Illegal construction: demolition applies even to the new purchaser (Cass. crim., 9 Sept. 2009)

Imagine: you buy a beautiful villa with a view of the Étang de Thau, in Sète. Everything seems in order. A few months after the purchase, you receive a letter from the court: the construction was built without a permit by the previous owner, and a demolition order has been made. You must raze your house, at your own expense. Unfair? Yet this is what the Court of Cassation confirmed in its judgment of 9 September 2009 (No. 07-20.189).

The question every owner asks is simple: am I responsible for illegalities committed before my purchase? The judges' answer is clear: yes, if the construction was irregular and demolition was ordered before the sale. The measures of demolition and regularisation provided for in Article L. 480-5 of the Town Planning Code are not criminal penalties (which could only affect the offender), but measures of a real nature: they attach to the property itself, regardless of who holds it.

In short, this decision protects the effectiveness of the fight against illegal constructions, but it traps unwary purchasers. In this article, I dissect the case, the judges' reasoning, and give you practical advice to avoid finding yourself in this situation. Because, in my practice, I have come across cases where the purchaser knew nothing about the irregular works carried out ten years earlier.

The facts: a story like many others

Mr X, owner of a villa in Montpellier, carried out extension works without obtaining the required building permit. The mayor drew up a report of the offence, and the criminal court fined Mr X and, above all, ordered the demolition of the illegal construction, in accordance with Article L. 480-5 of the Town Planning Code. Mr X appealed, then lodged an appeal in cassation. In the meantime, he sold the villa to Mrs Y. The latter, having become owner, argued that the demolition order could no longer be enforced against her since she had not been a party to the criminal proceedings. The lower courts rejected this argument, and the Court of Cassation confirmed.

The dispute therefore concerned the legal nature of the demolition measure: is it a personal penalty (which can only affect the convicted person) or a real measure (which follows the property)? The judges opted for the latter, relying on the wording of Article L. 480-5, which provides that demolition may be ordered "even in the absence of criminal proceedings". In other words, the legislature intended these measures to have a real scope, independent of the person of the owner.

What few people know is that the demolition order can be made even if the purchaser has committed no fault. The Court of Cassation held that it is not necessary to reiterate the decision against the new owner: it is opposable to them as of right from the pronouncement of the judgment. However, note: this opposability presupposes that the decision is final (no further appeal possible) before the sale. If the sale occurs while proceedings are ongoing, the purchaser may still intervene to defend their interests.

The court's reasoning — dissected

The Court of Cassation based its decision on Article L. 480-5 of the Town Planning Code (in the version then in force). This article provides that, in the case of construction without a permit, the court may order the demolition or regularisation of the building, "even if the construction is completed". The Court deduces that these measures do not constitute criminal penalties (which would be governed by the principle of personal liability for penalties, Article 121-1 of the Criminal Code), but measures of a real nature. Their objective is to restore town planning legality, regardless of the person who occupies or owns the property.

The high court also dismissed Mrs Y's argument that she should have been joined in the proceedings. It considered that the demolition order is opposable to any successive holder, without the need to reiterate it against them. This reasoning is part of consistent case law: restoration measures (demolition, regularisation, prohibition of occupation) are attached to the building, not the person. Thus, the purchaser cannot invoke their good faith to escape the obligation to demolish.

In this case, the court of appeal had found that it was technically possible not to demolish the villa, given the works carried out. But the Court of Cassation censored this assessment, considering that the technical possibility of not demolishing had to be established more solidly. In other words, the judge must verify whether regularisation is possible without demolition; if so, they may order it instead. But if regularisation is impossible, demolition is required, even if the new owner has done nothing wrong.

In other words, the case law distinguishes two stages: first, the court must consider whether regularisation is possible; if so, it may order it rather than demolition. If regularisation is not feasible, demolition is the only outcome. And this obligation falls on the current owner, whoever that may be.

What this means for you — practically

For landlord owners: if you rent out a property whose construction was irregular, you are obliged to demolish or regularise, even if the tenant is in place. undefined you must terminate the lease before the works, or compensate the tenant. Example: a villa in Montpellier rented for €1,200/month, with regularisation works costing €50,000. If you have to demolish, the total cost (demolition + partial reconstruction) could exceed €150,000.

For purchasers: before buying, demand the building permits and certificates of conformity. If you buy a property with an unauthorised extension, you risk demolition at your own expense. Concrete example in Sète: a purchaser bought a flat with a covered terrace without a permit. The seller had been ordered to demolish, but the purchaser had to enforce the decision. Cost: €8,000 for demolition, plus €3,000 in legal fees.

For tenants: you are not directly targeted by the demolition measure, but you may be evicted if the owner has to raze the property. You are entitled to notice and an eviction indemnity if the lease is terminated for this reason.

If you are in this situation, you must check whether the demolition order is final. If it is, you can no longer escape the obligation. However, if proceedings are ongoing, you can voluntarily intervene to present your arguments (for example, propose regularisation).

Four tips to avoid this type of dispute

• Hire a surveyor before purchase: to verify the conformity of constructions with the building permit and the local town planning plan. undefined, I came across a case in Montpellier where a purchaser discovered after the sale that the pool was built in a non-buildable zone. Cost of verification: €800, but it avoided a demolition costing €20,000.
• Require an eviction warranty in the sale deed: include a clause whereby the seller undertakes to indemnify you against any demolition action based on prior works. If the seller refuses, be wary.
• Consult the town planning department of the town hall: ask for a town planning certificate or an extract from the building permits register. This allows you to know whether works have been authorised. In Sète, the town hall provides this information free of charge by appointment.
• Check insurance policies: some building damage or legal protection insurance policies cover regularisation costs if the seller concealed the works. Ask your insurer.

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Further reading: related case law and developments

The solution in the judgment of 9 September 2009 follows earlier case law. As early as 1995, the Court of Cassation (Cass. crim., 21 June 1995, No. 94-82.467) held that demolition ordered under Article L. 480-5 is a real measure, opposable to the successive owner. The 2009 judgment confirms and specifies that the purchaser does not need to be joined in the initial proceedings.

More recently, the Court of Cassation (Cass. crim., 10 January 2017, No. 16-80.099) extended this principle to regularisation measures: the obligation to file a modified permit or carry out works may be imposed on the new owner, even if they did not participate in the proceedings. The trend is therefore consistent: judges prioritise the effectiveness of the town planning sanction over the protection of the good faith purchaser.

What this means for the future: if you buy a property with non-compliant works, you will not be able to invoke your good faith to escape demolition. The only possible escape is to prove that the demolition order was not final at the time of the sale, and to intervene in the proceedings to request an alternative regularisation.

Key points to remember

1. Demolition is a real measure: it follows the property, not the person. The purchaser is obliged to execute it, even if they committed no offence.
2. No need to reiterate the decision: the demolition order is opposable as of right to the new owner, without the need to serve them.
3. Check before buying: consult the building permit, certificate of conformity and local town planning plan. If in doubt, call in an expert.
4. If proceedings are ongoing: intervene voluntarily to defend your interests and propose regularisation instead of demolition.
5. Eviction warranty: include a clause in the sale deed to protect yourself.

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