Construction without planning permission: subsequent regularisation does not eliminate the offence

Imagine: you are the owner of a house in Ornans, in the Doubs. You decide to extend your living room without applying for planning permission, thinking you can regularise it later. Work progresses, the roof is on. But a neighbour reports you to the town hall. You then submit a planning application, which is granted. Phew, you're safe? Not so sure. The Court of Cassation, in a decision of 6 January 1965, ruled: the offence has already been committed. Planning permission granted after the start of work does not erase the offence. This decision, although old, remains an absolute reference in French planning law. But what does it actually mean for you, as owner, tenant or property professional? Let's delve into this case.

The facts: a story like many that happen every day

Mr Maurice, an owner in Paris, undertakes construction work without having obtained planning permission beforehand. Like many, he thinks he can regularise his situation afterwards. During the works, the planning authorities discover the offence. Prosecuted before the criminal court, Mr Maurice is fined 2,000 francs (a significant sum at the time). He appeals, but the Paris Court of Appeal upholds the conviction on 17 April 1964. Mr Maurice then appeals to the Court of Cassation. His main argument: he eventually obtained planning permission after the start of the work, which should, according to him, nullify the offence. The Court of Cassation does not follow him. It quashes the judgment on another point (the classification of the offence), but confirms the principle: the offence of building without planning permission is committed as soon as the work is undertaken, and planning permission granted later has no retroactive effect to erase the offence. In short, you cannot build first and ask for forgiveness afterwards.

The reasoning of the court — dissected

The Court of Cassation relies on Article 84 of the Town Planning Code (now codified in Articles L. 421-1 et seq.). This provision states that any construction must be preceded by planning permission. The offence is constituted by the mere fact of undertaking the work without such permission. It does not matter that permission is obtained later: the offence is instantaneous, it occurs at the moment the first stone is laid. The Court rejects the idea of a "criminal regularisation". In other words, obtaining planning permission may avoid demolition or an administrative fine, but it does not erase the criminal fault. undefined, I have come across cases where owners in Audincourt thought they were doing the right thing by regularising afterwards, and ended up with a fine and a criminal record. However, note that this decision has been nuanced over time. Today, courts may take regularisation into account to reduce the penalty, but the principle remains: the offence exists. What few people know is that this rule also applies to façade alterations or changes of use (e.g. converting a garage into a dwelling).

What this means for you — practically

For an owner wishing to carry out works, this decision means you must obtain planning permission before starting. If you are a landlord and your tenant carries out works without authorisation, you may be held liable as owner. For a buyer, check that previous works were authorised: a construction without planning permission may give rise to latent defects or obligations to restore the property. Concrete example: in Audincourt, an owner bought a house with an unauthorised extension. The seller had obtained planning permission after the works, but the new buyer was prosecuted for the continuing offence. He had to pay a €5,000 fine and demolish the extension. If you are in this situation, you should consult a lawyer lawyer to assess the risks. In a condominium, works without planning permission in common areas may render the managing agent liable. The limitation period for the offence is 6 years (Article 8 of the Code of Criminal Procedure), but the offence may be discovered long after.

Four tips to avoid this type of dispute

• Obtain all permits before starting work. Even for a small extension or garden shed, check whether planning permission is required. A preliminary declaration may suffice for small constructions, but it must be filed with the town hall.
• Consult the local planning plan (PLU) of your municipality. Rules vary by zone: in Ornans, for example, some areas are protected. The town hall's planning department can advise you free of charge.
• If in doubt, apply for a planning certificate. This official document tells you whether a project is feasible and what authorisations are needed. It provides legal certainty.
• Never rely on retrospective regularisation. Even if you obtain planning permission afterwards, you risk criminal prosecution. Administrative regularisation does not cover the criminal offence.
• If you buy a property, have the conformity of existing constructions checked. A technical survey may reveal unauthorised works. Require the seller to provide planning documents.

Further reading: related case law and developments

This 1965 decision has been confirmed several times. For example, the Court of Cassation, in a judgment of 12 February 1997 (No. 95-85.127), reiterated that subsequent regularisation does not erase the offence, even if planning permission is granted before the judgment. However, a decision of the Conseil d'État of 27 July 2015 (No. 373.260) nuanced the administrative aspect: planning permission obtained afterwards can regularise the construction from a civil perspective, but not from a criminal one. The current trend of the courts is to sanction more severely constructions without planning permission in protected areas (coastal, mountain). For the future, the ALUR law of 2014 strengthened controls and sanctions. In summary, the 1965 rule is still relevant: do not build without planning permission, even if you think you can regularise.

Key points to remember

• When is the offence committed? As soon as work begins, without planning permission.
• Does planning permission obtained afterwards erase the offence? No, the criminal offence remains.
• What are the possible penalties? Fine up to €6,000 per m² built, demolition, imprisonment in some cases.
• Can I regularise administratively? Yes, but this does not protect against criminal prosecution.
• What should I do if I am prosecuted? Consult a lawyer specialising in planning law.

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