Rent revision in Belgium: legal conditions and procedure
Rent revision is a legal mechanism allowing the landlord or tenant to request a modification of the base rent during the lease, when new circumstances have caused the rental value of the property to change significantly. Not to be confused with annual indexation, which is an automatic adjustment linked to changes in the health index: revision is a substantial modification of the base rent itself.
In Belgium, revision is governed by regional legislation (Brussels ordinance of 2017, Walloon decree of 2018, Flemish Woninghuurdecreet of 2018). It can only occur at specific points in the lease — the end of each three-year period — and under strict conditions, notably a change in rental value of at least 20%. A landlord who wishes to increase the rent beyond indexation cannot do so unilaterally: they must follow the legal procedure and, in case of disagreement, refer the matter to the justice of the peace.
Legal conditions for revision
Rent revision is subject to cumulative conditions:
Condition 1: End of three-year period
The 9-year primary residence lease is divided into three periods of 3 years (three-year periods). Revision can only be requested at the end of each three-year period:
| Three-year period | Period | Window for revision request |
|---|---|---|
| 1st three-year period | Years 1 to 3 | Between the 9th and 6th month before the end (months 27 to 30) |
| 2nd three-year period | Years 4 to 6 | Between the 9th and 6th month before the end (months 63 to 66) |
| 3rd three-year period | Years 7 to 9 | No revision possible (end of lease) |
Condition 2: Change in rental value
The normal rental value of the property must have changed by at least 20% compared to the current rent, due to new circumstances. This change can be upward (revision by the landlord) or downward (revision by the tenant).
Circumstances justifying an increase of more than 20%:
- Significant improvement of the neighbourhood (new metro station, urban development)
- General increase in rents in the area
- Improvement works carried out by the landlord
Circumstances justifying a decrease of more than 20%:
- Deterioration of the neighbourhood (nuisances, shop closures)
- Deterioration of the property’s condition (if not attributable to the tenant)
- Loss of a facility or advantage (parking, garden)
Condition 3: Compliance with the procedure
The request must be submitted within the prescribed time window (between the 9th and 6th month before the end of the three-year period) and follow the formal procedure described below.
Rent revision procedure
The revision follows a multi-step process:
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Assessment of rental value: the landlord (or tenant) has the current rental value of the property assessed, based on the indicative rent grid (in Brussels), rental market prices or a property valuation.
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Calculation of the gap: compare the current rent (indexed) with the normal rental value. The gap must be at least 20%.
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Notification to the other party: send a revision request by registered post, between the 9th and 6th month before the end of the three-year period. The letter must indicate the new rent requested and the new circumstances justifying the revision.
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Amicable negotiation: the parties have the remaining period before the end of the three-year period to negotiate an agreement.
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Referral to the justice of the peace: in case of disagreement, either party can refer the matter to the justice of the peace to have the new rent determined. The judge may order an expert assessment to determine the rental value.
Deadlines to observe:
| Action | Deadline |
|---|---|
| Sending the request | Between 9 and 6 months before the end of the three-year period |
| Amicable negotiation | During the remaining period |
| Referral to the justice of the peace | No later than 6 months before the end of the three-year period |
| Effective date of the new rent | At the start of the following three-year period |
The new rent, whether agreed amicably or set by the judge, takes effect on the first day of the following three-year period. It will then serve as the basis for annual indexation.
Special case: revision after renovations
Rent revision is also possible when the landlord has carried out improvement works in the property, even outside the end of a three-year period. The conditions are however specific:
- The works must increase the rental value of the property
- The cost of the works must represent at least a certain proportion of the property’s value
- The works must not be simple maintenance repairs
- The landlord must be able to justify the cost of the works (invoices)
For a detailed analysis of the specific conditions for renovations, consult our dedicated page on rent revision after renovations.
Examples of works justifying a revision:
- Installation of a new fitted kitchen
- Complete renovation of the bathroom
- Replacement of window frames and EPC improvement
- Installation of a central heating system
- Roof and wall insulation
Works NOT justifying a revision:
- Routine maintenance repairs
- Like-for-like replacement of worn-out equipment
- Mandatory compliance work (electricity, gas)
- Painting and minor repairs
The distinction between improvement works and maintenance works is sometimes delicate. In case of doubt, the landlord can consult a property professional or seek the opinion of the justice of the peace through a conciliation process.