In Belgium, a non-residential building whose heating or air conditioning exceeds 290 kW must have a building automation and control system (BACS). The rule is regional: it has applied in Brussels since 1 January 2025, and in Wallonia and Flanders since 31 December 2025. Flanders will lower the threshold to 70 kW by 31 December 2029 at the latest (S1, S2, S3).
Last checked: 9 November 2026
Belgium’s three regions, Brussels, Wallonia and Flanders, each set the requirement in their own legislation, with their own dates and details. The official texts are in French or Dutch: we keep their original titles below and summarise them in English.
Region, building type, power: your result appears after the third question.
The starting threshold is the same everywhere. The dates and the details are not.
| Criterion | Brussels | Wallonia | Flanders |
|---|---|---|---|
| Threshold | Heating or air conditioning above 290 kW | Above 290 kW useful nominal power, for heating or for air conditioning | 290 kW, heating and cooling counted separately; hydraulically connected installations are added together |
| Deadline | 1 January 2025, for new and existing buildings | 31 December 2025 | 31 December 2025, then 70 kW by 31 December 2029 at the latest |
| Mixed-use buildings | Covered if non-residential EPB units make up more than 50% of the floor area served | Covered if the non-residential or collective accommodation part (care homes, boarding schools; not blocks of flats) makes up 50% or more of the floor area | Check case by case |
| Legal basis | ‘Arrêté du 21 juin 2018’, Brussels order of 21 June 2018 | ‘Arrêté du Gouvernement wallon du 15 mai 2014’, Walloon Government order, art. 19/3 and annex C4 (French) | ‘Energiedecreet’, art. 11.1/1.2, and ‘Energiebesluit’, art. 9.4.1, the Flemish energy decree and its implementing order (Dutch) |
| Official source | Brussels Environment information sheet, in French (S1) | Consolidated text on Wallex, in force from 1 January 2026, in French (S2) | Flemish government page, in Dutch (S3) |
Last checked: 9 November 2026
Having controllers is not enough: the rules ask for specific functions.
(same requirements)
In the plant room, this means meters read by the controls, stored history, alarms that reach the technical manager, and controllers able to exchange data with the rest of the building over BACnet, Modbus or M-Bus.
In Flanders, the text names the owner or the holder of a real right over the building. It adds that in a shell-only let (‘casco’), where the tenant fits out the building, the tenant often carries the obligation (S3).
In Brussels and Wallonia, the texts we read do not say who is responsible. It is worth settling the point between owner and occupier before any work starts.
In Flanders, the requirement does not apply where it is ‘technisch, functioneel of economisch niet haalbaar’: not technically, functionally or economically feasible (S3).
In Brussels and Wallonia, we found no exemption in the texts we read.
Flanders has already set it: the threshold drops to 70 kW by 31 December 2029 at the latest (S3).
Brussels and Wallonia have published no date we could confirm. If your installation is between 70 and 290 kW in Brussels or Wallonia, the rule does not apply to you today, but it is worth keeping an eye on.
Many French-language results on BACS describe the French ‘décret BACS’. Its deadlines do not apply in Belgium: only the regional rules above do.
It is on the nameplate of the boiler, heat pump or chiller, and often in the latest service or inspection report.
Which brand, which controllers, a supervision system or not, meters read by the controls or not. Photos of the control panels and their labels are enough to start.
We compare what is in place with the functions your region requires, and tell you what is missing. [to confirm]
Last checked: 9 November 2026
Mainly non-residential buildings (offices, schools, shops, hotels, public buildings) whose heating or air conditioning exceeds 290 kW, in all three regions. In Flanders, the owner or the holder of a real right is responsible. In Brussels and Wallonia, the texts we read do not say.
The heating or air conditioning power shown on the nameplate of the boiler or chiller. In Wallonia, the text refers to useful nominal power. In Flanders, heating and cooling are counted separately, and hydraulically connected installations are added together: two 200 kW boilers on the same circuit count as 400 kW. If in doubt, we can read it on site. [to confirm]
In Brussels, yes if non-residential EPB units make up more than 50% of the floor area served. In Wallonia, yes if the non-residential or collective accommodation part makes up 50% or more of the floor area. Collective accommodation means housing with shared rooms or services, such as a care home or a boarding school; a block of flats does not count. In Flanders, we check case by case.
Not necessarily. A BMS that shows temperatures and alarms does not always provide the required functions: continuous monitoring and logging of energy use, comparison with reference values, detection of efficiency losses, alerts to the technical manager, and communication with other equipment. The meters, the history or the alerts are sometimes missing. We check what yours does and what needs adding.
Send us the region, the power rating and a few photos of the controls: we will tell you what the rule asks of your building, and what is missing.