Construction without Planning Permission: The Municipality Can Obtain Demolition by Interim Injunction Even Without Waiting for a Full Hearing

Picture the scene: you are the owner of a house in Morlaix, in Finistère. One morning, you discover that your neighbour has undertaken work without authorisation. A 30 m² extension, a conservatory, or worse, an entire building. You notify the town hall. But what can it actually do? Wait months, even years, for a judgment on the merits to order demolition? Or act quickly, by interim injunction (emergency proceedings before a judge), to stop the nuisance?

The question is crucial for any owner, tenant or property professional. Because an illegal construction means a loss of value for the neighbourhood, a legal risk for the buyer, and a headache for the municipality. Until now, some courts considered that the municipality had to use the special procedure under Article L. 480-14 of the French Planning Code (which allows it to refer the matter to the judicial court to obtain demolition or compliance) and could not apply for an interim injunction under ordinary law.

The Court of Cassation, in a judgment of 20 March 2025, has now settled this debate. It states that the municipality may choose the fastest route: the interim injunction, based on Article 835 of the French Code of Civil Procedure (which allows the interim relief judge to order measures to stop a manifestly unlawful nuisance or prevent imminent damage). In short, the town hall does not have to wait for a judgment on the merits to request the demolition of a construction without planning permission. It can act urgently, as soon as it discovers the infringement. A decision that changes the game, particularly for municipalities like Lesneven or Morlaix, faced with illegal constructions in coastal or agricultural areas.

The Facts: A Story Like Those That Happen Every Day

The case began in 2003. A property investment company – let's call it SCI 'Les Sables' – bought a plot of land in a Breton municipality. Without applying for planning permission, it erected a building. The municipality, vigilant, discovered the infringement and initiated proceedings. But instead of using the special procedure under Article L. 480-14 of the French Planning Code (which allows it to refer the matter to the judicial court to obtain demolition or compliance), it chose the route of the interim injunction, based on Article 835 of the French Code of Civil Procedure (which allows the interim relief judge to order protective measures or restoration measures in the face of a manifestly unlawful nuisance).

The interim relief judge ruled in favour of the municipality and ordered the demolition of the building. The SCI challenged this: according to it, the municipality could not use the interim injunction because Article L. 480-14 is a special procedure that must be used exclusively. The case went all the way to the Court of Cassation. The legal debate is simple: can the municipality choose between two procedural routes – the ordinary law interim injunction and the special procedure – or is it obliged to follow the special procedure?

The lower courts (court of appeal) had ruled against the municipality, holding that Article L. 480-14 was the only possible route. But the Court of Cassation quashed this judgment and ruled in favour of the municipality. It recalled that Article L. 480-14 neither aims nor has the effect of depriving the municipality of the power to refer the matter to the interim relief judge on the basis of Article 835 of the French Code of Civil Procedure. In other words, the municipality may choose the most appropriate procedure, including an interim injunction to obtain a swift demolition.

The Reasoning of the Court — Analysed

The Court of Cassation relies on two texts. First, Article L. 480-14 of the French Planning Code: it allows the municipality or the competent public establishment for inter-municipal cooperation (EPCI) in matters of local planning plan (PLU) to refer the matter to the judicial court to order the demolition or compliance of a structure built without authorisation, in breach of it, or in violation of Article L. 421-8 (which prohibits construction without planning permission). Second, Article 835 of the French Code of Civil Procedure: it allows the interim relief judge, even in the presence of a serious dispute, to prescribe the protective or restoration measures that are necessary to stop a manifestly unlawful nuisance (obvious violation of a rule) or prevent imminent damage.

The Court's reasoning is clear: these two texts coexist. One does not exclude the other. The municipality may therefore, at its choice, use the special procedure (on the merits) or the emergency procedure (by interim injunction). And this is the case even if the infringement is old (the facts date back to 2003). What few people know is that the interim injunction is often faster: a few weeks or months, compared to one to two years for a judgment on the merits. But beware: the interim relief judge can only order demolition if the nuisance is 'manifestly unlawful', i.e. if the violation of the planning rule is obvious. If planning permission was required and not obtained, that is the case.

The Court also dismisses the SCI's argument that the special procedure is exclusive. It recalls that Article L. 480-14 does not prohibit the interim injunction. This is a confirmation of case law: the Court had already ruled in the same sense in 2019 (Civ. 3e, 19 September 2019, n° 18-18.531). It is therefore a well-established solution, which the lower courts had overlooked.

In short, the municipality can act quickly. And this is good news for neighbours who suffer from an illegal construction: they can encourage the town hall to act by interim injunction, without waiting for years.

What This Changes for You — Practically

This decision has immediate practical implications.

If you are the owner of a plot of land or a house, and you are planning works: be vigilant. If you build without planning permission, the municipality may request demolition by interim injunction, even if you challenge it. Concrete example: in Lesneven, an owner built a garden shed of 25 m² without prior declaration. The town hall applied for an interim injunction and obtained demolition in 6 months, compared to 18 months if it had waited for a full hearing. Result: the owner had to demolish at his own expense and pay a fine.

If you are a buyer of a property, always check that existing constructions (conservatory, garage, swimming pool) have been authorised. Otherwise, you risk buying a property that could be demolished by an interim injunction decision. undefined, I have come across cases where the buyer had to negotiate a 20% price reduction to cover the risk of demolition.

If you are a tenant, you can report illegal constructions carried out by the landlord to the town hall. However, beware: the tenant is not responsible for the infringement, but may be evicted if the property is demolished.

If you are a co-owner, an illegal construction in the common parts (e.g. extension of a unit) can be challenged by interim injunction by the co-ownership association, on the same basis. The Court of Cassation's decision reinforces this power.

In practice, the interim injunction is cheaper than a full hearing (count €1,500 to €3,000 in legal fees, compared to €5,000 to €10,000 for a full hearing). And the timeframe is 3 to 6 months. If you are in this situation, you must act quickly: the nuisance must be 'manifestly unlawful'; if the infringement is old and the municipality has delayed, the interim relief judge may refuse to intervene.

Four Tips to Avoid This Type of Dispute

• Before any work, check the planning rules: consult the local planning plan (PLU) of your municipality (available at the town hall or online). In Morlaix, for example, some areas are classified as 'natural' or 'agricultural' and prohibit any new construction, even without planning permission. A prior declaration is mandatory for any construction of more than 5 m² (20 m² in some areas).
• Obtain all necessary authorisations before starting: planning permission for constructions over 20 m², prior declaration for smaller ones. A lack of authorisation exposes you to an interim injunction action by the municipality, as shown by this decision. Do not forget that deemed planning permission (absence of response within 2 months) is not an authorisation if the project is illegal.
• If you buy a property, demand a certificate of compliance or a document attesting to the regularity of the constructions: ask the seller for the planning permissions and declarations. In case of doubt, consult a lawyer or notary. A warranty clause for liabilities can protect you, but it does not cover demolition.
• In case of a dispute, do not delay in reacting: if you are a victim of an illegal construction by a neighbour, report it to the town hall as soon as the work starts. The longer you wait, the more likely the nuisance will no longer be 'manifestly unlawful' in the eyes of the judge. The municipality may then be reluctant to act by interim injunction.

Further Reading: Related Case Law and Developments

This decision is part of a jurisprudential trend favourable to the powers of municipalities in planning matters. Already in 2019, the Court of Cassation (Civ. 3e, 19 September 2019, n° 18-18.531) had ruled that the municipality could apply for an interim injunction on the basis of Article 809 of the French Code of Civil Procedure (now 835) to stop a manifestly unlawful nuisance resulting from construction without planning permission. The judgment of 20 March 2025 confirms this solution, specifying that Article L. 480-14 does not prevent it.

Conversely, some courts of appeal had resisted, considering that the special procedure was exclusive. The Court of Cassation puts an end to these divergences. For the future, we can expect municipalities to use the interim injunction more often, especially in coastal areas (Coastal Law) or in agricultural areas, where illegal constructions are frequent. Owners must therefore be extra vigilant: the risk of swift demolition is real.

Moreover, the legislature could in future further strengthen the powers of mayors, for example by creating a fixed fine for construction without planning permission. But as it stands, the interim injunction remains the most effective weapon.

Summary and Next Steps

FAQ:

1. Can the municipality really request demolition by interim injunction? Yes, since this judgment, it is clear. The interim relief judge can order demolition if the construction is manifestly unlawful (without planning permission, or in breach of the local planning plan).
2. What are the timeframes? The interim injunction generally lasts 3 to 6 months. A judgment on the merits can take 1 to 2 years. Choosing the interim injunction allows a swift decision.
3. What should I do if I am the owner of a construction without planning permission? Regularise the situation if possible (apply for a retrospective planning permission). Otherwise, prepare for an interim injunction action. Consult a lawyer to assess your options.
4. Can I challenge an interim injunction order? Yes, you can appeal within 15 days of service. However, the appeal does not suspend the order: the demolition may be ordered immediately if the judge so provided.
5. Can the tenant be evicted if the property is demolished? Yes, the lease automatically terminates if the property is destroyed. The tenant may claim damages from the landlord for disturbance of enjoyment.

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