Indexation applies to rent only
No, the indexation formula applies only to the base rent, not to charges. Charges evolve based on actual expenses or flat-rate provisions agreed in the lease. The landlord cannot index the charges.
The distinction is important:
- Base rent: subject to annual indexation via the health index formula
- Charges (real): adjusted based on actual utility bills and maintenance costs, with annual settlement
- Charges (flat-rate): fixed amount agreed in the lease, typically not adjustable during the lease term
How rental charges evolve
Belgian law provides two systems for charges:
Real charges (charges reelles): the tenant pays monthly provisions, and the landlord provides an annual settlement based on actual invoices. If actual costs exceed provisions, the tenant pays the difference. If costs are lower, the landlord reimburses.
Flat-rate charges (charges forfaitaires): a fixed monthly amount covering all charges. No annual settlement. The amount is agreed in the lease and typically cannot be changed during the lease term.
As a landlord, prefer real charges over flat-rate charges. Real charges allow you to pass on actual cost increases (energy, water, common area maintenance) to the tenant, while flat-rate charges expose you to the risk of rising costs without compensation.
Common confusion between rent and charges
Tenants and landlords sometimes confuse the total monthly payment with the base rent:
| Component | Indexable? | How it changes |
|---|---|---|
| Base rent | Yes (health index) | Annual indexation on request |
| Real charges | No | Annual settlement on actual costs |
| Flat-rate charges | No | Generally fixed for lease duration |
| Total monthly payment | Partially | Only the rent portion is indexed |
When calculating indexation, always use the base rent alone, excluding any charge amount.
Regional specifics
Brussels-Capital Region
The Ordinance of 27 July 2017 clearly separates rent from charges. The lease must specify the charge system (real or flat-rate).
Wallonia
The Decree of 15 March 2018 requires the lease to specify the charge system. Annual charge settlements must be provided within a reasonable timeframe.
Flanders
The Flemish Housing Rental Decree of 9 November 2018 imposes similar transparency requirements regarding the charge system.
Article 1728bis of the Belgian Civil Code applies exclusively to the base rent. Charge management is governed by the lease agreement and general contractual law.