Planning Permission: When Unauthorised Works Cause Harm to Neighbours

Imagine: you live in Nancy, Rue Saint-Nicolas, in a peaceful townhouse. One morning, your neighbour starts works: a two-storey extension, without any permission. Construction vehicles block the street, dust invades your garden, and soon the new building blocks your light. You are furious, but can you actually obtain compensation? The answer is yes, since a fundamental judgment of the Court of Cassation of 17 January 1984.

This decision, often unknown to the general public, established a clear principle: the rules on planning permission protect not only the general interest (town planning, landscape) but also the individual interests of neighbours. In short, if unauthorised works cause you direct and personal harm, you can claim damages.

But beware, it is not that simple. The same decision specifies that the municipality cannot claim damages for the same harm as the residents. Why? Because its harm must be distinct. Let us break down this leading decision, its implications and practical advice to avoid finding yourself in such a situation.

The Facts: A Story That Happens Every Day

In this case, a property owner in Dombasle-sur-Meurthe had undertaken construction works without obtaining planning permission. His neighbours, exasperated by the nuisance (noise, dust, loss of sunlight), sued him for compensation. The municipality of Dombasle-sur-Meurthe also joined the action, claiming damages for the harm to its town planning.

The criminal court convicted the builder for breach of planning permission legislation. But the question was: can the neighbours and the municipality obtain damages? The Court of Appeal said yes for the neighbours, considering the nuisance intolerable, but also for the municipality, for a certain amount. The builder then appealed to the Court of Cassation.

The Court of Cassation upheld the compensation for the neighbours: the direct and personal harm was well established. However, it quashed the decision concerning the municipality, holding that the Court of Appeal had not shown harm distinct from that of the residents. The municipality could not simply claim that the infringement harmed its planning rules; it needed specific harm, such as financial loss or damage to its image.

The Reasoning of the Court — Explained

The Court of Cassation relies on a two-step reasoning. First, it recalls that the provisions of the Town Planning Code relating to planning permission were enacted in the general interest. This means that their primary objective is to protect public order, the environment and land use planning. But, adds the Court, these provisions also aim to protect individuals. Why? Because illegal works can cause direct and personal harm to neighbours, such as noise nuisance, loss of view or depreciation of property.

Next, the Court upholds the compensation for the neighbours on the ground that the works carried out without permission caused them intolerable nuisance. The term 'intolerable' is important: a mere inconvenience is not enough; there must be an abnormal disturbance exceeding the ordinary inconveniences of neighbourhood. For example, temporary disruption due to renovation works would not suffice; however, a massive construction that blocks light and view for months, yes.

This decision confirms earlier case law. It does not create a new right, but clarifies the legal basis: civil liability under Article 1240 of the Civil Code (former Article 1382) applies, even in town planning matters. The builder committed a fault (building without permission), which causes damage (nuisance), and he must repair it.

What This Means for You — Practically

If you are a property owner in Nancy or elsewhere, and you plan works, know that the absence of planning permission not only exposes you to criminal prosecution (fine, demolition) but also to damages to your neighbours. Illustrative example: a client in Dombasle-sur-Meurthe had to pay €8,000 to his neighbours for loss of sunlight and €5,000 for noise nuisance, plus a fine of €20,000. That is a total of €33,000.

If you are a tenant, you can also act if your neighbour's unauthorised works cause you harm (noise, insalubrity). But be careful, your harm must be direct and personal: you cannot act on behalf of the co-ownership.

If you are a buyer, always check that existing constructions were built with planning permission. A seller who built without permission can be ordered to compensate you if you discover the problem after the sale. Limitation period: the civil liability claim is barred after 5 years from the discovery of the damage, but note that the criminal action for breach of planning permission is barred after 6 years from the completion of the works.

Four Tips to Avoid This Type of Dispute

• Before building, always check whether planning permission is required. Do not rely on a neighbour or a tradesman: consult the town planning department of your town hall. In Nancy, for example, any construction with a footprint of more than 20 m² requires permission.
• If you are a neighbour, document the nuisance. Take photos, videos, note the dates and times of noise, measure the loss of sunlight. All this will serve as evidence if you bring an action.
• Do not wait until the works are completed to act. You can apply to the interim relief judge for a suspension of the works pending the judgment on the merits. This can prevent irreversible harm.
• In case of dispute, consult a solicitor specialising in property law. The rules on limitation and evidence are technical. A simple report from the municipal police is not always enough; you must prove the causal link between the lack of permission and your harm.

Further Reading: Related Case Law and Developments

This 1984 decision has been confirmed several times. For example, in a judgment of 12 July 1995 (No. 93-17.006), the Court of Cassation granted damages to neighbours for loss of view caused by an unauthorised construction. More recently, the Court recalled that the harm must be assessed as at the date of the judgment and not at the date of the works (Civ. 3e, 10 March 2016, No. 15-10.042).

The trend is therefore towards increased protection of neighbours. Courts are increasingly sensitive to environmental nuisance and loss of property value. However, if you are the builder, you can try to show that the permission would have been granted anyway (for example, if your project complies with the Local Town Planning Plan). But this is a difficult defence, as the lack of permission is in itself a fault.

In Practice: What to Do

Quick FAQ:

• Can I obtain the demolition of an unauthorised construction? Yes, if you show serious harm. The judge can order demolition under a penalty (e.g., €100 per day of delay).
• What are the time limits to act? The civil claim is barred after 5 years from the discovery of the damage; the criminal claim after 6 years from the completion of the works.
• What if the town hall refuses to take action? You can act directly in court, without waiting for the town hall. Planning permission is also a protection for you.
• Can I be compensated for the loss of value of my property? Yes, if you obtain a property valuation quantifying the diminution (e.g., a 15% loss in market value).
• Are damages capped? No, they are proportionate to the harm. But expect modest amounts for temporary nuisance (a few thousand euros) and higher amounts for permanent losses.

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 →