When purchasing a property or organising building work, the question of shared walls is crucial. A wall separating two properties can be either shared (belonging to both neighbouring owners) or private (belonging to only one).
The land registry is often the first source of information consulted by owners. But how can you tell if a wall is shared by reading a cadastral map? This guide explains the steps to follow, the clues to look for, and the additional steps to take to confirm the legal status of your dividing wall.
Consult the cadastral map: the first step
The cadastral map is a graphic document that shows the boundaries of properties and buildings on the ground. It is an excellent source of information about the nature of a wall, even though its main purpose is fiscal.
Accessing and reading the online land registry
To begin with, you need to consult your local council’s map. The easiest way to do this is to visit the official website cadastre.gouv.fr.
- Locate your plot and your neighbour’s plot on the map.
- Examine the dividing line that marks the boundary between the two properties.
Key information about the dividing line: A single or thick line that separates two plots exactly without any dashes on one side usually indicates a party wall or a shared property boundary.
- If the line is single, it marks the boundary. If it is confused with a wall, it is presumed to be a party wall.
- If the line is thicker (representing the wall itself) and straddles the boundary, this is a strong indication of a party wall.
What specific details should be read on a cadastral map for a party wall?
Cadastral maps may use different symbols to indicate the status of a wall or fence. Although the symbols used to indicate shared ownership are not always standardised, some signs are clear indicators:
- Absence of a unilateral black dash: This is the most commonly cited indicator. A small black dash (or hatch) attached to only one side of the dividing line traditionally indicates a private wall or fence belonging to the owner on the side of the dash. Its absence suggests joint ownership.
- Colours: Buildings are often shown in yellow or orange. If the wall is coloured and appears to straddle both plots equally, this may also indicate joint ownership.
- Annotations: Sometimes explicit annotations (M for joint ownership) are present, but this is rare on modern online plans.
Reminder: The cadastral map is a tax document, not a title deed. Although it provides strong evidence, it does not constitute absolute legal proof of joint ownership.
Additional clues to confirm the status of the wall
Given the indicative nature of the land registry, it is essential to cross-check the information with other sources.
Verification of joint ownership in the title deed
The most reliable source of information regarding the legal status of a wall is your notarised title deed and that of your neighbour, if you are able to consult it.
- Clauses and easements: Title deeds must clearly state the status of dividing walls at the time of sale, particularly if there is an agreement to waive joint ownership or an easement.
- Previous title deeds: Sometimes, the status is recorded in the previous title deeds.
The absence of a clear mention in the deed regarding whether the wall is private or shared does not contradict the legal presumption, but an explicit mention is prima facie written evidence.
Physical marks on the wall
The Civil Code, particularly Article 660 et seq., details physical marks that are presumptions of non-joint ownership, i.e. that indicate that the wall is private. The absence of these marks reinforces the presumption of joint ownership.
You should look for certain features on the wall separating the properties:
- Sloping coping: If the top of the wall is sloped to allow rainwater to run off on one side, the wall is presumed to be private and belongs to the owner towards whom the water runs.
- Unilateral construction elements: The presence of corbels, nets or overflow tiles positioned and constructed for a single owner is a physical sign indicating a private wall.
- The slope of the top: A unilateral slope at the top often indicates a construction exclusive to one of the properties.
If none of these marks are visible, the law tends to apply the presumption of joint ownership.
Presumption of joint ownership and civil law
Article 653 of the Civil Code: the principle of presumption
In French civil law, there is a fundamental rule:
Civil Code, Art. 653: “In towns and the countryside, any wall serving as a separation between buildings up to the roof, or between courtyards and gardens, and even between enclosures in fields, is presumed to be shared, unless there is evidence to the contrary.”
This means that if you have no written proof or physical mark proving that the wall is private, the law presumes it to be shared. This legal presumption is very strong and simplifies the management of conflicts between neighbours.
Differences between presumption of joint ownership and written proof
- Written evidence (title): This refers to the information mentioned in title deeds or a private deed. It is the most solid evidence that overturns any presumption.
- Presumption: This is the assumption that the wall is a party wall until evidence to the contrary is provided (a mark or title).
Important: Even if the land registry indicates a common boundary, the presumption only applies to walls that actually serve as a separation.
In case of doubt or conflict: How should you respond?
The land registry may contain errors (it is estimated that around 15% of plans contain inaccuracies regarding boundaries), especially if it is old. If your neighbour disputes the shared ownership or if the evidence is contradictory, you should seek professional assistance.
When should you call in a chartered surveyor and how much does it cost?
A chartered surveyor is the only professional authorised to officially define property boundaries on the ground by means of a boundary demarcation operation.
- Their role: They carry out a precise survey of the land, check old titles and plans, and can provide you with an official document on the status of the wall.
- The cost: The cost varies depending on the complexity of the land and the region. For an amicable boundary survey and a report on the boundary, the price can range from €1,500 to €3,000 or more. This cost is shared if the neighbour agrees to the amicable boundary survey.
Other professionals to consult
- Notary: For analysis of all title deeds and existing easements.
- Bailiff: For an official report on the condition of the wall and physical signs of non-joint ownership. This report can be used as evidence in court proceedings.
- Lawyers specialising in property law: If a persistent legal dispute over rights to the wall needs to be brought before a court.
The implications of joint ownership
Determining the status is vital, as joint ownership has major implications in terms of rights and obligations:
- Maintenance and repairs: Maintenance and repairs to the party wall (except in cases of deliberate damage) are the joint responsibility of both owners.
- Construction: Each owner has the right to build structures against the wall or insert beams into it, provided that this does not cause damage to the other owner.
Knowledge is the first step towards getting on well with your neighbours and managing your property in the best possible way.
In short
To find out if your wall is a party wall, start by consulting the online cadastral map, then confirm the status using your title deed and by observing physical marks. In the absence of written proof or marks to the contrary, the presumption of the Civil Code applies, and the wall is presumed to be a party wall.
