In brief
Most works on a French house need permission from the mairie. A pool with a basin between 10 and 100 m² needs a déclaration préalable (DP); a larger one needs a permis de construire. An extension needs a DP up to 20 m², a limit raised to 40 m² in an urban zone of a commune with a plan local d'urbanisme (PLU); beyond that, a permis. The local PLU sets what may be built on each plot. On the Côte d'Azur coastal law, fire and landslide risk plans add further limits. Before buying a house with a pool or an extension, ask for the permits and the completion documents. This page is general information, not legal advice; an architect, the mairie or your notaire can confirm the position for a given property.
Start with the PLU
The PLU places every plot in a zone: U (urban), AU (to be urbanised), A (agricultural) or N (natural and forest). Each zone has its own rules on what may be built, how high, how far from the boundaries and how much of the plot may be covered. You can read the rules for any plot on the Géoportail de l'urbanisme or at the mairie.
For certainty before buying, ask the mairie for a certificat d'urbanisme:
| Certificate | What it gives | Mairie's time to reply |
|---|---|---|
| Certificat d'urbanisme d'information | The rules, taxes and easements that apply to the plot | 1 month |
| Certificat d'urbanisme opérationnel | Whether a specific project is feasible on the plot | 2 months |
Both are valid for 18 months and freeze the rules and tax rates for that period; neither is a permission to build.
Which permission for which work
| Work | Formality |
|---|---|
| Pool basin of 10 m² or less | None, except a DP in a protected area |
| Pool basin over 10 m² up to 100 m², uncovered or with a cover under 1.80 m high | Déclaration préalable |
| Pool basin over 100 m² or with a cover of 1.80 m or more | Permis de construire |
| Extension or veranda of more than 5 m² up to 20 m² | Déclaration préalable |
| Extension or veranda up to 40 m² in zone U of a PLU | Déclaration préalable, unless the house then exceeds 150 m² |
| Larger extensions | Permis de construire |
| Free-standing garden building under 5 m² | None |
| Garden building of 5 to 20 m² (40 m² in zone U) | Déclaration préalable |
| New windows, doors, façade renovation, roofing, external insulation, rooftop solar panels, air-conditioning or heat-pump units | Déclaration préalable |
| Walls of 2 metres or more | Déclaration préalable; in protected areas, walls of any height |
| Fences | Déclaration préalable in protected areas or where the commune requires it |
Protected areas include sites patrimoniaux remarquables, the surroundings of historic monuments and sites classés, where the Architecte des Bâtiments de France gives an opinion. When the total floor area after the works exceeds 150 m², the plans must be drawn up by an architect.
From application to completion
- File the application. Every commune must be able to receive applications online; individuals may still file on paper.
- Wait for the decision. A DP takes 1 month and a permis for a house 2 months, each from the date the file is complete; add a month in a protected area. If the mairie says nothing by the end of the period, permission is generally granted, but in some protected cases silence means refusal.
- Display the permission on a panel visible from the road for the whole of the works and at least two months.
- Allow for appeals. Since the law of 26 November 2025, a neighbour has one month from the first day of display to ask the mayor to reconsider and two months to go to court; the request to the mayor no longer extends the court deadline.
- Start within three years. A permission is valid for three years and lapses if works stop for more than a year; it can be extended twice by a year. Permissions issued between 2021 and May 2024 were given longer periods by a decree of 26 May 2025.
- File the opening of works (déclaration d'ouverture de chantier) before starting.
- File the completion declaration (DAACT) when the work is finished. The mairie then has three months to contest conformity (five months in a protected area or a zone covered by a risk prevention plan). Ask for the certificate of non-contestation afterwards.
Pools in particular
Safety. Every private in-ground pool that is not enclosed must have a standard safety device: a barrier (NF P90-306), an alarm (NF P90-307), a cover (NF P90-308) or an enclosure (NF P90-309). The fine for failing to fit one is €45,000. If you let the house, the device must work before the guests arrive; see our holiday letting guide.
Taxes. A new pool or extension carries the taxe d'aménagement. For 2026 the flat value is €251 per m² of pool basin and €892 per m² of floor area outside Île-de-France, with a 50% reduction on the first 100 m² of a principal residence, before the local rates are applied. It is declared on impots.gouv.fr within 90 days of completion. A pool must also be declared for taxe foncière within 90 days of completion; see our guide to French property taxes.
Water. In a drought, prefectoral orders restrict filling pools; at crisis level, filling or topping up a private pool is banned. At the end of September 2026, 43 communes of the Alpes-Maritimes were at crisis level. Check VigiEau before filling a new pool.
Coastal and hillside constraints
| Constraint | What it means |
|---|---|
| Loi Littoral, 100-metre strip | Outside built-up areas, building is prohibited within 100 metres of the shore |
| Loi Littoral, continuity | New building must adjoin existing towns and villages; only limited extension is allowed near the shore |
| Coastal footpath | A pedestrian easement three metres wide runs along the shore; it cannot pass within 15 metres of houses built before 1976 unless there is no other route |
| Risk prevention plans (PPR) | Plans for flood, forest fire and ground movement mark zones where building is prohibited or restricted |
| Brush clearance (OLD) | In or within 200 metres of woods, garrigue or maquis: clear 50 metres around the house outside urban zones, even beyond your boundary; the whole plot in urban zones; 100 metres in some zones covered by a forest fire plan |
Since 1 January 2025 the brush-clearance duty must be stated in property adverts and in the risk report. The seller also attaches a sworn statement of compliance to the sale contract. Our diagnostics guide explains the risk report.
Buying a house with a pool or an extension
- Ask the seller for the permis or DP for each pool, extension, veranda and outbuilding, with proof of display on site.
- Ask for the completion declaration and, ideally, the certificate of non-contestation.
- Compare the floor area in the advert with the area in the permits and in the tax records.
- Check the plot's zone in the PLU and any risk plan before relying on future works.
- Ask your notaire to review the planning history before the compromis.
Criminal action over unauthorised works is possible for six years after completion; the commune can bring a civil action for ten. Once a building has been complete for more than ten years, a new application cannot be refused because of the original irregularity, but this protection does not apply to work built without any required permit or in a risk plan's danger zone. Our guide on how to buy property in France sets out when these checks fit into the purchase.
Frequently asked questions
Do I need permission to build a pool in France?
Usually yes. A basin over 10 m² needs at least a déclaration préalable. Over 100 m² or with a cover of 1.80 m or more, it needs a permis de construire. Even a smaller pool needs a déclaration in a protected area.
How long does planning permission take?
One month for a déclaration préalable and two months for a permis de construire for a house, from the date the file is complete, with an extra month in protected areas.
When do I need an architect?
When the total floor area of the house after the works exceeds 150 m².
Can I fill my pool during a drought?
Not when your commune is at crisis level, when filling or topping up a private pool is banned. Restrictions also apply at alert level. The situation changes week by week, so check VigiEau.
What happens if the previous owner built a pool without permission?
The risk stays with the property. The commune can act for ten years after completion. A pool built without any required permit never gains the protection of the ten-year rule. Ask for the permits before you sign.
Is pool safety equipment compulsory?
Yes, for every private in-ground pool that is not enclosed. One of four standard devices is required: a barrier, an alarm, a cover or an enclosure.
Last updated: 11 October 2026