Change of Use Without Works: Preliminary Declaration Mandatory Since 2007

Imagine: you own a former hotel in Saint-Vincent-de-Tyrosse, on the Landes coast. Due to a lack of customers, you decide to convert the rooms into furnished flats. You do not touch any partition walls, you just change the use. No works, so no authorisation needed, you think. Serious mistake.

This situation, experienced by a Landes landlord, led to a criminal conviction upheld by the Court of Cassation on 3 September 2024. The issue is simple: since 2007, any change of use (converting a shop into a dwelling, an office into a home, etc.) must be declared to the town hall, even without a single hammer blow.

But what does this actually change for you? Do you need to declare the conversion of your garage into a bedroom? And what if you rent out a gîte in a renovated barn? This decision clarifies the rules and increases penalties. Analysis.

The facts: a story that happens every day

Mr X, owner of a hotel in Saint-Vincent-de-Tyrosse, sees his business decline. In 2018, he decides to convert the 15 hotel rooms into rental dwellings. He carries out no works: the rooms already have sanitary facilities, he just changes the locks and signs leases. No planning permission, no preliminary declaration. For him, no works, no formalities.

But a neighbour, annoyed by the increased comings and goings, reports the situation to the town hall. The planning department notes that the hotel has become a residential building: change of use (from hotel to dwelling, that is, from the 'commercial' category to 'residential'). However, this change should have been the subject of a preliminary declaration (DP) before any letting.

The owner is prosecuted for an offence under the planning code (execution of works without authorisation). He argues the absence of works and disputes the classification of change of use. The criminal court of Mont-de-Marsan convicts him in 2022 to a fine of €10,000 and an order to restore the premises under a penalty payment. The Court of Appeal of Pau confirms in 2023. Mr X appeals to the Court of Cassation.

The Court of Cassation dismisses his appeal on 3 September 2024. It recalls that Article L. 421-1 of the Planning Code subjects to authorisation (planning permission or preliminary declaration) all works, installations and changes of use of an existing building. And Article R. 421-17 specifies that changes of use, even without works, are subject to a preliminary declaration since 1 October 2007. In other words, regardless of the extent of the works: the mere change of use is sufficient to trigger the obligation to declare.

The court's reasoning — analysed

The Court of Cassation relies on two essential texts:

• Article L. 421-1 of the Planning Code: 'Constructions, even those without foundations, must be preceded by a planning permission [...] or a preliminary declaration.' The law includes within this obligation changes of use of existing constructions.
• Article R. 421-17: It lists the cases where a preliminary declaration suffices (instead of planning permission). Among them: the change of use of an existing construction between the different uses defined by the national planning regulations (dwelling, commerce, craft industry, etc.), whether or not there are works.

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In plain English, the owner should have filed a preliminary declaration at the town hall before renting out the rooms as dwellings. Failure to declare constitutes a criminal offence, punishable by a fine (up to €120,000 and 6 months' imprisonment for individuals, under Article L. 480-4).

The judges dismissed the argument of the absence of works: the law is clear, the change of use suffices. They also rejected the challenge to the classification: the conversion of a hotel (commercial) into dwellings (residential) is indeed a change of use, even if the structure remains identical.

This reasoning confirms consistent case law since 2007: the use of a building is an autonomous legal concept, distinct from works. The courts are increasingly strict, especially in tourist areas like the Landes, where conversions of hotels into residences are frequent.

undefined, I have encountered cases where owners in Parentis-en-Born converted their garage into a studio without declaration. Result: fine and obligation to restore the property, with legal and procedural costs often exceeding €5,000. A simple preliminary declaration (cost: €0, just the time to fill in the form) would have avoided all that.

What this changes for you — concretely

For landlord owners: If you convert a commercial premises, garage, barn or any other building into a dwelling, you must file a preliminary declaration, even without works. Failure to declare can result in a fine (up to €120,000) and an obligation to restore the premises to their original state. Example: in Parentis-en-Born, an owner converted an old workshop into two flats without declaration. He was fined €8,000 and ordered to demolish the added partitions, costing him €15,000 in works.

For tenants: Check that your dwelling has been properly declared. If you rent a former shop converted without authorisation, you could be evicted for non-compliance with planning rules. Additionally, the lease may be annulled for lack of conformity. If in doubt, ask the owner for the preliminary declaration certificate or planning permission.

For buyers: Before buying a property, check its use in the notarial deeds and the planning certificate. An undeclared change of use can expose you to legal action and the inability to let or resell the property. Have a professional diagnosis carried out.

For co-owners: If a co-owner converts their lot (e.g., a bicycle storage room into a dwelling) without authorisation, the management company can act to stop the infringement. The co-ownership could be held jointly liable for the fines.

Four tips to avoid this type of dispute

1. Before any change of use, file a preliminary declaration at the town hall. The form (Cerfa 13703*09) is simple: you describe the project, the area, the current and future use. The town hall has one month to respond. If it does not respond, it is tacit approval. This service is free.
2. Consult your municipality's Local Planning Plan (PLU). In Saint-Vincent-de-Tyrosse as in Parentis-en-Born, the PLU may prohibit certain changes of use (e.g., to protect shops in the town centre). If your project contravenes the PLU, the declaration will be refused.
3. Keep a record of the authorisation. Keep the acknowledgement of receipt of the declaration and, if applicable, the order of non-opposition. These documents protect you in the event of a later inspection (even years later).
4. Use a professional for complex cases. If you are unsure about the use (e.g., is a gîte a dwelling or a commercial premises?), an architect or lawyer lawyer can advise you. The investment (a few hundred euros) is trivial compared to the risks.

Further reading: related case law and developments

This decision follows a strict line of the Court of Cassation. Already in 2019 (Civ. 3e, 6 June 2019, no. 18-16.781), it held that the conversion of a commercial premises into a dwelling, without works, fell within the scope of the preliminary declaration. In 2021 (Civ. 3e, 10 March 2021, no. 20-10.824), it specified that a change of use was established even if the premises were already used as dwellings in fact, without authorisation.

The trend is towards stronger controls: town halls, especially in pressured areas like the Landes coast, track undeclared changes of use to combat substandard housing and preserve commercial balance. In the future, we can expect penalties to be increased, notably through higher fines and systematic restoration obligations.

Frequently asked questions

Q: Can I convert my garage into a bedroom without a declaration?
A: No. A garage is an annex (use 'garage'), a bedroom is a dwelling. This is a change of use subject to a preliminary declaration, even without works.

Q: What should I do if I have already changed the use without a declaration?
A: Regularise as soon as possible by filing a preliminary declaration. If the town hall accepts it, you will avoid a fine. If refused, you must restore the property. Consult a lawyer to assess the risks.

Q: What are the time limits for obtaining a preliminary declaration?
A: The town hall has one month to process your file. If it remains silent, the authorisation is deemed granted. But beware: if the project contravenes the PLU, the time limit may be extended.

Q: Do I need to declare the conversion of a hotel into dwellings if I keep some hotel rooms?
A: Yes, if only part changes use. The declaration must cover the affected areas. It is better to declare the entire project to avoid disputes.

Q: What are the risks if I do not declare?
A: Criminal fine up to €120,000, obligation to restore the property (sometimes with a penalty payment of €500 per day of delay), and inability to sell or let the property without regularisation. Not to mention legal and procedural costs.

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