Coastal erosion in France: 30- and 100-year zones

Which municipalities are concerned?

The list is set by decree, taking into account the vulnerability of the area to coastal retreat (code de l’environnement (Environment Code), art. L321-15). It is reviewed at least every 9 years and can be added to at any time at a municipality’s request.

Sources: GéoLittoral, page updated on 9 April 2026; decree no. 2026-95. A map of listed municipalities is published on GéoLittoral. Since 18 June 2026, the app “The coast of my municipality” (our translation) has brought together data on coastline change for more than 1,000 coastal municipalities (ministère de la Transition écologique).

This list is not the same as that of the municipalities subject to the loi Littoral (Coastal Act): see our guide acheter sous la loi Littoral (buying under the Coastal Act).

Zones exposed at 30 years and 100 years

A listed municipality that is not covered by a plan de prévention des risques littoraux (coastal risk prevention plan) dealing with coastal retreat must draw up a local exposure map (Planning Code, art. L121-22-1). The procedure for amending the PLU is started no later than one year after the list is published; if the PLU incorporating these zones has not come into force 3 years after that procedure was started, the municipality or the inter-municipal body adopts a provisional map before that deadline, applicable until the PLU comes into force, unless an approved coastal risk prevention plan already covers the area (art. L121-22-3).

In the 30-100 year zone, demolition is ordered by order of the mayor, with at least 6 months’ notice. For a project requiring a permit or a déclaration préalable (prior declaration), the estimated cost of demolition is deposited with the Caisse des dépôts (public deposit fund) before the works. Holders of rights over these buildings are not entitled to any compensation (art. L121-22-5).

Informing the buyer and the tenant

A property located in a zone exposed to coastal retreat, defined by a PLU, a carte communale (municipal land-use map) or a provisional map, requires a risk statement (Environment Code, art. L125-5; service-public.gouv.fr, checked on 28 September 2026). It is handed over at the first viewing and must state:

• the time horizon of exposure (30 years or 30 to 100 years);
• a reminder of the requirements applicable to the zone;
• the provisional nature of the zoning where it comes from a provisional map;
• whether the demolition and site restoration obligations apply to the property.

Every advertisement must carry the statement: “Information on the risks to which this property is exposed is available on the Géorisques website: www.georisques.gouv.fr”. If there is no risk statement, the buyer or tenant can apply for the contract to be rescinded or for a price reduction (art. L125-5).

A stricter rule applies in addition for the 30-100 year zone: any promesse de vente (preliminary sale contract), contract of sale or lease concerning a building subject to the demolition obligation must mention it, failing which it is void (Planning Code, art. L121-22-5, VII). See also our guide on the état des risques (ERP) (risk statement).

The right of pre-emption for adapting to coastal retreat

In listed municipalities, the municipality, or the inter-municipal body responsible for planning, has a specific right of pre-emption (Planning Code, art. L219-1):

• it applies automatically throughout the whole 30-year zone;
• it can be extended, by resolution, to all or part of the 30-100 year zone;
• in these zones, the droit de préemption urbain (urban pre-emption right) (art. L211-1) and that of zones d’aménagement différé (deferred development zones) (art. L212-2) do not apply.

In the 30-year zone, the price is set primarily by comparison with sales of properties at the same level of exposure; failing that, on the basis of properties outside the zone, with a discount reflecting the time remaining before the property disappears (art. L219-7). The general mechanism is explained in our guide on the droit de préemption (right of pre-emption).

Which professional to consult

The notaire (notary), who is notified of the pre-emption decision (art. L219-6), checks that the promesse mentions the demolition obligations. The géomètre-expert (chartered land surveyor) places the plot in relation to the boundaries of the 30-year and 100-year zones. The agent immobilier (estate agent) puts the Géorisques statement in the advertisement and hands over the risk statement at the first viewing. The diagnostiqueur (property surveyor) carries out the other surveys in the sale file.