On 4 April 2025, the Brussels Regional Parliament approved a new ordinance that has significant implications for landlords in the region. This ordinance ends the deferred implementation of certain provisions from the ordinance of 28 October 2021. Its main objective: combating excessive rents. The new rules will enter into force on 1 May 2025.

This measure applies to all lease agreements, including those signed before or on the date of its entry into force.
At the heart of this system is the Rent Assessment Commission, a neutral body with equal representation of landlords and tenants. The commission provides non-binding, yet objective advice on the fairness of a rent.
Requests are processed within two months. The commission’s opinions are publicly accessible and freely available on its website.
The commission may also act as a mediator and aims to encourage out-of-court settlements.
The reference rent is an indicative rental value based on objective parameters such as:
The primary aim of these reference rents is to provide prospective tenants and landlords with a clear picture of Brussels rental prices.
Since the end of 2021, landlords must include the reference rent in the lease agreement. As of November 2024, it must also be mentioned in advertisements.
An online simulator is available on the Brussels Region website to calculate the reference rent, including a 10% margin to allow for negotiation.
A rent is deemed excessive if it exceeds the reference rent by more than 20%, without quality defects or exceptional circumstances to justify the difference.
In such a case, the tenant may request a revision from the Rent Assessment Commission, and possibly also through the justice of the peace.
The ordinance provides different procedures depending on the duration of the lease:
After receiving the commission’s advice, the parties may reach an agreement through mediation. If this fails—or if the parties prefer—they may turn to the courts. The judge will decide based on fairness and may retroactively adjust the rent, up to four months prior to the request.
Note: if a landlord has previously had to revise an excessive rent for the same property, a new request may be submitted at any time during the lease. If the rent is again found to be excessive, the revised rent will apply from the first month of the lease.
The regulation also allows the judge to grant a rent increase when:
An increase is also possible when:
This mechanism is intended to encourage landlords to manage their properties sustainably and responsibly.
As a landlord in Brussels, you can no longer set your rental prices entirely freely. You must be aware that your rent can be reviewed if it is considered excessive. Not every excessive rent will be automatically revised, but you will now have to justify it.
The Real Estate team at Andersen is here to support you. Should you have any questions on this subject, please do not hesitate to contact our specialists at info@be.Andersen.com or +32 2 747 40 07.
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