Rent indexation calculator for Wallonia
Calculation compliant with the Walloon decree of 15 March 2018 and the federal Law of 6 August 1993. The capping window ended on 31 October 2023, but a permanent adapted method remains for capped EPC D-G leases (decree of 19/10/2022).
A few details.
The exact result.
Property region, lease dates, initial rent, EPC class. The calculation runs instantly.
The Walloon legal context in 2026
Wallonia has gone through two successive phases regarding rent indexation:
- 2022 — 31 October 2023: application of an EPC corrective coefficient to limit the indexation of energy-inefficient properties (anti-inflation measure).
- Since 1 November 2023: end of the capping window — permanent adapted method for capped EPC D-G leases (decree of 19/10/2022, still in force), federal standard calculation for the others.
Concretely, in 2026, the indexation calculation for a Walloon rent follows the federal formula for most leases, but EPC D-G leases capped during the 2022-2023 window remain subject to the permanent adapted method. The calculator automatically identifies the right regime based on the date and the EPC.
Historical EPC coefficients (reference)
D-G leases with an anniversary in the 11/2022-10/2023 window: indexation computed from the window's adapted rent (decree of 19/10/2022). Other leases: 100%.
These coefficients correspond to the capping window (ended on 31 October 2023). For capped leases, they determine the adapted rent that serves as the basis for the permanent adapted method.
Conditions to be met
- Lease registered with the competent registration office
- Written request to the tenant (simple letter or registered mail)
- One indexation per year, on the anniversary of the effective start date
- Retroactivity limit: 3 months
Frequently asked questions — Wallonia
Does the EPC still apply in Wallonia in 2026? + −
Yes, for certain leases. The capping window ended on 31 October 2023, but the decree of 19 October 2022 (still in force) provides a permanent adapted method for EPC D-G leases capped during the window: indexation rebased on the adapted rent of the window. Other leases follow the federal standard formula.
Which legislation governs indexation in Wallonia? + −
The Walloon decree of 15 March 2018 on residential leases, supplemented by the federal mechanism of the Law of 6 August 1993. The Walloon Public Service (SPW) is the competent regional authority.
My Walloon lease was signed in 2022 with EPC F: what happens? + −
During the capping window (1 November 2022 → 31 October 2023), indexation of an EPC F lease was frozen. Since 1 November 2023, your lease falls under the permanent adapted method of the decree of 19 October 2022: indexation rebased on the adapted rent of the window, starting index = month preceding the in-window anniversary. The calculator applies this method automatically.
On what date does indexation take effect? + −
On the anniversary of the lease's effective start date (not the signature). You must notify the tenant in writing — a simple letter is legally sufficient, but we recommend registered mail to keep proof.
How many months of arrears can I recover? + −
Three months maximum. Beyond that, the unclaimed indexation is permanently lost. Belgian law does not allow retroactivity beyond this limit, even if the lease is valid and the calculation correct.