The update of the Brussels rent grid, announced for 2026, was postponed in the spring. On 17 September 2026, the Constitutional Court dismissed the action brought by sector federations, without ruling on the grid itself. As a result, the current grid and the ban on abusive rents remain in force, and an updated grid is announced within two years.

What data is the current grid based on?

The indicative rent grid was established by an order of the Brussels Government of 19 October 2017, amended by orders of 30 June 2022 and 6 October 2022. These dates appear in Constitutional Court judgment no. 105/2026. According to RTBF, it relies on figures from 2017 to 2020. The applicants before the Court cited a last rent Observatory carried out between 2019 and 2020. The Brussels Housing Code defines the reference rent as the median rent shown in the grid. It is therefore the median of the grid’s model, not of the current market.

On 12 January 2026, the then Secretary of State for Housing, Nawal Ben Hamou, announced an update being prepared for that year. RTBF noted at the time that more than 17,000 leases had been registered through IRISRent since January 2025.

Why was the update postponed?

According to La Libre of 18 June 2026, the new Secretary of State for Housing, Karine Lalieux, refused to update the grid, and a landlords’ union responded by publishing its own grid. That union was a party to the action before the Constitutional Court. Karine Lalieux disputes its approach: in her view, its references are biased because the sample used is not representative of the private rental market.

The landlords’ central criticism concerns location: the grid would give it too little weight. Before the Court, the applicants, citing IGEAT, estimated that location weighs only 3%. The Brussels Government replied that differences in location are sufficiently taken into account.

What did the Constitutional Court decide on 17 September 2026?

On 17 September 2026, in judgment no. 105/2026, the Constitutional Court dismissed the real estate federations’ action against the ordinance of 10 April 2025, which brought the ban on abusive rents into force on 1 May 2025. It declared itself without jurisdiction over the grid itself, which stems from a Government order, and found the other complaints late. For an agency, nothing changes day to day: the reference rent remains mandatory in the lease, the presumption of abuse above +20% applies, and the joint committee can still be seized. We analyse the judgment in detail in our article on what ruling 105/2026 changes for your re-lettings.

The same day, according to RTBF, Karine Lalieux announced an update in two stages. The first will update the grid’s model on the basis of current data. The second will rely on collecting new, broader data. She said the work would take several months, with an updated grid expected within two years.

What does the law say about a rent above the grid?

The grid is not an automatic ceiling, but it is no longer merely indicative. The lease must state the property’s reference rent (Article 218, § 1, 4bis°). More than 20% above that rent, the rent is presumed abusive (Article 224). Only substantial comfort features intrinsic to the home or its surroundings can rebut that presumption. The “local market” or the rent of comparable properties are not among these features. Since 1 May 2025, the landlord may not propose an abusive rent (Article 224/1). The tenant can ask the joint rental committee for a non-binding opinion, then ask the justice of the peace for a revision, or go directly to the court.

What can property managers do now?

Simulate and record the reference rent for each lease

The current grid remains the only legal reference, however old. Every new Brussels lease should therefore start from a dated simulation on the regional tool, written into the lease and kept in the unit’s file. Coefficients published by landlords’ organisations have no legal value.

Document what justifies a gap

If the rent is more than 20% above the reference rent, the file must contain the substantial comfort features that justify it: equipment, outdoor space, renovations, energy performance, with invoices and the EPC. Our article on the gap between the grid and the market details this documentation.

Follow the announced update

The new grid is announced in two stages, with no precise date. Each version will change reference rents, and therefore the 20% threshold, for new leases. An agency that keeps the simulation used for each lease will always know which reference applied at the signing date.

How does Seido help track these rents?

Managing several properties? Seido keeps on each unit’s record the rent charged, its history and the indexations applied, together with the lease documents. When the framework changes, each unit’s data is already in one place. See how Seido tracks deadlines and obligations under the Belgian framework.

For indexation during the lease, see also our guide to calculating rent indexation.

Frequently asked questions

Does judgment 105/2026 validate the rent grid?

No, it does not rule on it. The Constitutional Court declared itself without jurisdiction over the criticism aimed at the grid, which stems from a Government order rather than an ordinance. It found the other complaints late. The action is dismissed, which leaves the ban on abusive rents in force since 1 May 2025.

When will the new grid be available?

No precise date has been set. On 17 September 2026, Karine Lalieux announced work in two stages, first an update of the model, then a broader data collection, with an updated grid expected within two years. Until then, the current grid remains the legal reference for every new Brussels lease.

Are current leases affected?

Yes. Since 1 May 2025, the tenant may request the revision of an abusive rent; this also applies to current leases (La Libre, 18 June 2026). The retroactive effect is limited: the revision takes effect at the earliest four months before the date of the court claim. Minimum periods also apply at the start of the lease, depending on its duration.

Sources and references

Last updated: September 2026. This article is provided for information purposes only and does not constitute legal advice. For any specific situation, consult a real estate law professional.