Residential, retail, office, warehouse or parking: every lease type has its own rules. Here is what changes depending on what you let.
The residential lease is the most common and most regulated case. It falls under the Region where the property is located, with distinct rules in Flanders, Brussels and Wallonia. It is also the only type where the energy certificate can limit indexation, through a correction factor in Flanders and Brussels. Registering the lease is free and compulsory, and indexation must be requested in writing on the anniversary date.
A studio let as a main residence follows the same rules as an ordinary apartment. A student room, however, falls under a separate regime: in Flanders student leases have their own provisions and are generally not indexed during the term, since they are concluded for a fixed period of one year. Always check what your contract provides before indexing.
Commercial leases are governed by the federal Commercial Tenancy Act rather than the regional decrees. The indexation formula is the same, but the initial index always corresponds to the month before signing — the Flemish 2019 rule on entry into force does not apply here. No EPC correction factor applies to retail premises. Indexation remains annual, on the anniversary date, and must be requested in writing.
An office falls under ordinary lease law, unless it is used mainly for retail trade. The calculation is identical to that of retail premises: initial index for the month before signing, no energy correction. Many office leases also include a fixed service charge that may or may not follow indexation. Our calculator explicitly separates indexable charges from fixed charges.
Residential, retail, office, warehouse or parking: every lease type has its own rules.
A warehouse, hall or workshop is generally let under ordinary law. Indexation follows the standard formula based on the health index, with no EPC involvement. These leases often have longer terms and specific clauses on maintenance or works. Such clauses do not affect the indexation calculation itself, but may determine how the accompanying charges are shared.
A garage or parking space let separately is not a residential lease: it falls under ordinary law, even if the tenant lives next door. Indexation follows the standard formula with no EPC condition. If the garage is let together with the home under a single contract, it forms part of the residential lease and follows those rules. The distinction matters, because it determines which initial index applies.
Legally, only one distinction is decisive: residential lease or not. For residential leases the initial index may depend on the date the lease took effect (the Flemish rule since 2019) and an EPC correction factor may reduce the indexation. For all other types — retail, office, warehouse, parking — the initial index follows the signing date and no energy correction applies. The resulting increase is therefore often higher.
You do not need to remember these differences. When registering a contract you indicate the property type and Region; the system then applies the correct rule. A landlord with an apartment in Ghent, a shop in Brussels and a garage in Namur manages everything from the same dashboard, with each lease indexed under its own regime, on its own anniversary date.
Enter your base rent, start date and region and see straight away what you may charge this year. Based on the official health index, with the Flemish EPC correction applied automatically.
Go to the free calculator →