Renting a property not connected to the sewer system in Belgium
Can you rent a property not connected to the sewer network in Belgium? Sanitation obligations, septic tank, tenant disclosure and compliance.
Sanitation regulations in Belgium
In Belgium, the Regions define sanitation zones:
| Zone | Obligation | System |
|---|---|---|
| Collective sanitation zone | Mandatory sewer connection | Public network |
| Individual sanitation zone | Mandatory individual treatment | Septic tank or micro-station |
| Transitional sanitation zone | Future connection planned | Septic tank in the meantime |
Andre is in an individual sanitation zone: no public sewers are planned. The septic tank is the legal solution. He can rent his property provided the system is compliant.
In Wallonia, the Water Code (articles D.218 and following) governs sanitation. In Brussels, virtually all properties are connected. In Flanders, VLAREM sets the standards for individual treatment.
The landlord must inform the tenant of the absence of sewer connection before the lease is signed. Failure to do so may constitute a defect of consent.
Distribution of obligations
Landlord
| Obligation | Detail |
|---|---|
| Compliant system | Septic tank or micro-station meeting standards |
| Major maintenance | Replacement, structural repair |
| Compliance upgrade | If regulations evolve |
| Information | Inform the tenant of the system and its maintenance |
| Certificate | Provide the compliance certificate (if existing) |
Tenant
| Obligation | Detail |
|---|---|
| Compliant use | Do not discharge toxic products (oils, solvents) |
| Routine maintenance | Periodic emptying (every 2-4 years, cost: 150-300 EUR) |
| Reporting | Notify the landlord of any problem (odours, overflow) |
| Following instructions | Use compatible cleaning products |
Charges
Emptying the septic tank is a service charge (routine maintenance) borne by the tenant. Replacement or compliance upgrade is borne by the landlord.
For the rules on charge allocation, see our guide on service charges.
Bringing the system into compliance
When is it non-compliant
- Septic tank over 20 years old without maintenance
- Direct discharge into a watercourse (prohibited)
- Insufficient capacity for the number of occupants
- Persistent odours or frequent overflows
Compliance works
| Solution | Cost | Lifespan |
|---|---|---|
| New septic tank | 3,000-5,000 EUR | 20-30 years |
| Micro-treatment station | 5,000-10,000 EUR | 15-25 years |
| Sand filter (phytopurification) | 4,000-8,000 EUR | 15-20 years |
Available grants
In Wallonia, the SPGE (Public Water Management Company) grants individual sanitation premiums:
- Septic tank: up to 2,000 EUR
- Approved treatment system: up to 6,000 EUR
Conditions vary according to the zone and the type of system. Contact your municipality for details.
See our guide on works and maintenance in rentals.
Specific lease clauses
The lease for a property not connected to the sewer system must mention:
- The type of system: septic tank, micro-station, sand filter
- The date of last emptying and recommended frequency
- The cost allocation: emptying (tenant) vs replacement (landlord)
- Usage instructions: prohibited products, maximum volumes
- The contact details of the emptying provider
Example clause
“The property is equipped with a septic tank with a capacity of 3,000 litres. The tenant undertakes to have the tank emptied every 3 years by an approved professional, at their expense. Toxic products, solvents and used oils are prohibited in the drains.”
To create a lease with these clauses, use our online lease generator. For other cases, see our case studies.