Invoking the ten-year guarantee against a craftsman: procedure and model letter

Tiling that cracks across an entire terrace two years after the works finished, a roof that lets water through in the first heavy storm, damp rising through the foundations of a new house: these serious defects often fall under the ten-year guarantee (garantie décennale), and not under a simple commercial dispute with the craftsman. One still has to know how to invoke it, in what order and with which letters. Many private individuals lose their rights because they write to the wrong party, let the ten-year period slip by or neglect to have the defects recorded by an expert. This guide sets out the procedure step by step, from the notification of the claim to legal proceedings, and provides a model formal notice letter that can be reused as it stands.

What the ten-year guarantee for a craftsman actually covers

The ten-year guarantee is based on Article 1792 of the French Civil Code, which derives from Law No. 78-12 of 4 January 1978, known as the Spinetta Law. The text establishes a presumption of liability borne by the builder:

Any builder of a structure is liable as of right to the owner or purchaser of the structure for damage, even resulting from a defect in the ground, which compromises the soundness of the structure or which, by affecting it in one of its constituent elements or one of its items of equipment, renders it unfit for its purpose.

Two essential ideas lie behind this wording. First, liability arises as of right: the client (maître d'ouvrage, the person who commissioned the works) does not have to prove fault on the part of the craftsman, and need only demonstrate the existence of the defect and its seriousness. Second, not all defects are covered: only those that compromise the soundness of the structure or render it unfit for its purpose are. The position of the purchaser of a recent dwelling, who is covered by the same text, is examined in our article on the ten-year guarantee and the purchase of a recent dwelling.

The defects that trigger the guarantee

The case law traditionally recognises two categories. Defects affecting soundness concern the structure itself: cracks running right through a load-bearing wall, subsidence of foundations, partial collapse of a roof frame. Defects rendering the structure unfit for its purpose cover situations in which the property can no longer be used normally: repeated water ingress making a room uninhabitable, a waterproofing defect in a flat roof terrace, a screed that comes away and prevents a floor covering from being laid.

Take a concrete example. An owner has a masonry conservatory built by a craftsman. Three years later, cracks appear at the junction with the house and water gets in whenever it rains. The room becomes unusable for part of the year. This defect renders the structure unfit for its purpose: the ten-year guarantee is intended to apply, regardless of any proven fault on the part of the craftsman.

The guarantees not to be confused

Understanding how to make the ten-year guarantee work first requires not confusing it with two neighbouring, shorter guarantees.

• The completion guarantee (garantie de parfait achèvement, Article 1792-6 of the French Civil Code) lasts one year from acceptance and covers all defects notified, including minor finishing defects.
• The guarantee of proper functioning, known as the two-year guarantee (garantie biennale, Article 1792-3 of the French Civil Code), lasts two years and concerns items of equipment that are separable from the structure: a roller shutter, a water heater, a motorised garage door.

The ten-year guarantee, for its part, runs for ten years (Article 1792-4-1 of the French Civil Code) and applies only to the serious defects defined in Article 1792. Tiling that comes away over a few square metres in a corridor will rather fall under the completion guarantee; the same defect, if widespread and making a room impossible to use, may move into the ten-year field. To determine which of these guarantees applies to a given defect, see our analysis entitled ten-year, two-year or completion guarantee.

Checking the three conditions before acting

Before taking any step, three cumulative conditions must be met. Checking them avoids writing pointless letters and wasting time on an action that is bound to fail.

First condition: there must have been acceptance of the works (réception). Acceptance is the act by which the client declares that it accepts the structure, with or without reservations (Article 1792-6 of the French Civil Code). It is what starts the ten-year period running. Where there is no signed acceptance report, the judges may sometimes find tacit acceptance, for example where the client has taken possession of the premises and paid the full price without objection.

Second condition: compliance with the ten-year period. The starting point is the date of acceptance, not the date the site finished or the date of the invoice. After that period, the action is extinguished and no ten-year remedy is possible any longer. This is the most frequent trap: a defect that worsens slowly may only be taken seriously after several years, leaving little room to act.

Third condition: the nature of the structure and the seriousness of the defect. The defect must affect a genuine construction work (a house, an extension, a roof, a paved floor slab) and be as serious as Article 1792 requires. A simple cosmetic defect in workmanship is not enough.

Step 1: gather the evidence and identify those responsible

The first practical step is to build a solid file. The presumption of liability makes it easier to prove fault, but the client must still establish the reality and extent of the defects.

All the contractual documents must be gathered: signed quotation, invoices, acceptance report, and the craftsman's ten-year insurance certificate handed over before the works. This certificate is valuable: it gives the name of the insurer, to whom the formal notice will have to be sent. The craftsman is in any event required to take out ten-year insurance under Article L. 241-1 of the French Insurance Code.

At the same time, the defects themselves must be documented: dated photographs, a report by a bailiff (huissier de justice) if the damage is significant, and emails or text messages exchanged with the craftsman acknowledging the problem. The better supported the file is at the outset, the more effective the subsequent expert investigation will be.

Identifying those responsible deserves attention. Where several trades were involved, liability may be shared among several craftsmen, or even go back to the project manager (maître d'œuvre) or the architect. In case of doubt, it is better to bring in all potential parties, leaving the expert investigation to clarify responsibilities afterwards.

Step 2: notifying the claim to the structural damage insurer

A private client who has a building constructed or major works carried out must in principle take out structural damage insurance (assurance dommages-ouvrage) under Article L. 242-1 of the French Insurance Code. This insurance has a major advantage: it provides advance financing of the repairs without waiting for a court to identify the party responsible. In practice, many private individuals have not taken it out, particularly for small projects, but where it exists, it is the place to start.

The claim is notified to the structural damage insurer by registered letter with acknowledgement of receipt. It must describe precisely the defects observed, the date they appeared and their location. The insurer then has time limits set by the French Insurance Code: it must decide whether the guarantee applies within sixty days and, if it accepts, make an offer of compensation within ninety days of receiving the notification. Going through the structural damage insurance spares the private individual from having to identify the party responsible first. These time limits and the penalty attached to the insurer's silence are set out in our article on making a structural damage insurance claim.

Where there is no structural damage insurance, the action is brought directly against the craftsman and its ten-year insurer, which is covered by the next step.

Step 3: the formal notice to the craftsman (model ten-year guarantee letter)

The formal notice (mise en demeure) is the pivot of the procedure. It aims to inform the craftsman officially of the defects, to invite it to act under its ten-year guarantee and to prepare, in the event of refusal, possible legal proceedings. This letter usefully interrupts the limitation period and provides dated proof of the claim.

It must be sent by registered letter with acknowledgement of receipt to the craftsman and, if possible, to its ten-year insurer, whose details appear on the insurance certificate. The letter is best kept factual, precise and dated. It is better to avoid aggressive wording or hazardous figures: the aim is to set out the facts and to fix a reasonable time for a reply.

Model ten-year guarantee letter

Here is a model ten-year guarantee letter that can be adapted as it stands. The items in square brackets are to be personalised according to the situation. This model can be copied, saved and downloaded for sending by registered post.

Subject: Formal notice under the ten-year guarantee, Article 1792 of the French Civil Code Registered letter with acknowledgement of receipt

[First name and surname] [Address]

For the attention of [Name of the craftsman or company name] [Craftsman's address] Copy to [Name of the ten-year insurer], policy No. [number shown on the certificate]

[Town], [date]

Dear Sir or Madam,

You carried out work at my home at [site address], namely: [description of the works, for example re-roofing], under the quotation signed on [date] and invoice No. [number] of [date]. The works were accepted on [date of acceptance].

Since [date the defects appeared], I have observed the following defects: [precise description, for example recurrent water ingress whenever it rains, and the appearance of stains and mould on the ceiling of the main room]. These defects [compromise the soundness of the structure / render the structure unfit for its purpose], as shown by the photographs and documents enclosed.

These defects fall under the ten-year guarantee provided for in Article 1792 of the French Civil Code, which makes you liable as of right for ten years from acceptance, in accordance with Article 1792-4-1 of the same Code.

Accordingly, I give you formal notice to carry out full repair of these defects, or to provide me with the details and the confirmation of cover from your insurer under your compulsory ten-year insurance (Article L. 241-1 of the French Insurance Code), within [for example fifteen days] of receipt of this letter.

Failing a reply or action within that period, I shall be obliged to apply to the competent court, in particular for the appointment of a court-appointed expert on the basis of Article 145 of the French Code of Civil Procedure, and to claim compensation for all of my losses.

Yours faithfully,

[Signature]

Enclosures: copy of the quotation, the invoice, the acceptance report, the ten-year insurance certificate, photographs of the defects.

This letter leaves the craftsman an amicable way out while setting out the legal framework clearly. In a large number of cases, receipt of a structured formal notice, mentioning the insurer and Article 145 of the French Code of Civil Procedure, is enough to unblock action.

Step 4: the expert investigation, the keystone of the file

If the formal notice has no effect, the expert investigation becomes decisive. Its purpose is to establish, with all parties heard, the reality of the defects, their cause, who is responsible for them and the cost of the remedial work. The judge will then rely on this report.

There are two routes. An out-of-court expert investigation, organised on the initiative of the parties or their insurers, has the advantage of speed but requires the craftsman's agreement. A court-ordered expert investigation, ordered by the judge hearing summary proceedings (juge des référés) on the basis of Article 145 of the French Code of Civil Procedure, is binding on all parties and offers better guarantees that all sides are heard. The client applies to the judicial court (tribunal judiciaire) in summary proceedings (référé) to obtain the appointment of an expert registered with the court of appeal.

During the expert investigation, the expert summons all the parties, examines the defects, hears their comments and drafts a report. This report sets out the technical origin of the damage, which makes it possible to determine whether or not the defect falls under the ten-year guarantee, and puts a figure on the cost of restoration. The quality of the file built up in step 1 has a direct bearing here: the stronger the initial evidence, the faster the expert investigation progresses.

One point to watch deserves emphasis. The defect must exist in its ten-year extent at the time of the expert investigation, but the case law accepts that progressive defects, which reach the required seriousness only over time, may be taken into account if they were incipient during the ten-year period. It is therefore preferable to act at the first signs rather than wait for the defect to worsen.

Step 5: legal proceedings on the merits

Where neither the formal notice nor the expert investigation has led to a settlement, there remain proceedings on the merits before the judicial court. They aim to have the craftsman, and where applicable its insurer, ordered to fund the repair of the defects and to compensate ancillary losses, for example loss of enjoyment where the dwelling could not be occupied normally.

The writ of summons must be served before the ten-year period expires. This is a crucial point: an action brought after ten years is inadmissible, even if the defects are beyond dispute. Where summary proceedings for an expert investigation have been commenced within the period, they interrupt the limitation period and secure the rest of the procedure.

Before the court, the presumption of liability works in the client's favour. The craftsman can escape liability only by showing an external cause: force majeure, fault of the client itself, or wrongful interference by the client in the design. This exoneration is narrowly construed by the judges, which makes the claimant's position solid provided the defect falls squarely within the scope of Article 1792.

Representation by a lawyer is compulsory before the judicial court for disputes above a certain threshold, and strongly recommended in any event given the technical nature of the subject. Having a lawyer from the formal notice stage also makes it possible to calibrate the time limits and not to jeopardise the claim through a procedural error.

Fitting the steps together: a timeline to follow

The five steps are not independent; they follow one another in a precise logic. Gathering the evidence determines the effectiveness of the expert investigation. The formal notice opens the amicable route while preparing the ground for court proceedings. The notification to the structural damage insurer, where there is one, can short-circuit a good part of the process by providing advance financing of the works. Finally, compliance with the ten-year period runs through the whole: each document must be dated and kept in order to prove, when the time comes, that the action was brought in time.

A frequent mistake is to multiply informal exchanges with the craftsman for months, without ever formalising a notice or starting an expert investigation, until one finds oneself a few weeks from the expiry of the ten-year period (forclusion). At that stage, only the prompt commencement of summary proceedings for an expert investigation can safeguard the rights.

Conclusion

Invoking the ten-year guarantee against a craftsman is not a question of bargaining power but of method and timetable. The law puts the client in a favourable position through the presumption of liability in Article 1792 of the French Civil Code, provided the three preliminary conditions are checked (acceptance, the ten-year period, seriousness of the defect), a convincing file is built, the right party is written to and the technical reality of the defects is established by an expert investigation. A structured formal notice, based on the model letter above, resolves a large number of situations without litigation; the expert investigation and proceedings on the merits take over where the craftsman remains silent.

The most useful advice fits in one sentence: never let the tenth year approach without having taken formal action. At the first serious defects, send the formal notice by registered post, notify your structural damage insurer if you have one, and have your file analysed by a property law lawyer before the ten-year period expires, because it is this deadline, and not the seriousness of the damage, that determines whether the claim succeeds.

Frequently asked questions

What is the difference between the ten-year, two-year and completion guarantees? The completion guarantee (Article 1792-6 of the French Civil Code) lasts one year after acceptance and covers all defects notified. The two-year guarantee, or guarantee of proper functioning (Article 1792-3 of the French Civil Code), lasts two years and applies to separable equipment such as a roller shutter or a water heater. The ten-year guarantee (Articles 1792 and 1792-4-1 of the French Civil Code) runs for ten years and concerns only serious defects that compromise the soundness of the structure or render it unfit for its purpose.

How can I make the ten-year guarantee work if the craftsman has ceased trading? The craftsman ceasing to trade does not make the guarantee disappear. It is the ten-year insurer that takes over, which makes the insurance certificate handed over before the works indispensable. If you have not kept it, structural damage insurance, where it exists, makes it possible to obtain advance financing of the repairs. Where no insurer can be identified, legal proceedings remain possible but their effectiveness depends on the solvency of the craftsman or of the person who took over the business.

Does the ten-year period start from the end of the works or from acceptance? It is the date of acceptance that starts the ten-year period running, and not the end of the works or the date of the invoice (Article 1792-4-1 of the French Civil Code). Acceptance is evidenced by a report signed by the client, with or without reservations. Where there is no report, tacit acceptance may be found where the owner has taken possession of the premises and paid the whole price without objection.

Is a simple registered letter enough to trigger the ten-year guarantee? The registered formal notice is indispensable to formalise the claim, but it is not always enough on its own. It informs the craftsman and its insurer, opens the amicable route and prepares legal proceedings. If it goes unanswered, an expert investigation must be started, generally in summary proceedings on the basis of Article 145 of the French Code of Civil Procedure, followed by proceedings on the merits before the judicial court, taking care to act before the ten-year period expires.

Is an expert investigation compulsory to obtain redress? In practice, an expert investigation is almost always necessary as soon as the craftsman disputes its liability or the nature of the defect. It establishes, with all parties heard, the cause of the damage, who is responsible and the cost of the remedial work, which are the elements on which the judge relies. A court-ordered expert investigation, ordered by the judge hearing summary proceedings, offers the best guarantees that all sides are heard and is binding on all parties.

What exactly does compensation under the ten-year guarantee cover? Compensation covers the cost of the work needed to restore the structure and make the defects disappear. It may also include ancillary losses, for example loss of enjoyment where the dwelling could not be occupied normally during the period of the defects. Redress extends to the whole of the damage falling within the ten-year field, which the expert investigation makes it possible to quantify precisely.

Can a private individual act alone, or is a lawyer compulsory? Before the judicial court, representation by a lawyer is compulsory above a certain threshold of claim and strongly advisable in any event given the technical nature of the subject. A private individual can send the formal notice alone and notify the claim to their insurer, but having a lawyer from that stage secures the time limits and avoids procedural errors liable to jeopardise the claim before the ten years expire.