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Legal situation in Brussels

The Earth's heat is a renewable source of energy. Geothermal systems can help reduce both our energy use and our impact on the environment. However, they can also pose a risk for the environment, for instance if they were poorly designed or installed. This is why authorisation is required to operate certain types of geothermal systems. The table on this page presents the authorisations required for the various types of geothermal systems, based on current legislation in the Brussels-Capital region. Advice from an architect or an engineering firm with experience in designing geothermal systems can be helpful in order to navigate the administrative procedures involved.

Geothermics is covered by two types of legislation: environmental protection and urban planning.

Geothermics and the environment

In the Brussels-Capital region, there are currently no specific laws that govern geothermal systems. However, such systems could fall under two laws:

  • Geothermal systems of any depth almost always consist in equipment that is covered by the ordinance of June 5, 1997 on environmental permits; as such, they require either notifying the authorities or applying for an environmental permit. In this case, the environmental permit sets the criteria that must be met to install and operate the geothermal system. Most geothermal systems that exist in Brussels are shallow systems with open or closed systems.
  • Open geothermal systems of any depth are also subject to a different law, as they are groundwater collection systems. As such, they require an authorisation to collect groundwater, in accordance with royal decree of April 21, 1976, on groundwater usage. Most open geothermal systems that exist in Brussels are shallow ones.

Closed geothermal systems

The type of permit required depends on the system's technical characteristics. The following components are regulated:

  • Heat pump: may fall under category 132 of the list of regulated equipment
  • Recirculation pump (an electric pump that circulates the heat transfer fluid through the loops): may fall under category 55 of the list of regulated equipment.
Heat pump Recirculation pump Type of authorisation Type of project
Rated electrical power of the compressor ≤ 10 kWh
and/or
Amount of heat transfer fluid in the heat pump < 3 kilograms of ozone-depleting substances
Rated power
< 100 kVA
No authorisation required Most geothermal systems for single-family homes fall under this category.
Rated electrical power of the compressor > 10 kWh but < 100 kWh
and/or
Amount of heat transfer fluid in the heat pump ≥ 3 kilograms of ozone-depleting substances
Rated power
≥ 100 kVA but ≤ 250 kVA
Mandatory notification (class 3) Most geothermal systems for apartment buildings and office buildings fall under this category
Rated electrical power of the compressor ≥ 100 kW Rated power
> 250 kVA but ≤ 1,000 kVA
Class 2 environmental permit Large geothermal systems with a high number of loops (generally 100+ loops) fall under this category.
To find out how to submit a notification or how to apply for an environmental permit, we suggest you visit the Environment Brussels website or click on the following link:
http://www.environnement.brussels/le-permis-denvironnement/le-guide-administratif

To find out what information and documentation must be included with your notification or application for an environmental permit, please see the following document 
List for closed geothermal systems
Download PDF (pdf 276Ko)

Open geothermal systems

The type of permit required also depends on the system's technical characteristics. The following components are regulated:

  • Heat pump: may fall under category 132 of the list of regulated equipment
  • Recirculation pump (an electric pump that collects water from and re-injects it into the aquifer): may fall under category 55 of the list of regulated equipment
  • Underground hydrant: always falls under category 62 of the list of regulated equipment.

As underwater hydrants always require an environmental permit, open geothermal systems also always require an environmental permit. The category of permit required depends on the rate at which water is pumped from (and re-injected into) the aquifer.

Underground hydrant Type of authorisation
Pumping rate ≤ 96 m³/day Class 2 environmental permit
Pumping rate between 96 m³/day and 20,000 m³/day Class 1B environmental permit
To find out how to apply for an environmental permit, we suggest you visit the Environment Brussels website or click on the following link
http://www.environnement.brussels/le-permis-denvironnement/le-guide-administratif

To find out what information and documentation must be included with your application for an environmental permit (class 1B or class 2), please see the following documents:
List for open geothermal systems 
Download PDF (226Ko)

If you are planning on installing an open geothermal system, you must also submit an application for an underground hydrant permit following the procedure below:

Underground hydrant Type of authorisation
Pumping rate ≤ 96 m³/day Class I authorisation
Pumping rate > 96 m³/day Class II authorisation

Please note: Drilling a well intended for a pumping test does not require a permit, provided the test lasts no more than 2 months and the testing well is not converted into a permanent hydrant.

Applications for underground hydrant permits must be submitted to Environment Brussels using the forms available on the following page: 
http://www.environnement.brussels/thematiques/eau/leau-bruxelles/eaux-souterraines/formulaires-relatifs-aux-demandes-dautorisation-de.
A list of required documents is provided in the forms.

It should be noted that relevant laws are under review, and that the dual permit system currently in force for open geothermal systems may be simplified. A specific law regulating geothermal systems (both open and closed) will soon enter into force.

Geothermics and urban planning

The Brussels code of town and country planning (known as CoBAT) requires a planning permit to build or install permanent equipment on a given piece of land (article 98, §1.1).

This means that installing a geothermal system also requires a planning permit.

To find out how to apply for a planning permit and what documents are required, we suggest you visit the Brussels' town planning website or click on the following link:
http://urbanisme.irisnet.be/lepermisdurbanisme/la-demande-de-permis

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