Property Boundary Survey Before Buying — Why It’s Essential

Checking property boundaries before you buy: why it’s decisive

Before any property purchase in the Alpes-Maritimes or the Var, verifying the size and boundaries of the plot protects you from unpleasant surprises: a wall encroaching onto the property, a swimming pool partly located on the neighbour’s land, an undisclosed right of way, or an actual surface area smaller than stated in the preliminary agreement.

Key points to check before signing

• Discrepancy between the land registry and the title deed: in the event of a mismatch, the title deed takes precedence; a documentary check is essential
• Existing fences and walls: do they follow the legal boundary or simply mark de facto occupation?
• Neighbouring structures: sheds, terraces, hedges — anything straddling the boundary line is a potential source of dispute
• Apparent easements: rights of way, pipework, cables — visible on site but not always mentioned in the deed

The pre-purchase survey

We carry out either a contradictory boundary survey (bornage) or a simple topographic check (GNSS survey) compared against the land registry and title deeds: you sign with full knowledge of the facts, or you renegotiate. The cost of a check (starting from a few hundred euros) is nothing compared to the cost of an encroachment dispute.

Preliminary sale agreement: clauses worth adding

If there is any doubt about the boundaries at the time of the preliminary sale agreement, it is possible to include a condition precedent tied to carrying out a boundary survey or topographic check before the final deed is signed. This precaution, still too rarely used, protects the buyer without blocking the transaction: it simply provides extra time to clear up any doubt before the deed is finalised.

What does overlaying the land registry with an aerial photo reveal?

Cross-referencing the cadastral plan with a recent aerial photo (IGN orthophoto) often makes it possible to spot, within a few minutes, significant discrepancies between the actual occupation of the land (fences, pools, outbuildings) and the theoretical boundaries — a quick, low-cost first level of analysis before commissioning, if necessary, a more thorough on-site survey.

The notary’s role in these matters

The notary checks the legal validity of the deed but does not carry out a physical check of the boundaries on site: this is an essential distinction to understand. The legal security of the deed is not the same as the technical certainty of where buildings actually sit — which is why it’s worth bringing in a land-use surveyor as well, particularly for properties with a pool, outbuildings, or sloping land.

FAQ

Does a pre-purchase check delay the transaction? A simple documentary check and site visit can be carried out within a few days; only a full contradictory boundary survey, if it turns out to be necessary, takes longer.

What can be done if a discrepancy is found after signing? Recourse remains possible under the hidden defects warranty or for non-conformity, but it is always preferable — and less costly — to act before signing.

Also read: Land registry errors and encroachment · Boundary survey guide for the 06 and 83 départements

The hidden defects warranty: the key legal text

If the boundary check reveals a defect that makes the property unfit for its intended use, the buyer has the benefit of the statutory hidden defects warranty:

« The seller is bound by a warranty on account of the hidden defects of the thing sold which render it unfit for the use for which it was intended, or which so impair that use that the buyer would not have acquired it, or would have paid a lower price for it, had he known of them. »
— Article 1641, French Civil Code

The buyer can choose either the redhibitory action (returning the property in exchange for a refund of the price) or the estimatory action (keeping the property with a partial refund), as provided for in Article 1644. Be careful of the time limit: Article 1648 requires action to be brought within two years of discovering the defect — which is precisely why a pre-purchase survey, or a swift inspection right after signing, is so valuable.

Legal sources

• French Civil Code — Legifrance
• Property purchases and sales — Service-public

📅 Last updated 18/08/2026 — By Cassini Expertise, independent building surveyor covering the Alpes-Maritimes and Var (06 & 83). Free quote: 04 22 46 06 04.

Frequently asked questions

How do you determine your property boundaries before buying?

To determine a property’s boundaries before buying, you need to bring in a licensed land surveyor (géomètre-expert) to carry out a boundary survey. This professional establishes the exact limits of the plot based on the title deeds and land registry documents. The survey is contradictory, meaning the neighbour must be given notice to attend, and the resulting official report is then registered with the land registry office.

Why have a boundary survey done before buying land?

A pre-purchase boundary survey is essential to avoid disputes with neighbours and to make sure the land matches exactly what is being sold. It establishes the precise boundaries and actual surface area, and confirms that any existing buildings comply with legally required setback distances. This protects the buyer against surface area errors or encroachments and secures the transaction.

Who pays for the boundary survey when buying a property?

The cost of a boundary survey is generally borne by the buyer if requested for their own information, although it can be negotiated with the seller. In the context of a sale, if the survey is included in the preliminary sale agreement, the parties can agree to split the cost. Failing an agreement, whoever requests the survey pays for it, but it is common for the buyer to cover the cost in order to secure their purchase.

📅 Mis à jour le 25/09/2026 — Cassini Expertise, expert bâtiment indépendant (06·83·13·40).