A home using 250 kWh/m² a year is labelled C in Flanders and Wallonia, but E in Brussels. A new technical analysis, built by BGBC members from across the building value chain, sets out what a common EPB scale would change in each region, and when the window to do so opens. It is now available to download in Dutch and French.
One letter, three meanings
The EPB certificate appears in every sale and rental listing, shapes renovation obligations and increasingly informs lending decisions. Yet label D covers homes up to 400 kWh/m² a year in Flanders, 340 in Wallonia and 210 in Brussels.
All three regions are now revising their EPB rules to transpose the revised EPBD, which requires a closed A-to-G scale. Every region must recalibrate its scale anyway, so harmonisation would shape a change that is already under way.
A fragmented approach creates complexity. A more aligned approach creates momentum.
What the analysis shows
Consumption (kWh/m²·yr) | Brussels | Wallonia | Flanders |
|---|---|---|---|
| 150 | C | B | B |
| 250 | E | C | C |
| 350 | G | E | D |
Calculation methods differ slightly between regions; the table shows the effect of the class thresholds alone.
In Brussels, renovation targets are set in kWh/m², so a new scale would only change how they translate into letters. In Wallonia and Flanders, obligations are anchored in the letters themselves. New thresholds would change the required level there, unless a conversion table and transitional rules are introduced.
An indicative estimate suggests a common scale would change the letter of about half of the Walloon and Flemish homes certified in 2024, and nine in ten in Brussels.
Feasible, and a window is opening
The directive already reasons at national level, and the three regional methods share the same logic, even if their parameters differ. Flanders plans a new instrument and label scale from 2030, and Wallonia has announced major changes to its method. Integrating a common scale now would spare citizens and professionals two successive changes.
A common scale implies no transfer of competence. Austria and Switzerland share a common tool while their regions keep their powers, and in Belgium existing cooperation instruments such as CONCERE could play that role.
The note also lists points of attention for policymakers, from conversion tables to financing and certifier training. It takes no position on the choices to be made: those belong to the administrations and policymakers who decide.
Built by the sector, open to all
The analysis was developed within BGBC's EPB Harmonisation Task Force, based on contributions from members across the building value chain. Like all Task Force deliverables, it is freely available for anyone to use.
Contact: Gilles Vanvolsem, Managing Director, gilles.vanvolsem@belgiangbc.be, +32 475 701 246
Download the technical analysis note "Harmonisation of EPB scales"