Damp in a rental property: liability in Belgium
Liability for damp in a rental property in Belgium. Causes, cost allocation, tenant remedies and landlord obligations.
Causes of humidity in a rented dwelling
Humidity is one of the most common problems in Belgian rental properties. Identifying the source is essential to determine who must pay for repairs.
Types of humidity
| Type | Source | Responsible party |
|---|---|---|
| Rising damp | Soil, foundations | Landlord |
| Infiltration | Roof, facade, windows | Landlord |
| Condensation | Lack of ventilation | Tenant (often) |
| Pipe leak | Plumbing | Landlord (built-in) |
| Water damage | Accident, negligence | Depends on source |
For water damage specifically, see our guide on water damage in a rental.
Allocation of responsibilities
At the landlord’s expense
- Treatment of rising damp (injection, drainage)
- Roof and facade repair
- Replacement of non-weatherproof windows
- Installation or improvement of ventilation
- Treatment of structural mould
At the tenant’s expense
- Daily ventilation of the dwelling (airing)
- Correct use of the extractor hood and existing mechanical ventilation
- Not drying laundry indoors without ventilation
- Prompt reporting of any humidity problem
- Cleaning air vents
Ambiguous cases
Condensation can result from a building ventilation defect (landlord) or inadequate use (tenant). An independent expert can determine the cause. For general obligations, see our guide on the landlord’s obligations.
Solutions and costs
Structural treatments (landlord)
| Solution | Indicative cost | Effectiveness |
|---|---|---|
| Rising damp injection | 2,000 - 6,000 EUR | Good |
| Perimeter drainage | 5,000 - 15,000 EUR | Excellent |
| Roof/facade repair | Variable | Excellent |
| Mechanical ventilation installation | 3,000 - 6,000 EUR | Good |
Tenant actions
- Ventilate 10-15 minutes per day (even in winter)
- Use an electric dehumidifier
- Do not place furniture against external walls
- Use the extractor hood when cooking
For renovation grants, see our guides on grants in Brussels and Wallonia.
Tenant’s remedies
If the landlord does not act
- Report the problem by registered letter with photos
- Request a professional assessment (shared costs or at the landlord’s expense)
- Send a formal notice with a reasonable deadline
- Contact the regional housing service for an inspection
- Refer to the justice of the peace to obtain works and a rent reduction
What the judge can decide
- Order works within a fixed deadline
- Grant a rent reduction for the duration of the problem
- Pronounce lease termination if the dwelling is uninhabitable
- Award damages
Document everything: dated photos, correspondence, abnormal heating bills, medical certificate if there is a health impact. Also see our guide on the property inventory.