Buying, building or extending a property by the sea in France means having to comply with the Coastal Law (loi Littoral), a protective piece of legislation that strictly regulates urban development in coastal municipalities. Since 1986, this law has limited new construction, requires continuity with already urbanised areas, and prohibits almost any project within the 100-metre strip from the shoreline. Understanding its main principles is essential before any coastal property project, whether it involves a purchase, new construction or an extension.
In summary
- The Coastal Law of 3 January 1986 strictly regulates urban development in coastal municipalities in order to protect natural areas and landscapes.
- Any new construction is, in principle, prohibited within the 100-metre strip from the shoreline, except in already urbanised areas.
- Urban expansion must take place in continuity with existing towns and villages, which greatly limits the possibilities for new construction or significant extensions.
- Before any purchase or building project, it is essential to check the precise zoning of the property in the local urban development plan (PLU) and to consult the municipality's planning department.
What is the Coastal Law? Origins and objectives
A founding law of 3 January 1986
The Coastal Law was adopted on 3 January 1986 in response to growing property pressure on the French coastline. Its objective is twofold: to protect the ecological and landscape balances of the coastline while organising sound development of these areas, balancing economic development, tourism and the preservation of natural spaces. It applies to municipalities bordering seas and oceans, but also to certain municipalities bordering major lakes and estuaries.
Codification within the Town Planning Code
The provisions of the Coastal Law are now incorporated into the Town Planning Code (Code de l'urbanisme), mainly in articles L121-1 and following. This codification did not alter the spirit of the original text: it merely clarified its legal structure, which makes it easier for local authorities and reviewing services to apply, but does nothing to ease the constraints placed on property owners and project developers.
The main principles of the Coastal Law
Continuity of urbanisation with existing towns and villages
The principle of continuity requires that any urban expansion take place in continuity with already established towns and villages, rather than as isolated constructions or piecemeal development scattered across the territory. In practical terms, a plot of land located outside already urbanised areas, even if it is buildable on paper, may be refused a building permit on the basis of this principle.
The prohibition on building within the 100-metre strip
Outside already urbanised areas, construction and installations are prohibited within a coastal strip of 100 metres measured from the high-water mark of the shoreline. This strip may even be widened by the local urban development plan (PLU) where grounds related to the sensitivity of the environment justify it. This rule explains why many plots of land close to the sea, though seemingly attractive, are in fact not buildable.
Protection of remarkable areas and areas close to the shoreline
Remarkable or characteristic coastal areas (dunes, cliffs, marshes, coastal forests, listed sites) benefit from enhanced protection that virtually excludes any new construction. In areas close to the shoreline, while not entirely prohibited, urbanisation must remain limited and must be justified and explained in the PLU, particularly according to the configuration of the site or the proximity of economic activities requiring access to water.
What are the practical consequences for property owners?
Building a new house in a coastal area
For a new construction project, the combination of the rules on continuity, the 100-metre strip and the protection of remarkable areas considerably reduces the number of plots that are actually buildable. A plot may be classified as buildable in the PLU while still being subject to restrictions arising directly from the Coastal Law, which takes precedence over local planning rules.
Extending or renovating an existing property
Owners of an already built house in a coastal area are not immune to strict constraints when considering an extension or enlargement. Depending on the exact location of the property (the 100-metre strip, area close to the shoreline, remarkable natural area), the possibilities for raising the roof, adding a veranda or extending on the ground can be very restricted, or even prohibited, even for a small-scale project.
The importance of checking the PLU before any project
Before starting work or submitting a building permit application, it is essential to consult the local urban development plan (PLU) of the municipality, which sets out the exact zoning of the property and the applicable rules. This check makes it possible to anticipate refusals of authorisation and to avoid projects doomed to administrative failure.
Exemptions and special cases provided for by law
Constructions related to public services and activities requiring proximity to water
The Loi Littoral (Coastal Law) provides for certain regulated exceptions. Constructions or installations necessary for public services or for economic activities requiring immediate proximity to water (port, shellfish farming or nautical activities, for example) may be authorised, subject to precise justification and suitable integration into the environment.
New hamlets integrated into the environment
Under certain conditions, the law allows for the creation of new hamlets integrated into the environment, outside the continuity of existing urban development. These operations remain rare, however, and are strictly regulated by local urban development documents, which must demonstrate their compatibility with the objectives of coastal preservation.
What impact on the value of already built properties?
Paradoxically, these strict constraints have a direct effect on the market: properties already built in a protected coastal area, particularly within the 100-metre strip or in immediate proximity to the shoreline, benefit from a scarcity that sustainably supports their value. The limitation of new supply prevents the construction of competing developments, which reinforces the attractiveness and value of existing properties. If you own a property by the sea, it may be worthwhile requesting a free property valuation to precisely measure this scarcity effect on your assets, and to compare your situation with our property listings in the same area.
Litigation and case law: a sensitive subject
Frequent annulments of building permits
The Loi Littoral is among the urban planning laws most frequently invoked before administrative courts. Many building permits issued in coastal areas are challenged by environmental protection associations, neighbours or local authorities, sometimes resulting in their annulment, even after work has begun.
Case law that continues to evolve
The criteria for applying the law (the notion of an urbanised area, the definition of a village or a built-up area, and the assessment of continuity) are the subject of abundant and evolving case law from the Conseil d'État and the administrative courts of appeal. This legal instability reinforces the need for a rigorous analysis before submitting any building permit application in a coastal area.
Our practical advice before buying or starting work
Before any purchase or extension project in a coastal area, several precautions are necessary. Always consult the PLU and the regulations of the municipality concerned to identify the exact zoning of the land or property. Contact the town hall's urban planning department to obtain a precise reading of the rules applicable to your plot, particularly if it is located within the 100-metre strip or in an area close to the shoreline. Also anticipate constraints before committing to an extension project, as a permit refusal could jeopardise the financial balance of the operation. To secure your project, the support of a local Capifrance property consultant allows you to benefit from sound knowledge of the market and the administrative specifics of your coastal area.
Conclusion
The Coastal Law (loi Littoral) constitutes a demanding but essential legal framework for preserving the lasting appeal of the French coastline. While it complicates certain building or extension projects, it also contributes to the scarcity and valorisation of properties already existing by the sea. Given the complexity and constant evolution of case law, each project deserves an individual analysis, drawing on the local urban planning department, a notary or a real estate professional well acquainted with these specific issues.
FAQ
Does the Coastal Law apply to all seaside municipalities?
It applies to municipalities bordering seas and oceans, as well as to certain municipalities bordering estuaries and large inland bodies of water designated by decree. Not all coastal municipalities are therefore affected in the same way, and the intensity of the constraints varies according to the precise location of the property. It is necessary to check on a case-by-case basis with the town hall.
Can an existing house be extended within the 100-metre strip?
This depends heavily on the exact classification of the land: in an already urbanised area, certain limited extensions may be authorised by the PLU (local urban plan), whereas outside these areas, the possibilities are very restricted or even non-existent. Each situation must be precisely verified with the urban planning department, as the rules vary from one municipality to another.
What is an area close to the shoreline within the meaning of the Coastal Law?
This is a zone wider than the 100-metre strip, defined according to criteria such as distance from the sea, mutual visibility or the nature of the surroundings. In these areas, development remains possible but must be limited, justified and explained in the local urban plan (PLU). Its exact perimeter is not fixed by a single distance and must be assessed locally.
How can I find out if my land is affected by the Coastal Law?
The best approach is to consult the municipality's PLU and to request a certificate of urban planning (certificat d'urbanisme) from the local urban planning department, which will specify the exact zoning and applicable rules. A notary can also provide guidance on these points during a purchase project. This verification is essential before any financial commitment.
Can a building permit granted in a coastal zone be cancelled afterwards?
Yes, permits issued in coastal zones are subject to numerous legal challenges, and some are cancelled by administrative courts even after work has begun, or even been completed. This is why it is recommended to legally secure your project in advance, drawing on a precise analysis of the applicable rules and, if necessary, the opinion of an urban planning law professional.
Do properties located in protected coastal zones gain more value?
Generally yes, because the scarcity of new supply linked to the constraints of the Coastal Law tends to reinforce the valorisation of properties already built in these sought-after areas. This effect is not automatic, however, and depends on many local factors, such as the condition of the property, its exposure or market dynamics. A precise valuation remains the best way to assess this potential.
Author
Frédéric Rémy – Director of Sales Performance
A real estate professional with several years of experience within the Capifrance network, I would like to share essential advice with you to help you successfully complete your property project with our advisors.
