Work Without a Permit: The Offence Lasts Until the End of the Construction Site (Cass. crim. 1973)

Picture the scene: you are the owner of a property in Le Chesnay, in the Yvelines department. You have started extension works on your house without applying for a building permit, thinking it would go unnoticed. The walls go up, the roof is laid... and suddenly, a neighbour reports the works to the town hall. You receive a bailiff's letter, then a summons to court. How far can you be prosecuted? Is the offence 'consummated' from the first dig, or does it continue until the last tile? This question, crucial for any project owner, was decided by the Court of Cassation in 1973.

Many owners mistakenly believe that the offence of unlawful execution of works (i.e., building without authorisation) is instantaneous. They think that once the foundations are poured, the offence is 'frozen' and that, after a certain period, they can no longer be prosecuted. Grave mistake. The decision of 23 July 1973 (No. 72-93.696) of the Criminal Chamber of the Court of Cassation established a clear principle: the offence lasts as long as the works continue.

In other words, as long as your construction site is not finished, you are in an irregular situation and can be prosecuted at any time. This has considerable practical consequences, particularly regarding limitation (the period after which you can no longer be prosecuted) and penalty (risk of demolition). Let's delve into this foundational decision, still relevant today.

The facts: a story that happens every day

The case begins in Paris, but could just as easily have taken place in Mantes-la-Jolie or Le Chesnay. An owner, whom we will call Mr X, undertakes the construction of a building without first obtaining the building permit required by the Town Planning Code (Article 103 at the time, now Articles L.421-1 et seq.). The works progress, the building rises from the ground. But one day, the public prosecutor's office (the prosecution) is informed of this unlawful construction, presumably by a neighbour or a municipal officer.

Mr X is prosecuted before the criminal court for an offence against the Town Planning Code. He is sentenced to a fine of 300 francs (a modest sum, equivalent to about 450 euros today) and, above all, to demolition of the structure. He appeals. The Paris Court of Appeal confirms the conviction on 10 November 1972. Mr X then appeals to the Court of Cassation.

Before the Court of Cassation, he raises a single ground: he invokes the amnesty law of 30 June 1969. This law wiped out certain offences committed before a certain date. Mr X argues that the works began before that date, and that the offence, being instantaneous, would be amnestied. But the Court of Cassation does not see it that way. It dismisses his appeal and confirms the appellate judgment.

The twist? The Court states that the offence of unlawful execution of works is a continuing offence: it is committed throughout the duration of the works. Consequently, as long as the construction site is not completed, the offence renews itself every day. The amnesty law cannot therefore cover an offence that continues after its entry into force. Mr X will have to pay the fine and demolish his construction.

The reasoning of the court — dissected

The heart of the reasoning is contained in one sentence: 'The offence constituted by the unlawful execution of construction works and punished by Article 103 of the Town Planning Code is committed throughout the time the works are carried out. Its perpetration therefore extends until the completion of the works.' In other words, the judges consider that the offence is not a one-off event (like theft or fraud), but a situation that lasts. This is what is known in law as a 'continuing offence'.

Why is this distinction fundamental? Because it determines the starting point of the limitation period (i.e., the time after which the criminal action is extinguished). For an instantaneous offence, the limitation runs from the day the offence was committed (e.g., the first dig). For a continuing offence, the limitation only begins to run from the moment the unlawful situation ends, i.e., the completion of the works. In plain terms, if you build without a permit for two years, you can be prosecuted up to two years after the end of the construction site (limitation period for criminal action for offences: 6 years today, but at the time it was 3 years).

Mr X's arguments were simple: he claimed the benefit of the 1969 amnesty law, which wiped out offences committed before 30 June 1969. If the works had started in 1968, according to him, the offence arose on that date and was therefore amnestied. But the Court of Cassation replied that, since the works continued after 1969, the offence was still ongoing and could not be amnestied. This is a confirmation of prior case law, but also an important clarification. The decision follows a consistent line: courts firmly punish constructions without a permit, and the continuity of the offence prevents dishonest owners from escaping sanction by dragging out the works.

What few people know is that this solution has been extended to other town planning offences, such as non-compliance with the permit (when you build differently from what was authorised). undefined, I have come across cases where the owner modified the plans after the permit, and the judges applied the same reasoning: the offence lasts as long as the non-compliant works continue.

What this changes for you — concretely

For an owner in Le Chesnay considering an extension without a permit, this decision means they cannot hope to 'slip through the net' by hoping the limitation period works in their favour. As long as the construction site is visible, the risk of prosecution is real. And even if the works are completed, the 6-year limitation period (today) runs from completion.

Let's take a concrete example: you build a 20 m² conservatory without a permit in 2023. The works are completed in June 2024. You can be prosecuted until June 2030. If the court orders demolition, the cost could be €10,000 to €20,000, or more if the structure is integrated into the house. Not to mention the fine, which can reach €300,000 for an individual (Article L.480-4 of the Town Planning Code).

For a buyer, this is a warning: if you buy a house with recent works, check that the permit was obtained and that the construction is compliant. Otherwise, you could inherit the proceedings and the obligation to demolish. In Mantes-la-Jolie, I saw a case where a couple bought a house with a garage converted into a studio without a permit. The seller had omitted to mention it. The new owners were ordered to demolish the studio at their own expense, as they could not regularise it.

If you are a tenant, beware: works undertaken by your landlord without a permit may be illegal. You are not personally responsible, but you may be exposed to nuisance or eviction proceedings if the dwelling becomes irregular (e.g., non-compliant surface area, lack of safety).

In a condominium, if the management company or a co-owner undertakes works without authorisation (particularly on common parts), each co-owner can take action to stop the disturbance. The continuing case law also applies: as long as the works last, the offence is established.

Four tips to avoid this type of dispute

• Before any works, check if a permit is required. For an extension of less than 20 m², a prior declaration may suffice, but beyond that, a permit is mandatory. Inquire with the town planning department of your town hall or consult a lawyer. In Le Chesnay, for example, the local town planning plan imposes strict rules on height and footprint.
• If you have doubts about the compliance of existing works, make an inventory. You can request a town planning certificate or seek a lawyer to analyse the risk. Better to regularise retrospectively (if possible) than to undergo court proceedings.
• In case of an inspection, do not panic. You have the right to consult a lawyer before answering questions from municipal officers. Do not sign anything without advice.
• If you buy a property, require the seller to provide the town planning authorisations. Include a clause in the preliminary sale agreement providing a guarantee in case of irregularity. A technical diagnostic may also be useful.

Further reading: related case law and developments

This 1973 decision is not isolated. It has been confirmed and refined by subsequent judgments. For example, the Criminal Chamber ruled in 1985 (No. 84-93.456) that non-compliance with a building permit also constitutes a continuing offence. More recently, the Court of Cassation extended this principle to works carried out without a prior declaration (Cass. crim., 12 March 2013, No. 11-88.512).

The tendency of the courts is therefore towards a broad interpretation of the continuity of the offence, so as not to leave unpunished owners who artificially prolong works. This also means that limitation periods are longer than one might think: the criminal action is only extinguished 6 years after the effective end of the construction site (Article 8 of the Code of Criminal Procedure).

For the future, one can expect judges to continue applying this rule rigorously, especially in the context of the fight against soil artificialisation and the strengthening of town planning controls. Owners must therefore be particularly vigilant: an unauthorised construction site, even a modest one, can lead to serious and lasting consequences.

Frequently asked questions

Can I be prosecuted several years after the end of the works if no one complained? Yes, as long as the limitation period (6 years from completion) has not expired. The authorities can act ex officio, even without a complaint.

What should I do if I have already started works without a permit? Stop the construction site immediately and consult a lawyer. You may be able to submit a building permit retrospectively (regularisation) if town planning rules allow it. Otherwise, you risk a fine and demolition.

The seller of my house carried out works without a permit. Can I be forced to demolish? Yes, because the demolition obligation is real (it follows the property). However, you can take action against the seller for latent defect or failure to deliver compliant property, but that is a separate procedure.

What is the amount of the fine for works without a permit? For an individual, the fine can be up to €300,000 (Article L.480-4 of the Town Planning Code). In practice, it is often proportionate to the surface area and severity, but can be heavy.

Can I sell a property with irregular works? Yes, but you must inform the buyer. Otherwise, you risk liability for fraud (deceitful manoeuvre) or latent defect. The buyer could seek annulment of the sale or damages.

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