When Did Metal Consumer Units Become Law?

Metal Consumer Units became a legal requirement for new domestic electrical installations in the UK on 1 January 2016. This change came under Amendment 3 of the 17th Edition Wiring Regulations (BS 7671) to help reduce fire risk.

Background to the Change

A Consumer Unit, also known as a fuse box, is the main control centre for the electrical system in your home. It holds fuses or circuit breakers that protect each electrical circuit.

For many years, most Consumer Units were made from plastic. These units were cheap to make and looked tidy on the wall. However, over time, concerns grew about plastic Consumer Units’ safety, especially in a fire. If a connection became loose and overheated, the plastic casing could catch fire and allow flames to spread.

Electricians, fire safety experts, and industry bodies pushed for stronger safety rules. This led to changes in the wiring regulations to better protect homeowners.

Amendment 3 to the 17th Edition Wiring Regulations

In 2015, the wiring regulations in the UK were updated to include Amendment 3 to the 17th Edition of BS 7671. This update introduced a new safety rule: from 1 January 2016, all Consumer Units and similar equipment installed in homes must be made from non-combustible materials. In most cases, this means metal.

The main part of the regulation is 421.1.201, which states that Consumer Units in domestic buildings must have an enclosure made from a material that won’t catch fire. This applies to new installations and major changes to existing systems. It doesn’t mean every plastic unit already in use must be replaced immediately, but any new work needs to meet this updated standard.

This change improved safety and reduced the risk of fires linked to faulty electrical systems.

Why the Law Changed – Fire Safety Concerns

The main reason behind the switch to metal Consumer Units was fire safety. Over the years, fire services have noticed more house fires caused by faults inside plastic consumer units. One of the biggest concerns was loose cable connections, which can cause parts to overheat and catch fire.

The London Fire Brigade was one of the strongest voices calling for change. They found that fires involving plastic Consumer Units were becoming more common. Because plastic is flammable, once a fire starts inside the unit, it could quickly spread to nearby materials like wood, carpets, or plasterboard.

Switching to metal Consumer Units makes any fire that starts inside the unit more likely to stay contained. Metal doesn’t burn like plastic, giving firefighters and homeowners more time to react and reducing the chance of serious damage.

This change in the law was seen as a simple but important way to make homes across the UK safer.

What Installers and Homeowners Need to Know

Since January 2016, any new Consumer Unit fitted in a home must be made from metal or another non-combustible material. This rule applies to new builds, rewires, and major electrical upgrades. If you’re having electrical work done that involves replacing the Consumer Unit, the new one must follow the latest safety rules.

However, if your home already has a plastic Consumer Unit, you don’t have to replace it just because the law has changed — unless it’s unsafe. During an Electrical Installation Condition Report (EICR), an electrician will check the condition of your Consumer Unit. If it’s plastic but in good condition and a safe location, it’s usually marked as a C3 code, which means improvement is recommended but not urgent.

If the plastic unit is under a wooden staircase or in the only exit route of the house, it may be marked as C2, meaning it’s a potential danger and should be replaced soon.

The key thing to remember is this: you don’t need to panic if you still have a plastic Consumer Unit, but it’s worth asking a qualified Electrician to take a look if you’re unsure.

Exceptions and Practical Considerations

While the law is clear about using metal Consumer Units for new work, there are a few exceptions and things to consider.

If you only have small electrical jobs done, like adding a socket or changing a light fitting, the Electrician doesn’t need to change your Consumer Unit. The rule only applies when the unit is being replaced, or major work that affects the whole electrical system is carried out.

Another factor is location — if your existing Consumer Unit is in a high-risk spot — such as under wooden stairs or in a hallway that’s your only way out in a fire — an Electrician may advise replacing it sooner, even if you’re not having major work done.

In some cases, instead of replacing the whole unit, enclosing a plastic Consumer Unit in a metal cabinet may be possible to reduce risk. However, this depends on the setup and must be assessed by a professional.

It’s always best to get advice from a qualified Electrician, especially if planning upgrades or selling your home, as electrical safety is often part of the survey process.

Summary

Moving to metal Consumer Units in 2016 was about making homes safer. Fires caused by electrical faults can be serious, and switching from plastic to metal helps to contain any problems that start inside the unit.

If your home already has a plastic Consumer Unit, there’s no need to worry — but it’s still a good idea to have it checked, especially if you haven’t had an inspection in a while. A qualified Electrician can let you know if it’s still safe or if upgrading would be better.

If you live in the Essex area and want your Consumer unit checked, please contact us using the phone number or email below.