Does the cadastre prove ownership and a plot’s boundaries?
No. The cadastre is a tax document: it is used to compute local taxes, does not fix property boundaries and does not prove who owns the land. Ownership is proved by the title, normally the notarial deed published at the land registry (service de la publicité foncière). Boundaries are fixed by a boundary survey (bornage), which any owner can require of their neighbour (art. 646 of the Civil Code) and which a géomètre-expert, a chartered land surveyor, carries out.
A tax document
The cadastre records properties so that the property tax and other local taxes can be assessed. The map draws the parcels from old surveys or successive updates, with an accuracy that varies from commune to commune. The cadastral area is an indicative figure. Service-public says so explicitly: the cadastral map does not fix property boundaries, and owners' names do not appear on it.
For a specific address, the free ScanAdresse preview shows what the registers say.
What proves ownership
Ownership is proved by the title: the deed of sale, gift or partition, received by a notary and published at the land registry, which makes the transfer enforceable against third parties. The registry provides information on successive owners, prices, mortgages and the easements written into the deeds, and normally replies within 10 days. In the Bas-Rhin, Haut-Rhin and Moselle départements, the livre foncier plays this role.
Long-standing possession can also lead to ownership: in principle after 30 years, or 10 years with a valid title and in good faith (art. 2272 of the Civil Code). This is one reason why a fence or a long-established use may not match the map. If in doubt, the notary or a lawyer will assess the situation.
What fixes boundaries: the bornage
A bornage defines the boundary between two neighbouring private properties and marks it with boundary stones. It is not automatic, but becomes compulsory as soon as one owner asks for it: the neighbour cannot refuse, and the costs are in principle shared (art. 646 of the Civil Code). It is first done amicably: a géomètre-expert examines the titles, draws up a boundary report with a plan and sets the stones. Once signed by both neighbours, the report fixes the boundary for good. If they disagree, an attempt at conciliation comes before a court-ordered bornage.
Bornage does not apply against public land, such as a road: the boundary is then fixed by an alignment procedure with the public authority.
What the buyer can check
- Ask whether a boundary report exists; it is often annexed to deeds of sale.
- Compare the advertised area, the cadastral area and, if there is one, the surveyor’s plan.
- Look at the fences, hedges and walls on site, and ask whether they are shared.
- Ask the notary for the easements written into the seller’s title.
If the boundaries matter for your project, a pool, an extension or a division, you may, as a prospective buyer, request a bornage, or have a related condition written into the compromis.
When doubt is costly
Boundaries become decisive when you want to build near a side boundary, divide the land or buy a building plot: the PLU distances are measured from the real boundary, not from the line on the cadastre. A plot on a housing estate, for its part, must be marked out by a bornage before the sale.
ScanAdresse shows the address’s cadastral parcel and the registers that relate to it; like the cadastre, it proves neither ownership nor boundaries; €29 including VAT, free preview.
Frequently asked questions
Can the cadastre be used as evidence in court?
It may be one clue among others, but it does not prove ownership on its own. The court relies first on the titles and, if needed, on a géomètre-expert’s opinion.
Who pays for the bornage?
When agreed amicably, the surveyor’s fees are usually shared between neighbours, unless they agree otherwise. In court, the judge decides how they are split.
Is the land area guaranteed on purchase?
For a house, no rule guarantees the land area the way the loi Carrez does for a co-ownership unit. A surveyor’s plan is the most reliable reference.
Sources
- Service-public: boundary surveys
- Service-public: consulting the cadastre
- Service-public: property information
- Civil Code, art. 646 and 2272
ScanAdresse is a private service by SRI Group BV (VAT BE1037052239), not connected to any public authority: it brings together public data, with the source and date of every item.
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