Antoine HORENBEEK
Adding a terrace without a permit may seem trivial, but this common mistake can be costly. In Belgium, any construction or extension of a terrace is subject to strict regulations, and a simple omission can result in sanctions or an obligation to demolish. It's essential to check whether authorization is required according to the surface area, height or location of the work being carried out.
This article explains when planning permission is required, the steps to take in the event of infringement, and practical solutions for rectifying the situation quickly and correctly.
In Belgium, planning permission is a prerequisite for certain types of building work. It is generally issued by the commune, sometimes by the Region, depending on the scale or nature of the project.
This document guarantees that the planned work complies with local urban planning regulations: architectural integration, heritage preservation, environmental impact, etc. It applies to any major modification to a building or its immediate surroundings: new construction, transformation of an existing structure, and of course, the installation or modification of a terrace.
Each Belgian region has its own regulatory framework.
In Wallonia, the Code du Développement Territorial (CoDT) applies. In Brussels, it's the Règlement Régional d'Urbanisme (RRU), while in Flanders, it's the VCRO. These rules cover a number of parameters: terrace dimensions, materials used, layout, visibility from the public space and the location of the property (agricultural, classified, urbanized or non-urbanized zone). Municipalities can also reinforce these requirements via their local planning regulations or sector plans.
In a nutshell: regulations vary from place to place, so it's best to avoid improvising.
This applies to everyone involved, whether you're a private owner, an investor or a condominium manager. As soon as work is planned or carried out, urban planning obligations apply. In condominiums, any work carried out on a shared flat roof or shared space requires authorization from both the authorities and the general meeting of condominium owners.
In the event of non-compliance, the client (often the owner) can be held liable, even if the work was carried out by a professional.
To sum up: In Belgium, any construction or modification of a terrace must comply with specific rules, depending on the region and location of the property; planning permission may be required.
In certain cases, single-storey terraces can be built without a building permit. This is particularly true when they are located behind a dwelling, do not exceed 30 centimetres in height, and comply with local surface area restrictions.
If the terrace exceeds, for example, 40 m² (a common limit in Wallonia), or if it encroaches on a regulated green space or set-back strip, a permit application will be required.
The same applies to any terrace installed on the front facade: such work is almost always subject to authorization.
Antoine HORENBEEK
As soon as a terrace exceeds a few dozen centimetres in height, it enters a much stricter regulatory zone.
In the Walloon region, the threshold is 60 centimetres; in Brussels, it varies around one metre in height, especially if the terrace is visible from the public space. A suspended construction - such as a balcony or terrace attached to a facade - will systematically require planning permission, and often the intervention of an architect to guarantee stability and proper integration with the existing building.
Adding a few square meters to a terrace, even if it's already existing and authorized, is not trivial from an administrative point of view. In practice, the extension is treated as a new construction, and therefore subject to the same rules as if starting from scratch.
In addition, public authorities may require verification of the original permit: if nothing has ever been regularized, an application will have to cover the whole thing. Beware, too, of secondary effects: land levelling, drainage modifications, pavement changes... All these can have regulatory consequences.
Sometimes considered incidental, these elements can also trigger a permit requirement. A modern railing visible from the street, a metal staircase in the façade, a lean-to pergola or an automatic lighting system: each addition is examined according to its visual and structural effects, and its integration into the environment.
The presence of a permanent roof or covering also transforms a terrace into a semi-enclosed space, which modifies its urban classification. And a change of nature often requires a permit.
In short: Whether your terrace is on the ground, raised or extended, a permit may be required depending on its height, surface area or visual impact.
For similar examples, see the steps required to install a veranda in this article on obtaining a permit for a veranda.
Three technical elements are systematically analyzed: height, surface area and right-of-way. An unobtrusive, slightly elevated terrace will sometimes pass under the administrative radar. But as soon as a certain scale is reached - in height or surface area - authorization becomes unavoidable.
These criteria make it possible to assess potential risks to soil stability, water flow or impact on the neighborhood. These thresholds are not uniform: they depend on the commune, the region or even the neighborhood.
Building in an agricultural or protected area is not subject to the same rules as development in a town center. In the countryside, regulations are designed to limit diffuse urbanization, so terraces are particularly closely supervised.
In urban areas, the focus is on privacy, architectural coherence and potential nuisance. On listed sites, within a protected perimeter or a Natura 2000 zone, restrictions are more stringent: each modification is subject to a more in-depth analysis, sometimes even involving external experts.
If the terrace affects the load-bearing structure of the building, causes a visible change to the façade, or affects the environment (felling trees, sealing the soil, altering natural drainage), a permit is required.
In Brussels, a simple slab visible from the public space can be considered illegal without authorization. In Wallonia, depending on the case, an environmental declaration may be required even without a conventional permit, particularly if the work has ecological effects.
Each municipality has its own town-planning rules. They may impose materials, colors, maximum dimensions or distances from fences and adjoining boundaries.
A terrace that conforms to the regional code may be refused if it does not comply with local regulations. The local architect or heritage department is often consulted in such cases. And the same applies to more modest exterior works: as shown in this article on regulations around fences and walls.
In short: Height, surface area, location and local regulations are the key criteria for determining whether your terrace requires planning permission.
Building a terrace without planning permission, when required, exposes the owner to a planning violation. In this case, the authorities may decide to impose a regularization and/or impose an administrative fine.
In the most serious cases, this can lead to reinstatement or even complete demolition of the terrace concerned.
In Flanders in particular, daily penalty payments can be imposed for as long as the infringement persists. The degree of penalty often depends on the visible, repetitive and deliberate nature of the work.
To find out more on the subject, the dedicated article"Infraction urbanistique : tout savoir" answers the most frequently asked questions.
Antoine HORENBEEK
When selling a property, any failure to comply with town-planning regulations can hinder or even derail the transaction. The buyer is entitled to demand that the property is in order, and the presence of an unauthorized terrace can weigh heavily in negotiations.
If the irregularity is discovered in the context of a notarial deed, this can lead to delays in regularizing the situation, or even to litigation. On the other hand, a complaint from a neighbor, or a simple inspection by the municipal services, can be enough to trigger an official statement of offence and a whole administrative procedure.
There is a statute of limitations on planning offences, but beware: this does not mean that everything has been settled. Depending on the region, the statute of limitations ranges from 10 to 30 years, and can be suspended if the offence remains visible or reproducible.
In other words, an irregularly constructed terrace that is still in place after 15 years may not be time-barred if it still generates an impact. Logically, the only way to ensure the long-term legal security of a property is to regularize it in the proper manner.
To sum up: a terrace built without a permit can lead to penalties, jeopardize a property sale and remain a source of legal uncertainty until it is regularized.
Regularizing a terrace built without a permit doesn't have to be inevitable. It's a technical process, certainly, but one that's accessible with the right specialists at your side. It's better to move forward today than face an injunction or fine tomorrow that could have been avoided.
At Ubex, we take a close look at your situation, analyze your documents and manage the entire administrative process through to compliance. Make an appointment with our team, and let's talk about your file. That's the first clear step towards peace of mind.
In Wallonia, often from 40 m² upwards; in Brussels, regulations vary, but remain strict above a low height or if the terrace is visible from the street. Check the exact threshold with your local council.
No, it's even more restricted. A raised or suspended terrace will almost always require planning permission, and sometimes the involvement of an architect, even for a small surface area.
Start regularization as soon as possible. This usually involves surveying the existing situation, compiling a technical file (plans, photos, proof of stability), and submitting an application to the local authority.
Yes, for low terraces (less than 30 cm high) of small surface area, especially if they are invisible from the public highway. But beware: each commune may restrict this tolerance.
Author : CORNIL Olivier
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