Certificate of Conformity: The Builder Must Deliver a Building Conforming to the Contract

You have just bought a brand new flat in Montpellier, in the rapidly expanding Porte d'Espagne district. The developer has handed over the keys, everything seems perfect. But a few weeks later, you notice that the windows are poorly installed, the sound insulation is defective, and the terrace is not the size specified in the plan. You contact the builder, who retorts: 'Everything is in order, I have the certificate of conformity issued by the town hall.' So, does this official document prevent you from obtaining redress? The answer is no, and it was given by the Court of Cassation in a landmark judgment of 16 July 1986.

This decision, little known to the general public, is nevertheless essential for any owner or co-owner. It establishes a simple principle: the certificate of conformity, issued by the administration after verifying compliance with the building permit, does not prejudice the rights of third parties. In clear terms, even if the administration says 'yes, it complies with the permit', the builder remains bound to deliver a building that conforms to what he promised in the sale contract. A significant nuance, which has concrete implications for thousands of co-owners.

In this article, we will analyse this decision, understand why it was made, and above all, see what it changes for you, whether you are an owner, tenant or property professional. We will use concrete examples from Montpellier and Lodève to illustrate our point. Ready to learn more? Let's go.

The Facts: A Story Like Many Others Every Day

Imagine a property developer, Company X, which decides to build a multi-occupancy building in Montpellier, in the Aubes district. The building permit was obtained in 1975, amended in 1977. The work progresses, and in 1979, the flats are delivered to the first buyers. But quickly, defects appear: water seepage through the roofs, cracks in load-bearing walls, fixtures and fittings not conforming to the sale plans. The co-owners' association, representing the owners, sues the builder to obtain the necessary remedial work.

The builder defends himself by producing a certificate of conformity issued by the town hall, attesting that the building complies with the building permit. According to him, this document proves that everything is in order and that he has no further obligations. But the association retorts that the certificate only concerns administrative compliance, not contractual compliance. In other words, the builder promised specific features (size, materials, equipment) in the sale contracts and he must respect them, regardless of what the administration says.

The case comes before the Court of Cassation, which must decide: can the certificate of conformity exonerate the builder from his contractual liability? On 16 July 1986, the High Court delivers its judgment: no. It quashes the decision of the Court of Appeal, which had ruled in favour of the builder, and remits the case. For the judges, the certificate of conformity does not prejudice the rights of third parties, i.e. the buyers. They can still prove that the building does not conform to the contractual specifications and claim remedial work or damages.

The Reasoning of the Court — Analysed

To understand this judgment, we must go back to the legal basis. The Court of Cassation relies on Article 1240 of the Civil Code (formerly 1382), which provides that 'any act of a person which causes damage to another obliges the person by whose fault it occurred to make reparation'. Here, the builder committed a fault by not delivering a building conforming to his contractual commitments. The certificate of conformity does not erase this fault.

But more specifically, the Court recalls that the certificate of conformity is an administrative act attesting that the works comply with the building permit. It does not guarantee that the builder has fulfilled his contractual obligations towards the buyers. These two things are distinct. In other words, the administration checks compliance with planning law (height, surface area, layout), not the quality of materials or the living space promised in the contract.

What few people know is that this decision is a confirmation of an already established principle. The Court of Cassation does not innovate; it reaffirms that the contract is law between the parties (Article 1103 of the Civil Code). The builder cannot hide behind an administrative paper to escape his responsibilities. However, note that the certificate of conformity still has probative value, but it is not sufficient to prove that the building is perfect. The co-owners must provide other evidence: bailiff's reports, expert opinions, contractual plans, etc.

undefined, I have come across cases where developers tried to rely on the certificate of conformity to refuse remedial work. But this judgment cuts the ground from under their feet. The trial courts (tribunals, courts of appeal) must examine the reality of the contractual non-conformities, without being impressed by the town hall's stamp.

What This Changes for You — Concretely

So, how should you react if you are in a similar situation? Let's take concrete examples.

For a co-owner in Montpellier: You have just bought a flat in a new building, rue de la Loge. The sale plan mentions a surface area of 70 m², but after measurement, you find that it is only 65 m². The developer relies on the certificate of conformity. Thanks to this judgment, you can bring an action for contractual liability to obtain a price reduction or damages. The certificate does not protect him.

For a landlord owner in Lodève: You bought a studio in a new development to rent it out. The joinery is of poor quality, leading to heat loss and high energy bills. The builder tells you that everything complies with the permit. You can demand the replacement of the joinery, based on the sale contract which promised double glazing. The certificate of conformity does not prevent you from acting.

For a buyer under VEFA (Sale in the Future State of Completion): You sign a contract for a flat in Montpellier, with high-end features (parquet flooring, air conditioning). At delivery, the parquet is of inferior quality and the air conditioning is absent. The developer invokes the certificate of conformity. You can refuse delivery and demand the performance of the promised features. The 1986 judgment is your shield.

In practice, if you are in this situation, you must act quickly. The limitation periods (time limits to take legal action) are 5 years from delivery for apparent defects, and 10 years for latent defects (decennial liability). Do not wait. Have the non-conformities recorded by an expert or bailiff, and contact a lawyer lawyer.

Four Tips to Avoid This Type of Dispute

• Carry out a detailed inventory at delivery: Before signing the delivery report, inspect each room, measure the surfaces, check the materials and equipment. If something is wrong, mention it in writing and take photos. Prevention is better than cure.
• Keep all contractual documents: Sale plans, descriptive notice, reservation contract, everything that describes the promised features. These documents will be your best weapons in the event of a dispute. Keep them safely.
• Do not accept the certificate of conformity as absolute proof: If the builder relies on it, remind him of this Court of Cassation judgment. The certificate only proves compliance with the building permit, not with the contract. Insist on the necessary checks.
• Consult a lawyer at the first signs of non-conformity: Do not let it drag on. The limitation periods run quickly. A lawyer will help you gather evidence, assess your chances, and take action if necessary. An early consultation can save you months of proceedings.
• Consider an interim expert's report: If the disagreement persists, you can ask the interim judge to appoint a judicial expert to record the non-conformities. This procedure is quick and allows the evidence to be preserved.

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Further Analysis: Related Case Law and Developments

This 1986 decision is part of a consistent line of case law from the Court of Cassation. Already, in a judgment of 3 June 1981 (No. 80-10.456), the Court had held that the certificate of conformity does not bind the civil judge, who can freely assess the conformity of the building with the contractual provisions. More recently, in a judgment of 5 July 2018 (No. 17-17.281), the Court confirmed that the certificate of conformity is not an obstacle to an action under the decennial liability for defects affecting the building.

The courts are therefore very clear: the certificate of conformity is an administrative document, not a blank cheque for the builder. The trend is even towards strengthening the protection of buyers. In 2023, the Elan law (Evolution of Housing, Development and Digital Technology) increased the information obligations of developers, particularly regarding the characteristics of homes. This goes in the same direction as the 1986 case law: the contract takes precedence over the administrative authorisation.

For the future, we can expect judges to be increasingly vigilant about contractual conformity, especially in a market where property prices are high and buyers are demanding. The certificate of conformity will never be able to serve as a cover for questionable practices.

What You Must Absolutely Remember

FAQ: 5 Essential Questions

1. Does the certificate of conformity protect me as a builder? No, it does not protect you against claims from buyers for contractual non-conformity. You must deliver what was promised, otherwise you incur liability.
2. Can I refuse delivery if the building does not conform to the contract? Yes, you can refuse delivery and demand the performance of the work. The certificate of conformity does not oblige you to accept a non-conforming dwelling.
3. What are the time limits for taking action? For apparent defects (non-conformities visible at delivery), you have 5 years from delivery. For latent defects (serious hidden defects), the decennial guarantee applies for 10 years.
4. What should I do if the builder relies on the certificate of conformity? Reply that the 1986 Court of Cassation judgment clearly states that the certificate does not prejudice your rights. Consult a lawyer to take action.
5. What is the cost of legal action? Costs vary: lawyer's fees (often €1,500 to €5,000 depending on complexity), expert fees (€800 to €2,000), and possible court costs. But a successful action can save you much more (remedial work, price reduction).

Are you in a similar situation? A first 30-minute consultation with Maître Zakine (€45) could save you months of proceedings — and often much more. Book an appointment →