Rent indexation in Wallonia: everything you need to know
In Wallonia, residential rent indexation is governed by article 26 of the decree of 15 March 2018 on residential leases. The EPC limitation period ended on 31 October 2023, but the leases it affected (EPC D to G or no certificate) have since followed a special calculation method.
In short: in Wallonia, indexation is annual, on the anniversary of the lease's effective start date, for written and registered residential leases. Since 1 November 2023, leases rated EPC D to G or without a certificate that had an anniversary during the 2022-2023 limitation period follow a special calculation method (adapted rent); the others follow the ordinary formula, at 100%.
The rules of rent indexation in Wallonia
The Walloon decree of 15 March 2018
The decree of 15 March 2018 on residential leases is the regional framework for residential leases in Wallonia. Its article 26 governs rent indexation; its article 57 limits the retroactivity of a late request to three months.
The ordinary formula is the same as in the two other regions: base rent × new index ÷ starting index, using the health index. The Walloon specificity lies in the decree of 19 October 2022 (Belgian Official Gazette of 3 November 2022, in force on 1 November 2022), which amended that article 26: an EPC-based limitation of indexation from 1 November 2022 to 31 October 2023, followed by a special calculation method for the leases concerned (see below). This decree has not been repealed.
Conditions to be met
The landlord may index the rent, subject to several cumulative conditions:
- Written, registered lease. Without registration, indexation is not due — the tenant can legitimately refuse it.
- Written request to the tenant (simple letter or registered mail). Indexation never applies by itself.
- Anniversary date of the lease's effective start: indexation cannot take effect any earlier.
- Once a year only.
The EPC certificate is not a general condition for indexing in Wallonia (unlike in Brussels): it only determines the calculation method for certain leases. The indicative rent grid is not binding and has no effect on indexation.
Periodicity (annual only)
Indexation can be requested each year on the anniversary of the effective start date of the lease. Two dates therefore matter: the signature of the lease sets the starting index (that of the month preceding the conclusion of the lease); the effective start sets the anniversaries, and hence the new index (that of the month preceding the anniversary). If you request indexation late, retroactivity is limited to the 3 months preceding the month of the request (art. 57 of the decree): earlier months are lost.
The role of the EPC since 2022
From 1 November 2022 to 31 October 2023, Wallonia limited — like Brussels and Flanders, each with its own rules — the indexation of energy-inefficient properties. During that period, a property rated EPC A, B or C could be indexed at 100%; an EPC D at 75% of the increase; an EPC E at 50%; an EPC F, G or a property without a certificate could not be indexed. The resulting rent is called the adapted rent.
Walloon EPC table: the current regime
D-G or no-certificate 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%.
The 2022-2023 percentages no longer apply to indexations after 31 October 2023: they served to set the adapted rent. To check an indexation from that period, the calculator applies them automatically based on the requested indexation date.
Since 1 November 2023: a special method for EPC D to G leases
Since 1 November 2023, all Walloon rents can be indexed again — but not all in the same way. For leases that took effect before 1 November 2022, whose property is rated EPC D, E, F or G or has no certificate, and which had an anniversary during the 2022-2023 period, the decree of 19 October 2022 imposes a special calculation method, until the end of the tenancy: the base rent becomes the adapted rent of that period, and the starting index becomes the health index of the month preceding that anniversary. A favourable label obtained after renovation allows a return to full indexation (Constitutional Court, ruling no. 64/2024 of 20 June 2024, which also confirmed that the method covers dwellings without a certificate). Classes A to C and more recent leases follow the ordinary formula, at 100%.
Official example from the Walloon administration (SPW): rent of €600, lease signed in September 2019, effective 1 November 2019, EPC E. Adapted rent on 1 November 2022: €665.24; on 1 November 2023: 665.24 × 128.30 ÷ 127.92 = €667.22 (versus €705.79 with the ordinary formula). Detailed calculation on our EPC Wallonia page.
How to find your EPC?
To know whether your lease falls under the special method, you need the property's EPC class. To find it:
- Check your lease and its annexes
- Contact the certified assessor who issued the certificate
- Request a copy from the notary if the property was purchased with an EPC
- Have a new EPC certificate issued by a certified assessor
How to calculate your indexation in Wallonia
Our Wallonia calculator automatically applies the ordinary formula, the 2022-2023 EPC percentages for indexations in that period, as well as the special method for the leases concerned (EPC D to G or no certificate).
Worked example (Walloon lease concluded on 20 May 2021, effective 1 June 2021, rent €800, EPC B, indexation on 1 June 2026):
Starting index (April 2021, month preceding the conclusion of the lease): 110.93 — New index (May 2026, month preceding the anniversary): 139.22
Indexed rent = 800 × (139.22 ÷ 110.93) = €1,004.02
Pitfalls to avoid
- Confusing the signature date (which sets the starting index) with the effective start date of the lease (which sets the anniversaries)
- Using the smoothed health index instead of the raw one (the smoothed is for wages, not rents)
- Claiming more than 3 months of retroactivity (art. 57 of the decree)
- Indexing an unregistered lease (indexation is not due)
- Applying the ordinary formula to a lease rated EPC D to G or without a certificate that falls under the special calculation method
- Forgetting to send the written request to the tenant
What to do if the tenant refuses the indexation?
A Walloon tenant can refuse an indexation for several legitimate reasons: unregistered lease, indexation beyond 3 months retroactive, miscalculation, or simply not having received the notification letter. Before any judicial dispute:
- Verify your calculation with our calculator — an error on your side is more frequent than one might think.
- Re-notify by registered mail with acknowledgment of receipt, motivating it and attaching the calculation detail (our notification PDF is designed for this).
- If blocked, refer to the justice of the peace of the property's commune. The procedure is inexpensive and requires no lawyer; the time to a decision varies by canton.
Indexation of Walloon rents in 2026
Statbel's health index evolves monthly. In 2026, it rose from 137.37 in January to 140.30 in August (base 2013 = 100), compared with 135.64 in August 2025. A lease concluded in spring 2021 and indexed at 100% has seen its rent rise by about 25% in five years, as in the example above (€800 → €1,004.02).
To track the evolution month by month and anticipate upcoming indexations, see our health index table updated daily from Statbel.
Frequently asked questions — Wallonia
When can a rent be indexed in Wallonia? + −
Once a year, at the earliest on the anniversary of the lease's effective start date. The lease must be in writing and registered, and the indexation must be requested from the tenant in writing.
Does the EPC still apply in Wallonia? + −
Yes, for one category of leases. The limitation period ended on 31 October 2023, but leases that took effect before 1 November 2022, rated EPC D, E, F, G or without a certificate, and that had an anniversary between 1 November 2022 and 31 October 2023, have since followed a special calculation method, until the end of the tenancy: the calculation starts from the adapted rent of that period. Classes A to C and more recent leases follow the ordinary formula, at 100%. The EPC certificate is not a general condition for indexing in Wallonia.
Which index should I use? + −
The raw health index published monthly by Statbel. This is the index that excludes volatile products (alcohol, tobacco, fuel) — it is NOT the smoothed health index used for wages.
What if the tenant refuses the indexation? + −
First send a motivated registered letter. If the disagreement persists, the justice of the peace decides upon simple petition, at modest cost and without a mandatory lawyer.
My Walloon lease dates from 2019: can I index retroactively? + −
Not beyond the 3 months preceding the month of your written request (art. 57 of the decree of 15 March 2018). For earlier months, the unclaimed indexation is lost.
My lease is not registered: am I entitled to index? + −
No. Registration is a precondition. Without registration, indexation is not due and the tenant can legitimately refuse it.
Is registered mail required for the indexation notice? + −
Not legally mandatory — a simple letter is sufficient. But we strongly recommend it to keep proof of dispatch in case of dispute.
Does the Walloon decree of 2018 apply to my commercial lease? + −
No. The decree of 15 March 2018 only covers residential leases. The indexation of a commercial lease follows other rules and most often depends on a clause in the contract.
Going further
- Wallonia calculator
- Methodology of our calculation
- Health index table
- Comparison with Brussels
- Comparison with Flanders
Page updated on 18/9/2026. Sources: Walloon decree of 15 March 2018 on residential leases (art. 26 and 57), Walloon decree of 19 October 2022 (Belgian Official Gazette, 3 November 2022, Wallex), wallonie.be — Indexer un loyer, logement.wallonie.be — Indexation du loyer, Statbel. This content is informative and does not constitute legal advice. For any disputed situation, consult a lawyer or the justice of the peace.