Technical and regulatory aspects to consider for the renovation of building facades and roofs

Renovating the facades and roofs of a building is not just a matter of aesthetics or functionality—it’s an intervention that can have significant regulatory implications. In Belgium, such works often require building permits, and ignoring the regulations may result in penalties or an obligation to restore the original state.

This distinction is crucial:

• Primary facades: Any substantial modification requires a full building permit, known as an omgevingsvergunning.

• Secondary facades: These can be modified through a simplified procedure, referred to as melding.

What Is considered a “substantial modification”?

We’re not talking about routine or extraordinary maintenance, but rather interventions that alter the architectural appearance of the building:

• Change of materials or colors

• Modification of openings (windows, doors, glass panels)

• Addition of new architectural elements

  
  

If the building faces the street and external insulation is planned, it’s essential to check local regulations.

Some municipalities impose strict limits on the thickness of the insulation package (e.g. Antwerp: maximum 14 cm, including the external finish).

Other municipalities impose restrictions on finishing materials (e.g. Duffel does not allow plaster finishes in certain zones).

These limitations aim to preserve urban alignment and the aesthetic of public streets.

Roofs could be also a critical element.

Modifications that may require a building permit include:

• Addition of skylights or roof windows

• Change in the overall height of the building (e.g. due to insulation)

• Change in roofing material or color

• Structural alterations to the roof framework

In these cases, the intervention is no longer considered “maintenance” but a true building transformation, subject to authorization.

Before starting any work on facades or roofs, it is advisable to:

• Consult the municipal building regulations

• Check whether the building is subject to landscape or historical constraints

• Rely on a certified technician to prepare the building permit application

Respecting the regulations not only avoids legal issues but also ensures a harmonious and lasting result.

Contact us for personalized advice: we listen to your needs and guide you toward the most suitable choices for your project.