Encroachment on Neighbouring Land: Even Minimal, Demolition Is Required (Cass. 3e civ., 29 Feb. 1984)

Imagine: you have just bought a house with a garden in Châlons-en-Champagne. To enlarge your living room, you build an extension. The work progresses, everything seems perfect. Then, one day, your neighbour informs you, tape measure in hand, that your foundation encroaches 15 centimetres onto his plot. 'It's nothing,' you think. Yet, he demands the outright demolition of your extension. Is this legal? Can he really force you to tear everything down for so little?

The question every owner asks: can a minimal encroachment, made in good faith, escape demolition? The answer is no, and it is radical. This decision of the Court of Cassation of 29 February 1984 forcefully reminds us: no one may be compelled to give up their property, except for reasons of public utility. In other words, even an encroachment of a few centimetres, even unintentional, gives rise to the right to demolition of the encroaching structure.

But what exactly does this change for you, as an owner or neighbour? Let's decode this landmark decision together, its facts, its reasoning, and its practical consequences. I will also give you concrete advice to avoid finding yourself in such a situation, whether you are in Sedan, Reims, or elsewhere.

The Facts: A Story That Happens Every Day

Mr. X, an owner in Châlons-en-Champagne, decides to build a block of flats on his land. He entrusts the work to an architect. The work progresses, but a boundary or survey error causes the building to encroach onto the neighbouring property of Mr. Y. The encroachment is real, but its extent is minimal: a few tens of centimetres, probably. Moreover, the error was made in good faith: no one intended to steal land. Mr. Y, the neighbour, is not satisfied. He suffers a loss, admittedly slight, but he is the owner of that piece of land and intends to remain so. He sues Mr. X and the architect in court to obtain demolition of the encroaching part.

The judicial journey is classic. At first instance, the court recognises the encroachment but, considering its minimal nature and the builder's good faith, refuses to order demolition. It prefers to award damages to Mr. Y for his loss. Mr. Y appeals. The Court of Appeal confirms: no demolition, but compensation. Mr. Y, dissatisfied, appeals to the Court of Cassation. He invokes Article 545 of the Civil Code, which provides that 'no one may be compelled to give up their property, except for reasons of public utility'. According to him, leaving the encroachment in place, even in exchange for compensation, amounts to forcing him to give up his property, which is prohibited.

The Court of Cassation agrees with him. In its judgment of 29 February 1984, it quashes the decision of the lower courts. It affirms that Article 545 must be applied in all its rigour, even if the encroachment is minimal and even if it was made in good faith. The only possible exception is public utility, a concept not at issue here. In short, demolition is the rule, and the courts cannot replace it with damages.

The Reasoning of the Court — Analysed

The Court of Cassation relies on a fundamental principle: the right of property is absolute. Article 545 of the Civil Code is its expression: no one may be forced to sell or give up their property, except for a reason of general interest (expropriation). However, allowing a construction to encroach on another's land, even a tiny bit, deprives the owner of part of their property. It does not matter that the encroachment is minimal: property is not divided according to area. Every square centimetre belongs to the owner, and no one else may occupy it without their consent.

The Court clarifies that the good faith of the person causing the encroachment is irrelevant. In other words, even if you built without knowing you were on the neighbouring plot, you are not excused. The architect's or surveyor's error does not protect you. The aggrieved owner can demand restoration, i.e., demolition of the encroaching part.

What few people know is that the Court of Cassation could have adopted a more flexible position. Some lower courts, like those in the initial case, consider that compensation is sufficient when the loss is small. But the Court of Cassation puts an end to this temptation. It reminds us that the owner does not have to suffer an unlawful occupation of their property, even for money. The principle is binary: either you are on your property, or you are not. There is no 'almost on your property'.

Note, however, that the decision does not entirely close the door to an alternative solution. If public utility is at stake (e.g., a project of general interest), expropriation may take place. But in relations between individuals, no compromise. This position has been confirmed and reinforced subsequently, notably in a judgment of 31 March 2016 (No. 14-27.195) where the Court held that even an encroachment of a few centimetres onto a private road must be removed.

What This Changes for You — Concretely

For owners who build or have built: be extremely vigilant about the boundaries of your land. A boundary error, a misaligned wall, a balcony that protrudes 10 cm, and you risk demolition. The costs are your responsibility: demolition, reconstruction, architect's fees, not to mention potential damages for your neighbour's loss of enjoyment. In Sedan, for example, an individual had to demolish a garage encroaching 20 cm onto the neighbouring property, at a total cost of €15,000, while the value of the encroached land was negligible.

For neighbouring owners who suffer an encroachment: you have the right to demand demolition, even if the encroachment is minimal. Do not be swayed by arguments of good faith or insignificance. You may also, if you prefer, accept compensation (e.g., the value of the occupied land plus damages for loss of enjoyment), but that is your choice, not an obligation. If you accept compensation, remember to formalise the situation by notarial deed (sale of the plot or easement).

For tenants: you are not directly concerned, but if your dwelling encroaches on the neighbour, the owner (landlord) must bear the cost of demolition. You might have to endure works or even leave the premises temporarily. Check your lease: the landlord must rehouse you or reduce the rent during the works.

For buyers: before purchasing a property, have a boundary survey carried out by a chartered surveyor. Enquire about existing constructions: an extension or a party wall badly placed may hide an encroachment. You could inherit a dispute.

If you are in this situation, you must act quickly. The limitation period (time to bring an action) is 30 years for real property actions (Article 2227 of the Civil Code). But the longer you wait, the harder it will be to prove the encroachment (vegetation, alterations). Consult a solicitor specialising in property law as soon as you have any doubt.

Four Tips to Avoid This Type of Dispute

• Have your land surveyed before any construction project. A boundary survey officially delimits properties. It is carried out by a chartered surveyor. Its cost (€800 to €1,500) is negligible compared to the risk of demolition. A boundary survey carried out in the presence of neighbours is even safer.
• Require your architect or builder to provide an accurate setting-out plan. Do not settle for a rough site plan. Ask for a report of the cadastral boundaries and staking out on the ground before pouring foundations. Check the distances yourself against the boundary markers.
• If in doubt about a neighbouring construction, have the encroachment recorded by a bailiff. A bailiff's report is strong evidence. It describes the premises, measures distances, takes photos. This report can be made at any time, even before any dispute.
• Negotiate an amicable solution before going to court. If you discover an encroachment, discuss it with your neighbour. You can propose to buy the affected plot (sale of a strip of land) or create an easement (right to encroach). The agreement must be formalised by a notarial deed to be binding on future owners. The cost of a transaction is often much lower than that of a lawsuit.

Further Reading: Related Case Law and Developments

The 1984 decision has been consistently followed. For example, the Court of Cassation held on 31 March 2016 (No. 14-27.195) that even an encroachment of 7 cm onto a private road had to be removed, and the owner could not be compelled to accept compensation. In another judgment of 8 November 2017 (No. 16-22.593), it specified that demolition could be ordered even if the encroachment consisted of plantings (roots, branches) provided they caused a disturbance exceeding normal neighbourly obligations.

The trend is therefore very protective of property rights. Courts do not hesitate to order costly demolitions, even for minimal encroachments. This strictness aims to deter builders from taking liberties with property boundaries. In my practice, I have come across cases where a simple balcony protruding 15 cm had to be removed, at a cost of €8,000. Conversely, some lower courts sometimes try to soften the rule by invoking the disproportion between the cost of demolition and the harm suffered, but the Court of Cassation regularly calls them to order.

For the future, it is possible that case law may evolve towards greater flexibility in very specific cases (minimal encroachment, good faith, no harm), but for now, the rule remains inflexible. The only way out is an amicable agreement.

Key Points to Remember

• What to do if you are a victim of encroachment? Have the encroachment recorded by a bailiff, then serve a formal notice on the neighbour to demolish. If he refuses, sue him in court. You can claim demolition, damages, and legal costs.
• Can I keep the encroachment if I pay compensation to the neighbour? No, unless the neighbour agrees to sell you the land or grant you an easement. You cannot compel him.
• What are the risks if I do not demolish? The neighbour can obtain a court order for demolition under a penalty (e.g., €100 per day of delay). If you do not comply, the court may authorise the neighbour to have it demolished at your expense.
• Can I take action against my architect or builder? Yes, if the encroachment is due to their fault (error in plans, failure to respect boundaries). You can sue them for breach of contract to recover your loss (demolition costs, damages).
• Is there a time limit to act? Yes, the action for demolition is subject to a 30-year limitation period from the encroachment (real property action). After this period, you lose the right to sue.

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