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Published on 6 November 20266 min read
Party Wall in Belgium: Rules, Buy-Out and Sale
The Immolytics editorial team
A party wall is a wall that two neighbours share on the boundary between their plots. Under the Belgian Civil Code, a wall that separates two buildings is presumed shared, unless a deed or a visible sign says otherwise. Before a sale, you need to know who owns the wall, who maintains it and what the deed says.
What is a party wall in Belgium?
A party wall is a shared wall. It belongs to both neighbouring owners, half each, and it sits across the boundary between the two plots. A private wall is different. It belongs to one owner only, even when it is built right on the boundary line.
The difference matters in daily life. With a shared wall, neither neighbour can decide everything alone. Cutting a large opening, demolishing the wall or changing its structure also affects the other person's property. With a private wall, the owner has more freedom, but must still avoid harming the neighbour.
People often mix up a party wall and a terraced house. These words do not describe the same thing. A terraced house shares its side walls with the houses on both sides. A semi-detached house shares one wall with a single neighbour and is free on the other side. A detached house has no shared wall at all. These words describe the shape of the building. A party wall describes who owns the wall.
How do you know if a wall is a party wall?
To find out, look first at the titles, which means the property deed. Then look at the signs on site. If neither settles the question, the legal presumption applies. There is no single test. You compare several clues.
The property deed
Your purchase deed, or an older one, may say that the wall is shared, private or bought out. This is the first source. Ask the notary who handled your purchase, or check your own papers. A clear deed beats appearances.
Visible signs
Some clues point to an answer. The foundations and the thickness of the wall, the position of the floor and roof beams, the slope of the top of the wall, or traces of construction on each side can show who owns it. A professional, such as a surveyor or an architect, reads these signs better than a private owner.
The cadastral plan
The cadastral plan shows plot boundaries, but it does not prove ownership of a wall by itself. It gives an indication, not a title. Do not rely on it alone before starting works or signing a sale.
The presumption and time
Without a title or a contrary sign, the law presumes that a wall separating two buildings is shared. The presumption falls if a deed or a sign proves the opposite. In some cases, long and peaceful possession can also count. The conditions are strict, so ask a notary for advice before using it as an argument.
Who pays for maintenance and works?
In principle, the owners of a shared wall split the cost of upkeep and repair in proportion to the benefit each one gets. For a private wall, the owner pays alone.
Here are the most common situations:
- Repair of a wall in poor condition: both neighbours contribute, once they agree on the works and on the quote.
- Damage caused by one neighbour: the person who caused it bears the cost.
- Works that only suit one neighbour, such as raising or strengthening the wall: the person who asks pays, and must respect the other's rights.
- Insulation or render on one neighbour's side only: that neighbour handles it, unless agreed otherwise.
The good habit is to put the agreement in writing. An exchange of letters, or a quote signed by both parties, avoids disputes that often come back when you sell. If the neighbour refuses or does not reply, an amicable solution is the best first step. After that, you can turn to a legal professional or the justice of the peace.
Planning rules depend on the Region and the municipality. Before touching a wall, for example to raise it or open a window, ask your municipality whether a permit is needed.
Buying out the party wall: how it works
Buying out a party wall means buying half of a neighbour's private wall so that you become a co-owner. The Civil Code allows this under the conditions set by law, for a price that reflects the value of the wall.
This mostly interests an owner who wants to lean on the neighbour's wall, for example to build against it. The usual steps are these:
- Check that the wall is really private, using the deed and the signs on site.
- Have the value of the wall assessed, possibly by an expert.
- Offer a price to the neighbour and discuss the share to pay.
- Have the agreement recorded in a notarial deed, so that it can be relied on and found at a future sale.
The key point is the deed. A buy-out agreed verbally, or by a simple bank transfer, protects neither the buyer nor the future buyer of the house. The notary drafts the deed and has it registered, and the wall then appears in the titles. The exact costs and price depend on each case. Ask a notary for a quote rather than relying on a general figure.
The neighbour is not always obliged to sell in every situation, and special rules exist depending on the state of the wall and the planned use. Have your case checked before starting works.
What a party wall changes when you sell
A party wall changes the price very little in itself. But a poorly documented wall, or a dispute with the neighbour, can slow a sale or lower an offer. A clear file reassures the buyer.
Before you list the house, gather these items:
- the property deed and, if one exists, the deed of the party wall buy-out;
- written agreements with the neighbour about works and their cost;
- invoices for maintenance or repair of the wall;
- permits linked to works on the wall.
A serious buyer asks about the state of the wall, damp on the neighbour's side and shared works. These questions often come up when the offer is made. See our guide on making an offer on a house to understand what a buyer checks. If you sell, answering these questions in advance avoids renegotiation.
The shape of the house also weighs on value, much more than the status of the wall. A semi-detached or detached house cannot be compared with a terraced one. Markets and price levels differ. To place a property, compare it with houses in the same municipality. For example, look at the house pages for Uccle, Ixelles, Saint-Gilles or Brussels, where dense building makes shared walls common. On the outskirts, look at La Hulpe or Wezembeek-Oppem. In Wallonia, compare Seraing and Bastogne.
To get a value for your own house, whether terraced, semi-detached or detached, use the online estimate for your municipality. It starts from local market data. You can then refine it with the details of the wall and any works.
Frequently asked questions
What does the Belgian Civil Code say about shared walls?
The Civil Code presumes that a wall separating two buildings is shared, unless a title or a sign says otherwise. This presumption applies when no deed settles the matter, and a clear title or sign overturns it.
What distance must you keep from a neighbour when building?
The distance depends on the Region, the municipality and the type of opening or building. There is no single rule for the whole of Belgium, so ask your municipality's planning department before you build.
What is the difference between a terraced and a semi-detached house?
A terraced house shares its side walls with its neighbours, while a semi-detached house shares only one wall, with a single neighbour. Whether the wall itself is shared is checked in the property deed.
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