Basic knowledge

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On this page, you will find to the point summarizations for some of the most important AREI regulations for domestic electrical wirings fitted post October 1st, 1981. This information will enable you to start designing in accordance with the AREI legislation. Nevertheless, it is recommended to have your schematics reviewed and actual installation fitted by a certified electrician. Because the AREI is subjected to constant updates be sure to always consult the most recent publication.

In order to avoid confusion: the AREI is covered by the Belgian legislation and thus only applicable for electrical installations on Belgian territory. For The Netherlands please consult NEN 1010, for France NF C15-100 and for UK BS7671.
When should an official investigation of conformance be conducted? Which documents should I be able to present...
Which cable sections are required for use as earth conductor? Where to place the measurement bar...
How to connect the electricity meter to the distribution board? Which kind of main circuit breaker should I install...
Also known as residual-current circuit breaker. Different sensitivities are required depending on several conditions...
Depending on the load and installation method different cable sizes and types of wires need to be used, find the correct one here...
An overview of cable cross sections and the required nominal current for the circuit breakers and fuses...
Is there a restriction of the amount of lights per circuit? How should the lighting circuit be protected? What cable sections need to be applied...
The amount of electrical outlets is limited by the AREI... What is a mixed circuit? Are there requirements for outlet placement...
Certain appliances require a dedicated circuit. Some examples are washing machines, dryers, dishwashers...
Should double pole switches be used in the bathroom? Is it the neutral or line wire that should be interrupted? How to switch outdoor lighting...
Which are the different zones in a bathroom and what is allowed by the AREI for each zone...

AREI paperwork

The AREI defines a set of regulations to which electrical installations on Belgian territory should comply. These regulations are in effect since 1 October 1981. Because the AREI is subjected to updates and changes it is recommended to consult only the most recent publication.

  • Electrical installations that are in contravention of the AREI are not allowed to be put in service
  • An investigation of conformity by an official certification body is required for:
    • New electrical installations
    • Major expansions or changes
    • Increase of connection capacity
    • Temporary connections
    • Selling a house with an installation predating October 1st, 1981
    • Recertification of compliance every 25 years
  • You are expected to present following documents:
    • Electrical diagram
    • floor plan with the location of each electrical component
  • Each circuit should be identified with a capital letter (A, B, C...) whilst each lighting point and socket must be numbered.

  • All documents must be offered in triplicate and should contain following additional information:
    • Address of the electrical installation
    • Name of the owner
    • Name of the electrician and TAV-number
    • Name of the certification body
    • Signature of the electrician, the owner and the certification body
    • Date
  • Article 278 of the AREI contains exceptions applicable to homes predating 1 October 1981.


A measurement bar must be fitted between the earth conductor, arriving from the earth electrode and the main earth terminal. The measurement bar must be accessible during the investigation of conformity.

Keep in mind following cross-sections:

Conductor Minimal cross-section
Bare earth conductor 25mm²
Insulated earth conductor 16mm²
Main protective conductors 6mm²
Main bonding conductors 6mm²
Bare supplemental bonding conductors 4mm²
Insulated supplemental bonding conductors 2.5mm²
Protective conductors for sockets 2.5 mm²
Protective conductors for lighting 1.5 mm²

The earth conductor connects the actual earth electrode with the main earth terminal. Usually the main earth terminal contains a measurement bar that allows disconnection from the main protective conductor for the purpose of corrected earth resistance measurement.

Bonding (or the bringing of external conductive parts to the same electrical potential) must be established with a conductor connected directly between the main earth terminal and the external conductive parts (like water and gas piping) - Be sure to consult the AREI for a list of conductive parts subjected to bonding. Note that these bonding connections are usually not mentioned on the electrical diagram.

Protective conductors must be color coded yellow/green and may not be used for any other purpose.

The distribution board or consumer unit

The main distribution board must be equipped with a main breaker in accordance with the connection capacity of the installation but sized minimal 40A.

Confirm with your local distribution network operator which kind of meter tails to prepare. For a three-phase connection this typically is a cable with 4 conductors and a cross-section of 10mm². The protective conductor is not included in this connection. For example VVB 4 x 10mm².

A commonly used cable for connecting the electricity meter with the electrical grid is an EVAVB 4 x 10mm². Please verify with your local distribution network operator.

The main distribution board must be positioned within normal reach at approximately 1.5m meter height.

The residual-current circuit breaker

  • The main residual-current circuit breaker must connected as the first element in the distribution board

Earth electrode resistance lower than 30 Ohms:

  • The main residual-current circuit has a sensitivity of 300mA and a rated current of minimal 40A
  • Supplemental residual-current devices with a sensitivity not exceeding 30mA must be applied to protect following circuits:
  1. Bathrooms
  2. Washing machines
  3. Dishwashers
  4. Tumble dryers
  • Outlets installed in zone 2 of a bathroom must be protected by an residual-current circuit breaker with a sensitivity of 10mA
  • Additional residual-current circuit breakers cannot be of the same type as the main residual-current circuit breaker
  • Floor heating requires an additional residual-current circuit breaker with a sensitivity of 30mA or 100mA
  • It is allowed to connect multiple residual-current circuit breakers in both serial and parallel

Earth electrode resistance between 30 Ohms and 100 Ohm:

  • All requirements for earth electrode resistance lower than 30mA are applicable
  • An additional residual-current device with a sensitivity of 30mA is required for lighting circuits
  • An additional residual-current device with a sensitivity of 30mA is required per circuit or circuit consisting out of maximal 16 single or multiple outlets
  • Electric stoves, freezers and refrigerates are allowed to be protected by an residual-current device with a sensitivity of 100mA

Earth electrode resistance higher than 100 Ohm:

  • The electrical installation does not comply with the AREI and will not be connected to the public grid


Cable sizing:

Usage Minimal cross-section
Lighting 1.5mm²
Sockets 2.5mm²
Mixed circuits: Lighting and sockets 2.5mm²
Control or signalization circuits 0.5mm²
Electric stove, oven, washing machine,...3-phase 4mm²
Electric stove, oven, washing machine,...1-phase 6mm²

Circuits for controlling or signalization purposes must be protected by circuit breakers with a nominal current of 4A or by fuses with a nominal current of 2A
A cross-section of 2.5mm² is allowed under following conditions:

  • The load does not exceed the current limit for the cable cross-section
  • The cable runs fitted on the wall or runs aerial
  • The circuit is made up of isolated wires fitted in a conduit with a minimal diameter of 25mm
  • An empty conduit to the same location was accommodated

Allowed installation methods:

Installation method VOB
PVC or metallic conduit yes yes yes yes
Nonmetallic and nonflammable plinths yes yes yes yes
Aerial or overhead no yes yes yes
Recessed in the wall without conduit no yes yes no
Wall recessed conduits should run only vertical or horizontal.

Protection devices

The maximal nominal current of a protection device is determined by the used cable sizing:

Cross-section 1.5mm² 2.5mm² 4mm² 6mm² 10mm² 16mm² 25mm² 35mm²
Fuse 10A 16A 20A 32A 50A 63A 80A 100A
Circuit breaker 16A 20A 25A 40A 63A 80A 100A 125A

Lighting circuits

  • Circuit breaker with nominal current of 16A
  • Cabele cross-section minimal 1.5mm²
  • The AREI requires minimal 2 independent lighting circuits for a domestic installation
  • There is no limit on the amount of lights in a circuit given the total load does not exceed the current limit for the cable cross-section
  • A single light fixture with multiple light sources, for example a chandelier or a group of ceiling spots lights controlled via the same switch count as a single light

Socket outlets and mixed circuits

  • Circuit with only socket outlets: circuit breaker with nominal current of 20A
  • Mixed circuits (lighting and socket outlets): circuit breaker with nominal current of 16A
  • Cross-section minimal 2.5mm²
  • A maximum of 8 single or multiple socket outlets (under the face plate) per circuit
  • In a combined circuit a lighting point counts as an outlet and a cable cross-section of minimal 2.5mm² must be used
  • Sockets must be located at minimal 25cm from finished floor, 15cm is allowed in locations with no risk of humidity
  • Socket outlets with integrated safety shutter must be used, exceptions exist for sockets on consumer units and for fixed appliances
  • Socket outlets must have an earth pin wired to a protective conductor

Dedicated circuits

The appliances listed below require their own dedicated electrical circuit:

  • Washing machines
  • Tumble dryers
  • Dishwashers
  • Electric ovens
  • Electric stoves
  • Central heating


Light switches:

  • Single pole switches are allowed up to 16A, single phase
  • Impulse switches and dimmers (e.g.. home control) are allowed up to 16A, single phase
  • The live wire must be interrupted by the switch in a single phase circuit
  • Single pole switches are allowed in bathrooms, double pole is recommended
  • Single pole switches are allowed for outdoor lighting, double pole is recommended
Double pole switches are mandatory in single phase >16A circuits


All bathroom circuits require protection by a residual-current device with a sensitivity not exceeding 30mA.

The AREI distinguishes following zones in a bathroom:

  • Zone 0: The internal zone of the bathtub or shower tub
  • Zone 1: The zone above the bathtub to a height of 2.25m. A circle with a radius of 0,60m has to be used in case the shower has no tub
  • Zone 2: The zone outside zone 1 vertical limited to 0,60m from zone 1 (same height as zone 1)
  • Zone 3: The zone outside zone 1 vertical limited to 2,40m from zone 2 (same height as zone 2)
Zone Allowed Protection
0 SELV 12V/6V IP-x7/00
1 Sanitary water heater IP-x4
SELV limited to 12V AC, 30V DC IP-x4
SELV limited to 6V AC, 20V DC IP-x0
1A Power supply for whirlpool, jacuzzi baths IP-x4/xx
2 SELV limited to 25V/12V AC IP-x4/00
Lighting with switch, mimimum 1.6m above floor IP-x4
Fixed electric fan heater (class 2) IP-x4
Socket outlet via isolating transformer (max. 100W) IP-xx
Socket outlet via residual-current device of 10mA IP-xx
Sanitary water heater IP-x4
3 Miscellanious IP-x1
SELV limited to 12V AC, 30V DC IP-00
SELV: Seperate Extra-Low Voltage, AC: Alternating Current, DC: Direct Current, IP: International Protection Rating or Ingress Protection
The first x indicates the level of protection (0-6) that the enclosure provides against access to hazardous parts and the ingress of solid foreign objects
The second digit indicates the level of protection (0-9) that the enclosure provides against harmful ingress of water:
  • 0 = Not protected
  • 1 = Vertically falling drops shall have no harmful effect
  • 4 = Water splashing (10l/min) from any direction shall have no harmful effect
  • 7 = Ingress of water not be possible when the enclosure is immersed in water (30min at 1m)
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