There are rules in France about what you can and cannot do to shared walls when you and your neighbour technically own one side each. We also explain the related responsibilities.
What is a shared or ‘party’ wall?
A shared wall or party wall, is defined as a single structure that separates your property from that of your next-door neighbour (owned by both parties). This could be a fence, a brick wall or even a hedge.
It can also be known as a ‘separating’ wall. It delineates your property boundary and may also play an important role in maintaining privacy and safety.
You and your neighbour share the wall. You own the side that faces your property and they own the other side that faces their property.
In France, the rules for shared walls are outlined in article 653 of the Civil Code (Code Civil). A shared garden wall is called a ‘mur mitoyen’ or a ‘mur séparatif’ in French.
How is a shared wall established?
Your title deed should outline whether your wall is shared or private. If your deed does not mention it, then article 653 steps in. A structure between two private properties is typically considered to be shared if it marks the boundary, for example:
Between two buildings
Between a courtyard and a garden
Between two fields
Can I do work on my side of a mur mitoyen?
You are legally allowed to undertake the following work on your side of the wall without needing permission from your neighbour:
Paint your side of your wall
Install plants on your side, provided they do not extend beyond the top of the wall
Rent out the face of the wall for advertising purposes, without having to share the fee.
Raise the height of the wall. This is known as exhaussement. The neighbour who wants to increase the wall height must pay the entire cost, and also any future maintenance costs due to the extra height. If the wall’s condition will not support the work, the neighbour doing the work must have it rebuilt or made structurally sound at their own expense before raising the height.
You must gain permission of the other co-owner to:
Fix support structures, including with beams or joists, into the wall beyond a depth of 54mm on your side.
Drill the wall for any reason.
Create openings, doors or windows.
What obligations and responsibilities do co-owners share?
Each co-owner of a shared wall must contribute jointly to the costs of maintaining, repairing, or rebuilding it. Excepting emergencies, work may only be undertaken with the agreement of the neighbouring co-owners.
Article 655 of the Civil Code states a ‘principle of proportionality’. This means that the co-owners must share the costs of repairing and maintaining a party wall in equal shares, unless their title deeds specifically state different proportions of ownership.
If one of the neighbours pays for joint work, the other neighbour must refund them their share.
However, if the work to the wall is required solely due to the actions of one of the neighbours - for example repairs to a damaged section - that neighbour alone must pay.
If one of the neighbours wishes to replace the wall, they can only claim money from the other neighbour if the work is structurally required to avoid the wall from falling down.
But if the work is purely cosmetic - for example, replacing a brick wall with stone - and the work is not necessary from a structural point of view, the neighbour replacing the wall must pay for the work in its entirety.
What if a co-owner does work without gaining the correct consent from the co-owner neighbour?
The unhappy party can take the other neighbour to court (tribunal judiciaire). The court can order the demolition of work which has already begun, and order any work to stop. It can also order the rebuilding of the wall to its original state.
If the work has caused damage to the plaintiff’s property, the court may order the payment of damages.
You can also speak to your local mairie if you suspect that your neighbour’s work does not conform to the Code de l'Urbanisme, and/or they have not obtained proper planning permission for the work. The Mairie can step in to stop work of this kind, and even order its demolition if needed.
Contravening the Code de l'Urbanisme can lead to a fine of €1,200 rising to as much as €6,000 per square metre of work, and even as much as €30,000, depending on the work done and the scale of the breach of planning permission. Repeat offenders can be given a jail sentence.
Can I build a wall or build against the wall on my side of the property, against the existing wall?
Yes, any co-owner may build against a shared wall and have beams or joists placed in it to within 54mm (article 657 of the Civil Code).
However, the work must not encroach onto the neighbour’s property or cause problems such as blocking out their light source. In which case the neighbour can legally ask for the wall to be demolished or lowered.
Can I build a separating wall or divider if one does not yet exist?
Yes, under certain conditions, as stated by Article 663:
If your property is located in a commune with a population of less than 50,000, the wall must be at least 2.60 metres high
If your property is located in a town with a population of 50,000 or more, your wall must be at least 3.20 metres high
The two neighbouring owners must draw up a party wall agreement (‘une convention de mitoyenneté’) with a notaire. As the wall will be more than two metres high, you must also submit a prior declaration to the Mairie (under Article R421-9 of the Code de l'Urbanisme).
Can I claim full ownership of the wall?
Full ownership can happen by default if only one neighbour maintains the wall without any protest from the other neighbour over a period of 30 years, as stated by article 2272 of the Civil Code. After 30 years the neighbour who has maintained the wall can technically claim ownership.
However, if there is any protest or conflict, the title deeds or contract will step in.
A co-owner can relinquish their ownership of the wall if it does not support their home or another building. They can officially relinquish ownership of the wall by drawing up an agreement with a notaire.
A co-owner can also purchase full ownership of the wall with the agreement of the neighbour. The purchase fee is 50% of the cost of the wall and the value of the land on which the wall is built, as stated by Article 661 of the Civil Code. The purchase must be via deed, drawn up by a notaire.