Rental price indexation

To index the rent (and if the lease does not exclude it), the landlord must comply with regional rental legislation, which includes: 

• Opens in new windowregistering the lease agreement
• providing the tenant with an energy performance certificate (EPB) for the rental property

If indexation is allowed, the rent can be adjusted annually, at the earliest on the anniversary date of the lease coming into force. 

Indexation is not automatic; the landlord must request it in writing from the tenant. 
This request only has retroactive effect for the three months preceding the month of the request. 

Indexation is always based on fluctuations in the "health" price index. 

To calculate the amount of the indexed rent, the following formula is used (Article 1728bis of the old Civil Code): 

(base rent x new health index)/initial health index

Where: 

• the base rent is the amount specified in the lease agreement; 
• the initial index is the health index of the month preceding the date on which the contract was signed; 
• the new index is the health index of the month preceding the anniversary date of the lease coming into force 

The index tables are available on the FPS Economy Opens in new windowStatbel website. 

There is also an indexed rent calculator. 

Until 13 October 2023, rent indexation for energy-intensive properties was subject to restrictions. 

From 14 October 2023, indexation for rental properties with an EPB certificate rated E, F and G is once again permitted, but using an adapted formula.

You must Opens in new windowapply a correction factor if your property meets the following 3 criteria: 

1. The lease took effect before 14 October 2022. 
2. The EPB certificate for the property is E, F or G. 
3. The property is rented on the private or public market (including properties rented through the Public Centre for Social Welfare (PCSW), the municipality, a social rental agency or the Land Management Agency (Régie Foncière)). Properties rented by public service property companies: (SISP) and the Housing Fund are not affected. 

An Excel tool is available to help you calculate indexation of rent.