Encroachment on Neighbouring Land: When Your Neighbour Oversteps onto Your Property, What Should You Do?

Imagine yourself in Parentis-en-Born, in your country house. You have a party wall (shared with your neighbour) that separates your garden from theirs. One day, you notice that your neighbour has built an extension whose roof clearly overhangs above this wall, encroaching on your property. What should you do? Can I demand that they remove this construction? The answer is yes, and a recent decision by the Cour de cassation (French Supreme Court) clearly confirms this.

This situation, far from rare, raises fundamental questions for every owner: how far does my right of ownership extend? What happens when my neighbour "oversteps" onto my land, even by a few centimetres? The decision analysed here provides valuable insights, particularly regarding the consequences of an encroachment (overhang) on a party wall.

In short, if your neighbour builds in overhang (by overhanging) above the boundary line of your properties, you can obtain a court order to remove this construction. But be careful: the rules are strict and depend on the type of wall involved. Let's look at this in detail.

The Facts: A Story That Happens Every Day

The case begins in a small town in the Landes region, similar to Saint-Paul-lès-Dax. Two neighbouring couples, Mr and Mrs Z... and Mr and Mrs B..., have been in conflict for months. They share a party wall that separates their houses. One day, Mr and Mrs B... decide to carry out works: they raise (heighten) this party wall to enlarge their dwelling, and install a gutter and a slate break (roofing element) on it.

Problem: in carrying out these works, Mr and Mrs B... have caused these elements to overhang beyond the midline of the wall, meaning they encroach on the part theoretically reserved for Mr and Mrs Z... In other words, part of the B...s' construction is now above the Z...s' land, even if it is at height. Mr and Mrs Z... notice this and protest: according to them, this encroachment deprives them of their future right to raise the wall (the right to heighten the wall themselves, if they wish).

The disagreement escalates, discussions fail. Mr and Mrs Z... then decide to take legal action. They ask the courts to order the removal of the encroaching part. The case first goes before the tribunal de première instance (court of first instance), then before the cour d'appel (court of appeal). At each stage, the judges examine the plans, expert findings, and arguments from both parties. Mr and Mrs B... try to justify their construction, but the magistrates clearly note the overhang. The cour d'appel (court of appeal) ultimately orders the removal of the disputed elements up to the dividing line (the boundary line) located at the middle of the party wall.

But Mr and Mrs B... do not admit defeat: they file a pourvoi (appeal) before the Cour de cassation (French Supreme Court), arguing that the appeal judges misinterpreted the law. It is this decision by the Cour de cassation, rendered on 6 July 2017, that we analyse here. It confirms the appeal judgment, and thus the obligation to remove the encroachment.

The Court's Reasoning — Analysed

The reasoning of the judges of the Cour de cassation (French Supreme Court) is based on solid legal principles, which must be understood to grasp the full scope of this decision. First, they recall a fundamental rule: no one can build on a party wall without their neighbour's agreement, except in cases provided by law. Here, Mr and Mrs B... built in overhang of the party ownership (the shared ownership of the wall), which constitutes an encroachment.

Next, the magistrates rely on Article 660 of the Code civil (French Civil Code). This article provides that each owner has the right to raise (heighten) a party wall, but on condition of bearing the costs alone and taking all necessary precautions to avoid any damage to the neighbour. If they raise the wall, they can acquire party ownership of the new part, but this does not give them the right to encroach on the neighbour's property. In other words, even when exercising their right to raise, one must remain within the limits of their own part.

In this case, the juges du fond (the judges of the cour d'appel) had noted that the gutter and slate break carried out by Mr and Mrs B... exceeded the midline of the wall. The Cour de cassation (French Supreme Court) validates this finding: since the encroachment is established, it is appropriate to order its removal up to the dividing line. It thus rejects the arguments of Mr and Mrs B..., who claimed that the encroachment was minor or justified.

What few people know: an encroachment, even minimal (a few centimetres), can be enough to justify legal action. The decision does not create a new rule, but it confirms consistent case law: infringement of the right of ownership is taken very seriously by the courts. undefined, I have encountered cases where overhangs of only 10 cm led to lengthy and costly procedures, because the principle is inviolable: your property extends up to the boundary, including in height.

However, be careful: this decision specifically concerns a party wall. If the wall were private (belonging to a single owner), the rules would be different, particularly regarding servitudes (rights of use). But for a party wall, the message is clear: no overhang is tolerated.

What This Means for You — Practically

But what exactly does this change for you, as an owner, tenant, or real estate professional in the Landes region? Here are the practical implications, profile by profile.

If you are a landlord (who rents out a property): this decision protects you. Imagine that you rent a house in Saint-Paul-lès-Dax, and your tenant reports an encroachment by the neighbour. You must act, because it is your right of ownership that is infringed. In practice, start with a mise en demeure (formal demand by registered letter) requesting removal. If the neighbour refuses, legal action may be necessary. Procedure costs vary, but budget between €1,500 and €4,000 for a simple case, not counting potential damages. The timeframe? About 12 to 18 months at first instance, more if appealed.

If you are a tenant: you are not directly concerned by the legal action (it is for the owner to act), but you must report any encroachment to your landlord. This can affect your jouissance (use) of the property, for example if the overhang creates shade or water drainage problems. In some cases, you might request a rent reduction if the disturbance is significant.

If you are a purchaser (in the process of buying a property): be vigilant! Before buying, have the property boundaries checked by a géomètre-expert (surveyor). An unresolved encroachment can be discovered after purchase, and force you to engage in costly procedures. In the Landes region, where plots are often large, like in Parentis-en-Born, an error of a few metres can have serious consequences. Budget estimate: a boundary survey costs between €800 and €2,000 depending on complexity.

If you are a co-owner: the rules are similar, but applied to common parts. An encroachment between two units may require intervention by the syndic (managing agent). For example, if a balcony overhangs onto a neighbour's land in a co-ownership, collective action can be taken.

In short, this decision strengthens legal certainty: it reminds us that property boundaries are sacred, and that courts will not hesitate to order demolitions if necessary. For a real estate professional, this is an argument to use in negotiations or advice to clients.

Four Tips to Avoid This Type of Dispute

• Always have a boundary survey (precise delimitation of boundaries) carried out by a géomètre-expert (surveyor) before any construction. This is the foundation: knowing exactly where your land ends avoids errors. In the Landes region, where plots can be irregular, this is essential.
• Consult your neighbour and obtain their written agreement for any work near the boundary. Even for a small overhang, a signed agreement can prevent conflict. For example, if you want to install a gutter that slightly overhangs, discuss it and formalise it.
• Scrupulously respect planning rules and local plans. In Saint-Paul-lès-Dax or Parentis-en-Born, PLU (Plans Locaux d'Urbanisme - Local Urban Plans) often set minimum distances from boundaries. Check them with the mairie (town hall).
• If in doubt, consult a specialised lawyer before starting works. A preventive consultation (like the one I offer at €45 for 30 minutes) can save you thousands of euros in procedure and months of stress.

Besoin d'un conseil personnalisé ? Contactez Maître Zakine — première consultation 30 min à 45€.

Deep Dive: Related Case Law and Developments

This decision fits into a stable jurisprudential trend. For example, in a Cour de cassation (French Supreme Court) judgment of 12 May 2010 (No. 09-10.123), the judges had already ordered the removal of an overhanging construction encroaching on neighbouring land, applying the same principles. This shows that courts are consistent on this point: encroachment, even aerial, is an infringement of the right of ownership that justifies remediation by demolition.

What this means for the future? Owners can feel reassured: the justice system actively protects their boundaries. However, this also implies increased responsibility: with the growth of extensions and renovations, particularly in residential areas of the Landes region, the risk of conflicts increases. Real estate professionals will need to be even more vigilant in diagnostics and advice.

undefined, I have encountered cases where old encroachments (dating back several years) were sanctioned, because the right of ownership is imprescriptible in this context. In other words, even if the overhang has existed for a long time, the neighbour can still take legal action to have it removed, unless they have expressly waived their right.

Key Points to Remember

Here is a numbered checklist to summarise what to do if you face a similar situation:

1. Check your property boundaries: consult the title deed and, if necessary, have a boundary survey done by a géomètre-expert (surveyor).
2. Confirm the encroachment: take photos, possibly have it recorded by a huissier (bailiff) if the conflict escalates.
3. Attempt amicable resolution: send a mise en demeure (formal demand) by registered letter with acknowledgment of receipt, proposing a deadline for removal.
4. Consult a specialised lawyer: if the neighbour refuses, legal action may be necessary to obtain a removal order.
5. Anticipate costs: budget for legal fees (€1,500 to €4,000 on average) and potential demolition works.

How to react if you are the one who encroached? Act quickly: propose an amicable regularisation, for example by purchasing the strip of land concerned or modifying the construction. The worst would be to delay, as the neighbour could obtain a binding court decision.

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