The Brussels difference
This is the most important point in this article, and it is regularly misunderstood. The two regions do not set the same deadlines.
The Brussels scheme does not target purchasers alone. It applies to all owners, regardless of any transaction.
A long-standing owner, neither selling nor buying, is therefore concerned, unlike under the Flemish regime.
The deadlines are calendar-based rather than event-based, which means they run for everyone at the same time.
An intermediate milestone is set for the early 2030s, with a consumption ceiling to meet, followed by a long pathway towards a more demanding level.
Generalisation of the certificate is also programmed, by an announced deadline, which will document the entire stock.
The dual Walloon pathway
Wallonia combines two mechanisms, which distinguishes it from the other two regions. It layers a pathway on top of specific obligations.
An obligation tied to acquisition, requiring a given level to be reached within a period after transfer, with progressive tightening of the level required over the years.
A timetable of progressive prohibition, aimed at existing owners and successively rendering the poorest ratings inadmissible, at deadlines several years apart.
The final horizon is aligned with European objectives, with a high level expected by 2050.
That pathway was revised in late 2025, which makes earlier information obsolete.
| Region | Who is covered | Nature of the deadlines |
|---|---|---|
| Brussels | All owners, with no transaction | Calendar-based, the same for everyone |
| Wallonia | Owners under the two combined mechanisms | Long pathway plus specific obligations |
| Flanders | The purchaser after a transfer of ownership | Counted from the acquisition |
Penalties
They differ in their logic.
In Brussels, automatic penalties are announced from the early 2030s, with fines calculated by reference to the gap between actual consumption and the target, and to the size of the building.
That method of calculation is notable: it makes the penalty proportionate to the scale of the failure rather than flat-rate.
In Wallonia the penalty regime accompanies the pathway, with arrangements to be checked with the administration.
Why comparison between regions misleads
A technical trap affecting professionals working across regions. The vocabulary differs from one region to another.
The rating scales are not directly comparable. One grid may be more demanding than another to reach the same nominal rating.
Convergence is being considered between some regions, but it is not settled to date.
Practical consequence: a property rated D in one region does not necessarily show the same physical performance as one rated D elsewhere. This is developed in the article on energy assessments.
Why caution is warranted here
Three reasons specific to these two regimes. They relate to the calendar, the scope and the penalties.
They are more recent than the Flemish regime, therefore less settled and less documented by practice.
They have been revised recently, the Walloon pathway in late 2025 and the Brussels scheme since its introduction.
Sources diverge on certain dates, including serious professional sources, which reflects successive announcements rather than carelessness.
The position adopted in this guide is therefore deliberately cautious: set out the mechanisms, note the announced deadlines, and systematically refer to checking at source.
What this means for a professional
Four rules.
Never transpose Flemish reasoning to Brussels, the range of persons covered being different.
Inform long-standing Brussels owners, who often believe themselves outside the scheme.
Check dates with the regional source, secondary sources diverging.
Update before any commitment, these pathways having been amended recently and being liable to change again.
This article reflects the position of the rules at the date of checking and serves professional orientation. It does not replace technical advice or consultation of the regional administrations.