New rent indexation rules in Wallonia: What changes for shared housing in 2026

Do you share a large house in Namur or a cosy apartment in Liège? Whether you are a host or a housemate, the question of rent indexation comes up every year. At Roomlala, we know how stressful and confusing this subject can be, especially since the recent energy reforms. In 2026, the Walloon rental landscape has well and truly digested the previous crises, but the rules left in their wake continue to dictate the law. Between the famous EPC (Energy Performance Certificate), the corrective mechanism, and the specifics of shared housing, it is sometimes difficult to find your way. We are offering you a complete, human-focused breakdown today to understand exactly how rent indexation in shared housing works in Wallonia this year. Follow the guide!

The end of the indexation freeze and the importance of the EPC in 2026

The return to indexation for all types of housing

Remember: at the height of the energy crisis, the Walloon government decided to freeze or limit rent indexation for housing considered to be energy-inefficient. The goal was to protect tenants against a double whammy: exorbitant energy bills coupled with a rent increase. Since 1 November 2023, this strict freeze has ended. Today, in 2026, the general rule is back: 100% rent indexation is once again authorised in Wallonia, regardless of the Energy Performance Certificate (EPC) score of your housing.

This measure marks a return to normal for hosts, who can once again adjust their rental income in the face of inflation. However, this return to normal does not mean the EPC no longer matters—quite the contrary. The Walloon legislature has put in place long-term safeguards to prevent tenants of poorly insulated properties from suffering a brutal rent increase that would make up for the 2022-2023 freeze year all at once.

At Roomlala, we always encourage transparency. For housemates, this means that an annual increase is now possible and legal, even if your room's insulation leaves something to be desired. For hosts, it is the assurance of being able to maintain the profitability of their property, provided they follow very precise calculation formulas.

It is therefore crucial to know the exact EPC score of the housing you occupy or are renting out. An EPC A, B or C certificate allows for standard indexation. However, if the shared housing is located in a building rated D, E, F, G or lacks a certificate, the rules of the game change thanks to what is known as the corrective mechanism, which is still fully applicable in 2026.

The corrective mechanism: how does it work?

The corrective mechanism is a specific mathematical formula introduced by the Walloon Region. Its goal? To smooth out the impact of the freeze year (2022-2023) for housing that is underperforming in terms of energy. If this mechanism did not exist, a host of an EPC F property could today apply indexation based on the cumulative inflation of recent years, which would cause an unsustainable rent increase for housemates from one month to the next.

In 2026, if your shared housing displays an EPC D, E, F, G or has no certificate, the host must use this corrected formula. Concretely, the calculation takes into account the health index of the month preceding the lease anniversary date, but applies a reduction factor proportional to the freeze period. This allows the rent to increase, yes, but in a much gentler and more controlled manner than with an EPC A, B or C.

Let's take a concrete example: imagine a shared house of three students in Mons, in a townhouse showing an EPC E. The base rent was 900 euros. Without the corrective mechanism, standard indexation might have pushed the rent up to 980 euros in 2026. Thanks to the corrective mechanism, the increase is reined in, and the new indexed rent will instead be around 935 euros. That is a major difference for a student budget!

This complex system requires great rigour. We regularly notice at Roomlala that hosts, in good faith, try to apply standard indexation to an EPC E property, ignoring the continued existence of this corrective mechanism in 2026. It is therefore the duty of each party to check the EPC letter before accepting or proposing a new rent amount.

Specific indexation rules for shared housing in Wallonia

A legal framework aligned with the main residence lease

Since 1 September 2018, Wallonia has had a specific legal framework for shared housing, finally recognising this increasingly popular way of living. What you need to know in 2026 is that the indexation rules applicable to shared housing leases are strictly identical to those for standard main residence leases. There is no preferential regime or penalty for housemates.

Whether you have signed a single lease (where all housemates are jointly liable) or individual leases for each room (often equated to a homestay or renting furnished rooms), the principle remains the same. Indexation can only occur once a year, at the earliest on the anniversary date of the lease agreement coming into force.

It is important to highlight that indexation applies to the rent excluding charges. The provisions for charges (water, gas, electricity, internet) are not indexed: they must be settled based on actual bills. At Roomlala, we always recommend clearly separating the base rent and the charges in the contract to avoid any confusion during the annual calculation.

A frequent use case concerns the replacement of a housemate. If an amendment is signed to acknowledge the departure of Julien and the arrival of Sarah, the anniversary date of the initial lease remains the reference for indexation. The host cannot take advantage of this change of tenant to index the rent at another time of the year or to bypass the rules related to the EPC.

The sine qua non condition: lease registration

Here is a vital piece of information that still escapes many market players in 2026: rent indexation for shared housing is only legally applicable if the lease agreement has been previously registered. This is an absolute condition imposed by Walloon law. An unregistered lease immediately deprives the host of their right to indexation.

Registering the lease is a free administrative procedure that must be carried out by the host within two months following the signing of the contract, via the MyMinfin online platform of the FPS Finance. This formality gives the contract a certain date and protects all parties. For housemates, it is the guarantee that their rights can be asserted against third parties (for example, in the event of the building being sold).

Let's imagine a concrete case: a host in Tournai has been renting a house to four young workers for two years. In March 2026, they send them a letter to index the rent. The housemates, well informed, ask for proof of lease registration. The host realises they have forgotten this step. Result: they cannot index the rent. They must first register the lease (potentially with a late fine) before being able to formulate a new request.

We therefore strongly advise you, upon moving in, to check that this formality has been completed. At Roomlala, we make a point of informing our hosts of their legal obligations to guarantee peaceful rentals without any nasty surprises for tenants.

Hosts and housemates: Procedures and points of vigilance

Indexation is never an automatic process. It is a crucial point of vigilance. The host must compulsorily formulate their indexation request in writing to the housemates. A simple oral agreement or an informal message is not enough from a legal perspective. We recommend sending a clear email with a read receipt, or better, a registered letter, detailing the exact calculation and the new amount due.

What happens if the host forgets to request indexation on the anniversary date? Walloon law is lenient but sets strict limits. Retroactivity of indexation is limited to the 3 months preceding the request. For example, if the anniversary date of the shared housing is 1 February, but the host only sends their request on 15 June, they will only be able to claim the indexed rent for the months of March, April and May, in addition to future months. The months of February and earlier are lost to them.

Another major point of vigilance concerns the validity of the EPC certificate. To benefit from standard indexation without the corrective mechanism (for example, if the host has carried out insulation work to go from an EPC E to an EPC C), the new EPC certificate must be valid at the precise moment of the indexation request. It is not enough to promise that the work is finished or that the certifier is coming.

Here is a typical use case: a host renovates their shared house in Louvain-la-Neuve in January 2026. The lease anniversary date is in March. If they have not received the official EPC document certifying class C before sending their request in March, they will have to apply the corrective mechanism linked to the old EPC. Paperwork must always precede action!

How to calculate indexation without making a mistake (and avoid disputes)?

The calculation of indexation is based on a strict legal formula that uses the evolution of the health index. The basic formula is as follows: (Base rent x New health index) / Base health index. The base index is that of the month preceding the signing of the contract, and the new index is that of the month preceding the anniversary date. However, with the introduction of the corrective mechanism for lower EPC ratings, this manual calculation has become a real headache.

Faced with this complexity, it is imperative to use the right tools. At Roomlala, we formally advise against trying to do the calculation yourself if your housing is subject to the corrective mechanism. The slightest decimal point error or the wrong choice of index can lead to unnecessary disputes between housemates and hosts, poisoning the atmosphere of the home.

The safest and most transparent solution is to direct all your efforts towards the official Belgian government calculator: the Statbel calculator (statbel.fgov.be). This online tool, which is free and updated in real time, automatically integrates the specific rules for Wallonia, including the parameters of the corrective mechanism linked to your housing's EPC score in 2026.

• Step 1: Gather your lease (for the date of signing and entry into force), the amount of rent excluding charges, and the EPC certificate.
• Step 2: Go to the Statbel website and enter this data into the simulator.
• Step 3: Generate the official PDF document provided by the site.
• Step 4: Attach this PDF to your written indexation request.