Quick answer

A primary residence lease can be converted to a commercial lease, but this requires terminating the existing lease, the landlord’s explicit consent, and signing a new commercial lease under the Act of 30 April 1951. A planning permit is usually required for the change of use.

Primary residence leases and commercial leases are governed by entirely different legal frameworks. A primary residence lease benefits from strong regional tenant protections (regulated duration, limited rent increases, restricted termination grounds), while a commercial lease follows federal law with its own set of rules (9-year minimum, renewal rights, eviction indemnity).

A simple addendum cannot achieve this conversion — a new contract must be drawn up.

Procedure and requirements

The conversion process involves several steps:

  1. Mutual agreement to terminate the primary residence lease (or serve proper notice)
  2. Planning permit application for change of use from residential to commercial
  3. New commercial lease drafted and signed (minimum 9-year duration)
  4. Registration of the new lease with the SPF Finances
  5. Insurance updates for both landlord and tenant
  6. Co-ownership approval if applicable (general assembly vote)

The termination of the primary residence lease must follow the applicable rules:

  • Tenant-initiated: 3 months’ notice, possible indemnity depending on timing
  • Mutual agreement: both parties sign a termination agreement (no notice period required)
BailBelgique tip

BailBelgique can generate both the termination agreement for the existing lease and the new commercial lease, ensuring a smooth legal transition.

The conversion has significant legal and fiscal consequences:

AspectPrimary residence leaseCommercial lease
Governing lawRegional housing legislationAct of 30 April 1951
Minimum duration1 year (short-term) or 9 years9 years
Taxation of landlordCadastral income + 40%Actual rent received
Renewal rightAutomatic tacit renewal3 renewals of 9 years (on request)
Eviction indemnityNone (limited notice rules)1 to 3 years of rent

The tax impact is particularly notable: the landlord’s tax burden typically increases because actual rental income (minus deductions) is used instead of the favourable cadastral income base.

Regional specifics

Brussels-Capital Region

Brussels requires a planning permit (stedenbouwkundige vergunning / permis d’urbanisme) for any change from residential to commercial use. The PRAS (Regional Land Use Plan) determines the permitted functions per zone.

Walloon Region

A planning permit is required under the Walloon Planning Code (CoDT). The sector plan (plan de secteur) determines whether commercial use is permitted at the property’s location.

Flemish Region

In Flanders, a change of function (functiewijziging) requires a planning permit under the Flemish Spatial Planning Code (VCRO). Some minor changes may benefit from exemptions.