Old Buildings and AREI Part 8: Special Rules for Existing Installations

Not every electrical installation in Belgium needs to comply with the latest AREI/RGIE regulations. For older buildings, Part 8 (Partie 8) provides a dedicated set of rules that tolerates certain deviations from the current standard — as long as no immediate danger exists. This article explains when Part 8 applies, what is permitted, and where the limits lie.

What Is Part 8?

Part 8 of the AREI (Algemeen Reglement op de Elektrische Installaties / Règlement Général sur les Installations Électriques) is a special regulation for existing installations that were constructed and approved before the current AREI came into force.

The basic principle: as long as an installation functions safely and poses no immediate danger, it does not need to be fully brought up to the latest standards — even if it does not meet all current requirements.

Important: Part 8 is not a free pass. It clearly defines which deviations are tolerated and which are not.

When Does Part 8 Apply?

Part 8 applies to installations that meet one of the following conditions:

Condition 1: Installation Before 01.10.1981

Installations constructed before 1 October 1981 (the date the original AREI came into force) fall under Part 8 by default.

Condition 2: Approved Under the Old AREI

Installations that were approved under a previous version of the AREI and have not been substantially modified since the last approval.

What Counts as a "Substantial Modification"?

• Adding new circuits
• Expanding the distribution board
• Modifying the metering installation
• Extensive rewiring

Note: Small changes such as replacing a socket outlet or switch do NOT count as a substantial modification.

What Is Permitted Under Part 8? (Tolerated Deviations)

The following points deviate from the current AREI but are tolerated under Part 8 during inspection:

1. Old Cable Types

2. Residual Current Devices (RCD)

Note: Even under Part 8, a 300 mA main RCD is recommended and often required by the grid operator when a new meter is installed.

3. Socket Outlets Without Earth Contact

Old socket outlets (type C, without earth pin) are tolerated under Part 8, provided that:

• No Class I appliances (with metal housing) are connected.
• The socket is not in the bathroom or in a damp location.
• The circuit is otherwise intact.

4. No SPD (Surge Protection)

The current AREI requires a Type 2 SPD (Surge Protection Device) for new installations. Under Part 8, this is not required.

5. Old Distribution Technology

• Fuses instead of MCBs are permitted.
• Screw-type fuses (Diazed) are tolerated.
• Missing labelling is noted as a deficiency but does not cause a failure.

6. No Fire Reaction Classification of Cables

Cables without CPR classification (installed before 2017) are tolerated, as the CPR regulation only applies from July 2017 for new installations.

What Is NOT Permitted (Even Under Part 8)?

Certain conditions are never tolerated, regardless of the installation's age:

Absolutely Impermissible:

Safety-Related Minimum Requirements:

Even under Part 8, the following must be ensured:

• Adequate cross-section for the actual load (no overloaded 0.75 mm² cable).
• Functioning fuses (no "bridged" fuses).
• Earthing of the main board (connection to earth electrode).
• Accessibility of the distribution board.

Periodic Inspection

Every 25 Years Mandatory

Existing installations under Part 8 must undergo a periodic inspection every 25 years by an approved control body.

On Change of Ownership

When selling a property, a valid inspection certificate (less than 25 years old) is mandatory. If none exists, an inspection must be carried out before the sale.

18-month deadline (Art. 8.4.2.2): When purchasing a property with a negative inspection report, the buyer has 18 months from the purchase date to remedy the defects and have a re-inspection carried out.

What Is Checked During the Periodic Inspection?

Note: Even under Part 8, a single-line diagram and a situation plan must be available — even if they need to be created retrospectively.

The Contamination Rule for Partial Renovations

A particularly important aspect for old buildings: the so-called contamination rule.

How Does It Work?

When you substantially modify part of your installation (e.g., adding new circuits):

1. The new part must fully comply with the current AREI.
2. The existing part continues to be assessed under Part 8.
3. BUT: If the new part "contaminates" the existing part (e.g., new cables in the same distribution board), the inspector may decide that the entire board must comply with the current AREI.

Practical Consequences:

• Plan renovations so that new and old parts are clearly separated.
• Ideally, use a separate sub-board for new circuits.
• Document precisely what is old and what is new.

Recommendation: Gradual Modernisation

Even though Part 8 tolerates deviations, gradual modernisation is recommended:

Priority 1 (Safety-Critical)

• Retrofit a 300 mA main RCD (if not present)
• Replace damaged cables
• Fix loose connections
• Check and improve earthing if necessary

Priority 2 (Recommended)

• 30 mA group RCDs for bathroom and kitchen
• Replace old fuses with MCBs
• Retrofit SPD Type 2

Priority 3 (Comfort + Future-Proofing)

• Modernise the board (more rows, labelling)
• Retrofit socket outlets with earth
• Preparation for EV charger / PV system

Cost Orientation

Summary

Related Articles

• Electrical Inspection in Belgium: What Is Checked?
• What Changes with the AREI 2026?
• Preflex vs. Open Wiring
• Distribution Board Planning

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