Building a conservatory changes the volume of your home. In Brussels, that means a planning permit is required in the vast majority of cases.
Do you need a permit for a conservatory?
Yes, in almost every case. A conservatory is an extension of the existing building, so it changes the building’s volume. Under Article 98 of the CoBAT (Brussels Spatial Planning Code), this work requires a planning permit.
There is no general exemption for conservatories, unlike small garden sheds.
Conditions and applicable rules
Your conservatory project will have to comply with:
- The RRU (Regional Urban Planning Regulation): building depth, footprint, height and setbacks
- Your municipality’s RCU (municipal urban planning regulation), if there is one
- The distances from the boundaries with your neighbours
- The requirements of any PPAS (special land-use plan)
- The rules for courtyard and garden areas (50% of the surface must remain permeable)
Do you need an architect?
Yes. Building a conservatory involves structural work and a change in volume. An architect is mandatory to design the plans and put together the permit application.
RRU constraints and party walls
Title I of the RRU requires, in particular:
- That the structure does not exceed the maximum permitted depth in the inner block area
- Compliance with the 45° plane in relation to the party walls
- Keeping a minimum permeable surface of 50% in the courtyard and garden area
If your project departs from the RRU, you will have to request a derogation as part of the permit application.
Energy performance (EPB)
Any conservatory that adds heated floor space is subject to the Brussels Region’s EPB (energy performance of buildings, PEB in French) requirements. Depending on the floor area, an EPB declaration or an EPB certificate may be required.
Steps to follow
- Contact your municipality’s planning department for a preliminary opinion
- Hire an architect to design the project and check it against the regulations
- Prepare and submit the planning permit application
- Wait for the decision (75 to 160 days)
- Display the permit and start work