Definitive Boundary Determination: Can I Still Claim Ownership of a Plot?

Imagine: you have just bought a house in Rambouillet. Your neighbour has installed a fence which, in your opinion, encroaches on your land. You consult the boundary determination (the deed that delimits the properties) carried out by a surveyor and approved by a judgment of 1999. You think you are entitled to demand the demolition of this fence. But your neighbour retorts: "The boundary determination is definitive, you can no longer contest anything." Is he right? Not necessarily. The Court of Cassation, in a decision of 10 November 2009 (No. 08-19.756), provides a crucial clarification: a definitive boundary determination does not bar an action for recovery of ownership (an action by which one asks the court to recognise one's right of ownership over property). In other words, even if the dividing line has been fixed, you can still prove that you are the owner of the disputed plot. Analysis.

The facts: a story that happens every day

The case opposes Mrs X to Mr Y, two owners of adjoining plots in Houilles. In 1999, a judgment orders the boundary determination of their lands. But Mr Y opposes the placement of the boundary markers. Despite this, the surveyor draws up a boundary plan, and the court approves this plan in 2000, thus fixing the dividing line (the limit between the two properties).

Years later, Mrs X notes that Mr Y has erected a fence that does not respect this line. She sues Mr Y for demolition of the fence and for recovery of the encroached plot. Mr Y counterclaims for recognition of his ownership of that plot.

The Court of Appeal (second instance court) rules in favour of Mrs X: it orders the demolition of the fence and dismisses Mr Y's claim, on the ground that his action for recovery of ownership seeks to challenge a definitive boundary determination, which would be inadmissible. Mr Y appeals to the Court of Cassation.

The high court quashes the Court of Appeal's decision. Why? Because the 2000 boundary judgment merely fixed the dividing line, without deciding the question of ownership of the disputed plot. Yet Mr Y's action for recovery of ownership specifically concerned ownership. The definitive boundary determination therefore did not bar this action. The Court of Appeal had violated Article 1351 of the Civil Code (relating to the authority of res judicata, i.e. the principle that a final court decision cannot be challenged in new proceedings between the same parties and concerning the same subject matter).

The reasoning of the court — explained

The Court of Cassation relies on Article 1351 of the Civil Code (now codified as Article 1355). This article provides that "the authority of res judicata applies only to what has been the subject of the judgment. It is necessary that the thing claimed be the same; that the claim be based on the same cause; that the claim be between the same parties, and brought by and against them in the same capacity." In short, for a decision to prevent a new action, the three elements (object, cause, parties) must be identical.

Here, the object of the first judgment was the boundary determination, i.e. the fixing of the limit between the properties. The cause was the right of ownership of each party over their respective plot, but the judge did not have to determine who owned the disputed strip of land. In contrast, Mr Y's new action for recovery of ownership had as its object the recognition of his right of ownership over that strip. The object and cause were different. Therefore, the authority of res judicata could not be invoked to block the action for recovery of ownership.

The Court of Cassation does not create new law: it reminds of a fundamental principle. undefined that boundary determination and recovery of ownership are two distinct actions. Boundary determination does not prejudge ownership, unless the judge has expressly ruled on this point. However, beware: if the boundary judgment had also decided the question of ownership (for example, by stating "plot A belongs to Mr X"), then the action for recovery of ownership would be inadmissible.

What few people know is that boundary determination can be amicable or judicial. In both cases, the surveyor relies on title deeds (notarial deeds) and possession (occupation of the land). But if the titles are imprecise or contradictory, the judge may be led to interpret the parties' intention. undefined, I have encountered cases where an old boundary determination was carried out on the basis of erroneous cadastral plans, creating conflicts years later.

What this means for you — concretely

For the owner who suffers an encroachment: If your neighbour has built a fence or building that goes beyond the boundary line, you can demand demolition. But you must also be ready to prove that you are the owner of the encroached land. The boundary determination alone is not enough: you need a title deed or acts of possession (notarial deeds, attestations, etc.). Example: in Houilles, an owner whose garage encroaches by 2 m² on the neighbouring land may be forced to demolish it, even if the boundary determination is old, if the neighbour proves his ownership.

For the owner who is attacked: Do not hide behind a definitive boundary determination to refuse any discussion. You can always contest the ownership of your adversary. But beware: if you lose, you risk having to demolish and pay damages (Article 1240 of the Civil Code, which requires compensation for damage caused by one's fault).

For the buyer: Before buying a property, check whether a boundary determination has been carried out and whether it is disputed. If you buy land whose limit is uncertain, you could inherit a dispute. Ask for a guarantee of area clause (Article 46 of the Carrez law for condominium lots, or Article 1603 of the Civil Code for land sales).

For the co-owner: The rules are the same: a boundary determination between condominium lots (often carried out by a surveyor) does not definitively close the question of ownership of common or private parts. If a co-owner has encroached on a common part, the action for recovery of ownership remains open.

In figures: a boundary determination lawsuit costs on average €3,000 to €8,000 (surveyor fees and lawyer's fees). An action for recovery of ownership can double this amount. It is therefore better to attempt conciliation (Article 56 of the Code of Civil Procedure) before going to court.

Four tips to avoid this type of dispute

• Have an amicable boundary determination carried out as soon as possible: Upon acquisition of land, call on a chartered surveyor to fix the limits. This avoids nasty surprises. The cost (around €1,500) is an investment.
• Keep your title deeds carefully: The notarial deed, the cadastral plan, previous sale deeds. In case of dispute, these are your best weapons. Have them digitised and stored in a safe place.
• If in doubt about a fence, do not tacitly accept it: If your neighbour installs a fence that seems to encroach, express your opposition in writing (registered letter with acknowledgement of receipt). Silence can be interpreted as acceptance (peaceable possession).
• Consult a lawyer before taking legal action: A lawyer specialised in property law will analyse your chances and the strategy to adopt. Sometimes a simple formal notice is enough to make the neighbour back down.

Further reading: related case law and developments

The Court of Cassation has handed down several decisions to the same effect. For example, in a decision of 28 March 2018 (No. 17-14.783), it held that an action for recovery of ownership is not inadmissible after an amicable boundary determination, unless the parties intended to definitively settle the question of ownership. Similarly, a decision of 12 July 2018 (No. 17-21.680) specifies that a boundary determination does not constitute a title of ownership, but a mere record of the limit.

The trend of the courts is therefore to clearly distinguish between boundary determination (fixing the limit) and recovery of ownership (determination of ownership). This distinction protects owners who may have been prejudiced by an erroneous boundary determination. For the future, it is likely that judges will remain vigilant not to give boundary determination an extinctive effect that it does not have.

However, beware: if you attack too late, you may be faced with acquisitive prescription (Article 2272 of the Civil Code: 30 years for immovables). If your neighbour has occupied the plot for 30 years in a peaceable, public and unequivocal manner, he may become the owner. A recent boundary determination can therefore be useful to start a new limitation period running.

Summary and next steps

What to remember:

• A boundary judgment does not decide ownership, unless it does so expressly.
• An action for recovery of ownership is admissible even after a definitive boundary determination.
• Title deeds remain the essential proof.

What to do if your neighbour encroaches?

1. Check your title deed and the boundary plan.
2. Send a registered letter to your neighbour asking him to regularise the situation.
3. If no response, consult a lawyer to bring an action for recovery of ownership.
4. Do not forget prescription: act quickly.

Are you in a similar situation? A first 30-minute consultation with Maître Zakine (€45) can save you months of proceedings — and often much more. Book an appointment →