Rent indexation

Health-index indexation, explained – then automated.

The right health index, the right reference month, the right PEB correction: that is what makes an indexation unchallengeable. Test yours below — free, without an account — with the real JAREMS engine and the official Statbel health index.

Free · no accountNo email asked — the calculation stays on this page, nothing is stored.
1. Country of the dwelling
2. The dates
Lease signatureSets the base index: the health index of the month before signature.
Lease entry into forceDetermines the anniversary date of the indexation — empty: signature date.
Last indexation appliedEmpty: none since signature — the simulator then quantifies everything that was missed.
Simulation dateThe date on which the calculation would be made — today by default.
3. The dwelling
Base rent of the lease (€, excl. charges)The rent frozen at signature — Belgian indexation is always calculated from it.
RegionDetermines the applicable EPC modulation.
EPC class (PEB)Depending on the region, a poorly rated dwelling gets a reduced indexation. In Brussels, the class is required to index.
Fill in your lease on the left: the full calculation detail — official indices, what you can claim, what you may already have lost — appears here.

🇧🇪 Belgium

Health index · Statbel
The formula

Base rent (frozen in the lease) × (health index of the month before the anniversary ÷ health index of the month before signature).

  • The health index is published monthly by Statbel; the ratio always applies to the base rent, never to the current rent.
  • Regional energy rule: for a lease that predates the 2022-2023 measures and a poorly rated dwelling, every indexation is multiplied by an official correction factor – classes E to G in Brussels and the German-speaking Community, D to G in Wallonia and Flanders. In Brussels, a rent cannot be indexed without an EPC certificate.
  • Indexation can only be claimed within the legal deadlines – the engine bounds the calculation in time.
Example
Base rent€850.00
Starting index (12/2021)115.60
New health index (12/2025)136.69
EPC correction factor (Brussels, class E)× 0.951950895
New rent amount€956.78+12.56%

🇫🇷 France

IRL · INSEE
The formula

Current rent × (IRL of the reference quarter ÷ IRL of the same quarter the previous year).

  • The IRL is published quarterly by INSEE; the reference quarter is the one set in the lease.
  • Dwelling rated EPC F or G: indexation frozen (Climate and Resilience law) – the engine blocks it automatically.
  • Regulated area: any breach of the rent cap is flagged for review before applying.
  • The review compounds year over year on the current rent.
Example
Current rent€850.00
IRL Q4 2024144.51
IRL Q4 2025145.65
New rent amount€856.70+0.79%
Nothing gets hidden

A calculation you can show is a calculation nobody challenges.

Every JAREMS indexation keeps the index used, its publication date and the full calculation detail. The letter sent to the tenant repeats these elements line by line – and the archive remains available years later, if the question comes back.

  • Health index ingested as soon as Statbel publishes it
  • Calculation dated, detailed and kept for audit
  • Proposal to approve: nothing applies without your agreement
  • Indexation letter generated with the calculation detail
Proof of the calculation Auditable
Index seriesHealth index – Statbel (official)
Reference periodDecember 2025
Energy rulePEB E (Brussels) – factor × 0.951950895
Calculation date03/01/2026

Detail kept with the lease · available at any time

Liked the simulation? JAREMS redoes it by itself, every year.

Jarems Lite is free up to 5 units, no credit card: register your lease, the engine watches every anniversary, calculates the health-index indexation, generates the letter — and nothing gets lost.

Calculate my indexation

Free up to 5 units · immediate, auditable result