wilful misconduct, the only lever genuinely available

Case law holds that a builder who, deliberately, even without intent to harm, breaches its contractual obligations by concealment or fraud commits wilful misconduct, which prevents it from relying on the statutory probationary periods. Its basis becomes ordinary contractual liability, subject to the five-year limitation period under Article 2224 of the French Civil Code: five years from the day on which the right holder knew or should have known the facts enabling it to bring its action. All of this is contained within the twenty-year long-stop period running from the day the right arose, laid down by Article 2232.

The difference between the regimes is considerable. The ten-year period runs from acceptance, an objective and distant event. The five-year period for wilful misconduct runs from the revelation of the damage in its extent and attributability, an event that may be very recent. A purchaser who discovers in 2026 a defect affecting works accepted in 2012 is time-barred under the ten-year guarantee, but admissible on the basis of wilful misconduct if the discovery post-dates 2021 and the misconduct is established.

It should nevertheless be noted that there has been a shift: in recent years the Third Civil Chamber has tightened the definition of wilful misconduct, requiring proof that the builder was aware of the damaging nature of its breach, and not merely a deliberate breach of a rule of good practice. The objective seriousness of the breach is no longer sufficient; a subjective element must be established. This development raises the standard of proof and makes the court-appointed expert's report decisive.

The insurance coverage gap, the main risk for the renovated asset

Article L. 242-1 of the French Insurance Code requires any person who has construction works carried out, as owner, seller or agent, to take out dommages-ouvrage insurance. This policy pre-finances the repair of defects of a ten-year nature, without any inquiry into liability, and passes to successive purchasers of the building. Its duration follows that of the ten-year guarantee: ten years from acceptance, after the first year of the completion guarantee. The insurer's response periods and the sanction for its silence are examined in our article on claiming under the dommages-ouvrage guarantee.

Two situations deprive the investor of this cover.

The first is the absence of acceptance. Without acceptance, the dommages-ouvrage insurance has no starting point and the insurer refuses cover. The second is the outright failure to take out the policy, which is frequent where the works were commissioned by a private seller or by an unscrupulous property dealer. Article L. 243-3 of the French Insurance Code punishes this failure with six months' imprisonment and a fine of €75,000, except where an individual builds for himself or herself. The criminal penalty does not compensate the purchaser; it does, however, support the argument on the seller's bad faith.

A counter-intuitive consequence must be added, which lies at the heart of the strategic choice in these cases. Article L. 113-1, paragraph 2, of the French Insurance Code excludes from cover the intentional or wilful misconduct of the insured. The ten-year liability insurer, where it is still within the time limits, systematically relies on this exclusion whenever the claim is based on the builder's wilful misconduct. In other words, the basis that makes it possible to overcome the time bar is also the one that neutralises the insurer. The judgment obtained is then worth only what the works contractor's balance sheet is worth.

The practical consequence is simple: before commencing proceedings based on wilful misconduct, the builder's solvency must be checked, including filed accounts, any pending collective proceedings, deregistration, the manager's assets and any personal guarantees. An unenforceable judgment against a deregistered company is a worthless asset.

Establishing wilful misconduct: what the expert's investigation must establish

Wilful misconduct is not pleaded in general terms. It is demonstrated by material evidence that only a properly framed court-appointed expert investigation can gather. The situations most frequently accepted by the courts fall into a few categories.

• Concealment of a defect known at the time of execution: superficial repair of a structural crack covered with a render, laying of a covering on a substrate whose dampness had been noted, concealment of a defective load transfer.
• Deliberate and systematic departure from good practice and from the unified technical documents (documents techniques unifiés), where it reflects a cost-saving choice: absence of an underlay membrane, insufficient slope on a flat roof, non-compliant waterproofing upstands, absence of ventilation beneath the insulation.
• Undeclared substitution of materials as against the contract and the specifications of the project manager (maître d'œuvre).
• Production of an inaccurate or expired ten-year insurance certificate, or one that does not cover the activity actually carried out.
• Recourse to undeclared subcontracting to a company without qualifications or insurance.
• Knowing inaction in the face of a written warning from the project manager, the inspection body or the coordinator.

A case of roof defect where the ten-year guarantee has expired illustrates the mechanism well. Redoing a roof covering while retaining a roof frame whose dampness and fungal attack had been noted by the contractor, without treatment or notice to the client, is the type of breach capable of being characterised as wilful: the builder knew of the risk and covered it up. Conversely, an isolated execution defect, however costly, does not in itself constitute wilful misconduct.

The demonstration therefore rests less on the visible defect than on the traceability of the works: minutes of meetings, emails recording decisions, variation quotes, joint-expenses accounts, inspection body reports, reservations made at acceptance and never lifted. These documents are held by the builder, the project manager and the seller. Their production must be requested as early as the summary proceedings order, failing which they may never be obtained.

The other debtors: seller, seller deemed a builder, other parties involved

An action against the builder does not exhaust the dispute. For the purchaser of a renovated building, the seller is often the most accessible and most solvent target.

The seller deemed a builder (Article 1792-1)

Article 1792-1, 2°, of the French Civil Code deems a builder any person who sells, after completion, a work that he or she has built or had built. This characterisation is decisive for acquisitions from property dealers and heavy-renovation operators. It subjects the seller, by operation of law, to the regime of Articles 1792 et seq., without the seller being able to shelter behind a guarantee exclusion clause. The works must nevertheless amount to a work or to inseparable elements within the meaning of the text: heavy renovation affecting the structure, the roof, the floors, the waterproofing or the weatherproof envelope (clos et couvert) falls within scope; a simple refresh does not.

The characterisation of the seller as a deemed builder reopens, against the seller itself, the reasoning on wilful misconduct where the ten-year period has expired.

Latent defects and non-warranty clause

The action for latent defects under Article 1641 remains open against the seller. Article 1648, paragraph 1, confines the action to a period of two years from discovery of the defect. The judgments of the mixed chamber (chambre mixte) of the Cour de cassation of 21 July 2023 clarified the nature of this period by holding that it is a limitation period, capable of suspension and interruption, itself contained within the twenty-year long-stop period running from the day of the sale.

The clause excluding warranty for latent defects, inserted in almost all sale deeds, does not produce the effect the seller expects in two situations. Article 1643 deprives it of effect where the seller knew of the defect. In addition, case law deprives of effect the clause relied on by a professional seller, to whom knowledge of the defect is imputed. A renovating property dealer, a developer, or a property company that managed the works are in this position.

Finally, the purchaser benefits from the transfer, as an accessory of the building, of the liability actions that its seller held against the builders. The non-warranty clause stipulated for the seller's benefit does not prevent the exercise of these actions against third-party builders. The purchase of an asset therefore carries with it the purchase of a portfolio of claims, provided that the documents enabling them to be exercised have been obtained. For the purchaser of a recent dwelling, the extent of what is thus transferred is analysed in our article on the ten-year guarantee and the purchase of a recent dwelling.

The decision timetable: expert-appointment proceedings and management of time limits

In these cases, the costliest strategic mistake is delay. The discovery of a defect simultaneously starts a limitation period and a physical deterioration of the asset.

Article 145 of the French Code of Civil Procedure makes it possible to obtain, before any trial, an investigative measure where there is a legitimate reason to preserve or establish the evidence of facts on which the outcome of a dispute may depend. It is the central tool. The court-appointed expert's investigation establishes the technical origin of the defect, its date of appearance, its attribution among the parties involved, the cost of repair and, where the mission is properly drafted, the material elements of the wilful misconduct. On the procedural course, the conditions of the legitimate reason and the drafting of the mission, see our analysis of the expert-appointment summary proceedings (référé-expertise) based on Article 145 of the French Code of Civil Procedure.

Two mechanisms govern the timetable. The summons in summary proceedings interrupts the limitation period pursuant to Article 2241 of the French Civil Code. Article 2239 then suspends the period where the judge grants an application for an investigative measure made before any trial, the period starting to run again for a duration which may not be less than six months from the day on which the measure was carried out, that is, from the filing of the report.

Three points of vigilance follow. The first concerns the scope of the defendants: the interruptive effect applies only to the parties joined in the expert proceedings. A builder, a subcontractor or an insurer brought in late may plead that limitation has accrued in its favour. The list of parties must be settled before the summons, on the basis of the contract documents and not merely the seller's statements. The second concerns the post-report period: the residual six-month period is short and leaves no room for delay between the filing of the report and the summons on the merits. The third concerns the starting point of the five-year period: basing the action on the revelation of the damage requires the date of that revelation to be precisely documented, failing which the defendant will argue that the purchaser should have known the facts from the time of the acquisition.

Quantifying the claim: damages for defective workmanship on the investor's side

The principle of full compensation governs the assessment: the victim must be put back in the position it would have been in had the damage not occurred, with neither loss nor gain. Damages for defective workmanship are therefore not limited to the repair quote.

An institutional investor or a professional landlord usefully documents several distinct heads of loss: the cost of the remedial works, assessed at the date closest to the decision and not at the date of the defect; the project management and technical inspection costs relating to the repair; the loss of rent during the period of unavailability, supported by the leases and rent receipts; the cost of rehousing or temporary eviction of tenants; charges and taxes borne without consideration; the residual loss of market value where the repair does not restore the initial value of the asset; the costs of the amicable expert report and of the record of findings.

Two points of friction arise systematically. First, wear and betterment: the defendant argues that the repair improves the work and seeks a reduction. The answer is to show that the repair solution recommended by the expert is the necessary technical solution, not a voluntary enrichment. Second, the treatment of VAT, depending on whether or not the investor recovers it, which requires reasoning in amounts exclusive or inclusive of tax according to the tax regime of the asset.

It should be recalled that in French law the victim is not required to mitigate its loss in the interest of the person liable. However, prolonged inaction in the face of known leaks exposes the owner to an apportionment of liability for aggravation of the loss, particularly where the owner is a real estate professional.

Securing the position upstream: construction due diligence on acquisition

All of this litigation can be prevented at the acquisition audit stage. The market makes this vigilance all the more necessary: the energy renovation timetables imposed by Law No. 2021-1104 of 22 August 2021, known as the Climate and Resilience Law, with the ban on letting dwellings rated G since 1 January 2025 and dwellings rated F from 1 January 2028, have generated a massive volume of works carried out in haste, external thermal insulation, roof repairs, ventilation, by companies that are sometimes short-lived. Defects linked to thermal bridges, interstitial condensation and insufficient ventilation emerge several years after execution.

The list of documents to require before signing is short and non-negotiable:

• the acceptance report for each work package, dated and signed, with the list of reservations and the documents recording their lifting
• the dommages-ouvrage insurance and ten-year civil liability insurance certificates, in the relevant company's name, stating the activities covered and the period of validity in relation to the date of commencement of the works
• the works contracts, quotes, amendments and the file of executed works
• the reports of the inspection body and, where applicable, of the health and safety coordinator (SPS)
• the planning authorisations, the declaration certifying completion and conformity of the works, and the absence of any challenge
• the identity and current financial position of the companies involved, and whether subcontracting was declared

The absence of an acceptance report or of a dommages-ouvrage certificate does not rule out the acquisition. It requires that it be treated for what it is: an uninsured risk exposure, which translates into a price reduction, a specific asset and liability warranty, a retention held in escrow or a condition precedent of regularisation.

Key takeaways

The ten-year period is not a risk horizon, it is a guarantee horizon. Beyond ten years, or in the absence of acceptance, the investor no longer has a quasi-automatic right to compensation but a dispute about evidence, in which everything turns on establishing deliberate conduct by the builder and on the debtor's residual solvency. Wilful misconduct is a real lever, but a costly one: it requires a high standard of proof and neutralises the insurer. It never replaces a properly constituted chain of guarantees at acquisition.

Two reflexes are required in practice. At acquisition, never accept delivery of an incomplete works file in exchange for a mere statement by the seller: the absence of an acceptance report and of a dommages-ouvrage certificate must be reflected in the price or secured by a contractual guarantee. On discovery of a defect, have the revelation dated immediately by a record of findings and apply to the judge in summary proceedings under Article 145 of the French Code of Civil Procedure, joining from the outset all the parties involved and the insurers. Each month of delay moves the limitation cursor and weakens the evidence of the misconduct.

Frequently asked questions

Can a builder still be sued for defective workmanship after the ten-year guarantee has expired? Yes, but on a distinct and demanding basis. The statutory guarantees of Articles 1792 et seq. of the French Civil Code are extinguished on expiry of the ten-year period from acceptance set by Article 1792-4-1. What remains is ordinary contractual liability in the case of wilful misconduct by the builder, that is, a deliberate breach of its obligations, by concealment or fraud, with awareness of the damaging nature of the breach. The action is then time-barred after five years from the revelation of the damage (Article 2224), within the twenty-year long-stop period of Article 2232.

Does the ten-year guarantee apply without acceptance of the works? No. Acceptance is the triggering event for all the statutory guarantees and for dommages-ouvrage insurance. Without acceptance, none can be invoked. Two correctives exist: tacit acceptance, which the courts infer in particular from taking of possession accompanied by payment of the price, and judicial acceptance, which the judge may order by setting it at the date on which the work was in a condition to be accepted. This date must be chosen with care, since an early retroactive acceptance may time-bar the ten-year action.

What is the starting point of the five-year period in the case of wilful misconduct? The day on which the client or the purchaser knew or should have known the facts enabling it to bring its action, that is, the revelation of the damage in its extent and attributability. In practice, the court-appointed expert's report is frequently taken as the marker of that revelation, but the defendant will try to move the starting point back to the date of the first visible signs. The dating of the first manifestations of the defect, by a commissaire de justice's record of findings (bailiff) or by letter, determines the admissibility of the action.

Does the builder's ten-year insurance cover a judgment based on wilful misconduct? In principle, no. Article L. 113-1, paragraph 2, of the French Insurance Code excludes from cover the intentional or wilful misconduct of the insured, an exclusion that insurers systematically rely on on this basis. The judgment then remains the sole responsibility of the works contractor. Before commencing proceedings on this footing, it is necessary to check the builder's financial position, the existence of any collective proceedings and, where appropriate, the possibility of a complementary action against the seller or the other parties involved.

Can a property dealer who renovated the building be treated as a builder? Yes. Article 1792-1, 2°, of the French Civil Code deems a builder any person who sells, after completion, a work that he or she has built or had built. This characterisation applies to heavy renovation operations affecting the structure, the weatherproof envelope, the waterproofing or the floors. It subjects the seller to the strict liability of Article 1792 and deprives of effect the non-warranty clauses inserted in the deed of sale.

What losses can a landlord have compensated for a roof defect? Beyond the cost of remedial works and the associated project management fees, a landlord documents the loss of rent during unavailability, the tenants' rehousing costs, charges and taxes borne without consideration, the residual loss of market value of the asset and the costs of the amicable expert report. The principle of full compensation applies, with neither loss nor gain for the victim. Prolonged inaction in the face of known leaks does, however, expose the owner to an apportionment of liability for aggravation of the loss.

Should the judge in summary proceedings be seised before or after the works have been costed? Before. The expert-appointment summary proceedings under Article 145 of the French Code of Civil Procedure require a legitimate reason, not a prior costing. The summons interrupts limitation only as against the parties joined (Article 2241), and the investigative measure ordered then suspends the period until the filing of the report, after which a residual period runs that may not be less than six months (Article 2239). Waiting for a complete amicable costing wastes limitation time and leaves the builder in control of the works documents.