Are old fuse boxes illegal? Here’s why you need to change yours
I live in a house built in the 1950’s so not an old house compared to some but certainly not new, I have been renovating this property for a few years and never really had to deal with the electrics until now because I am planning for a new kitchen and now we need some rewiring and a new fuse box in order to meet regulations.
This got me wondering if the old unit, which is made from metal and bakelite and still has fuse wire, is up to code and if not is my old fusebox illegal? So I did a little digging around and here’s what I found out:
Old fuse boxes are not illegal, not being up to current standards such as BS 7671: 2008 or NFPA 70, means that they won’t have the latest RCD protection, which could save your life. Fuseboxes with old fuse wire should be upgraded to a modern unit, this must be done by a qualified electrician and will cost $400 – $700.
Generally, an old-style fusebox is not a legal issue but getting rid of the old unit and replacing it with a new consumer panel with RCD protection is a good idea and here’s why:
Oldstyle fuse box Vs New consumer panel
It’s fairly easy to tell if your property is fitted with an old fusebox or a new consumer panel, firstly they will look completely different.
A new up to date Consumer unit will look like the image below a plain white of grey outer cabinet with a red main isolation switch, at least two RCD‘s to protect the main circuits and black MCBs for each circuit, all of which will be fitted in a row behind the front panel,

Whereas an old-style fuse box will look like the image below with a metal cabinet and door, a single breaker switch, and large ceramic fuses that have the fuse wire across the back.
Old Style Fuseboxes
Millions of homes will have been built before current legislation was brought in to law, this means that most of them won’t meet the current standards set by the authorities.
But they are not illegal unless you intend to rent the property, it would be a huge job to check and change every single one, so authorities rely on local contractors to keep up to date with current requirements and advise homeowners when things need to be changed.
Fuseboxes typically consist of the following items:
- Main cabinet
- Door
- Power supply
- Main breaker
- Circuit breakers
- Buzz bar
- Earth connection.
The old-style cabinets are usually made from light grade metal and the circuit breakers are made from an electrical insulator such as ceramics or bakelite, these hold the metal pins connectors which are pushed into the panel board.
The metal pins are in turn connected with fuse wire of a particular rating, typically 5 amp for a lighting circuit or 30 amp for a cooker for example.
When the circuit overloads the fuse wire should overheat and burn out quickly thus breaking the circuit,
To reset the circuit the fuse wire must be replaced. An old fusebox which has been installed and working for many years will continue to do so if looked after.
There are several issues with this old-style fusebox,
there are lots of potential issues with old-style fuse boxes the man ones are listed below:
- The circuit will not fail as quickly as a new RCD unit
- The fuse wire gets hot which could lead to a risk of fire
- The power must be shut off before replacing the fuse
- It’s too easy to use the wrong fuse wire
- You need several different reels of fuse wire
- Rewiring a fuse in the dark is not great fun
There are more hassles to having an old-style fuse box, but generally, they are considered less safe than the latest units.
For example, putting 5 amp fuse wire into a 30 amp circuit will blow the circuit every time you turn on the oven, which is going to be annoying and become a headache.
However, if a 30 amp fuse wire is put into a 5 amp circuit, then appliances are likely to be damaged or worse, the wiring could be overloaded which will get hot and could cause a fire

Latest electrical regulations
Electrical codes and regulations vary for different countries but are set up to ensure one thing the improved safety of the end-user.
Codes are constantly revised and re-written so that an installation that was within guidelines 10 years ago may well be safe but may not be up to the latest standards.
Regulations are updated to make the most of new technology and improvements in the design and manufacture of safety devices used in new fuseboxes like Miniature circuit breakers also know as MCB’s and residual current devices also called RCD for short.
BS 7671: 2008, for example, is an update to the previous standard, and is used by electrical contractors in the UK and NFPA 70 in the US as guidance and best practice for new installations and updates.
You can find out more about US codes at the NFPA website using the link below:
National Fire Protection Association
For more information on BS electrical standards check out the BSI website using our link:
Changes and updates to regulations include the materials of manufacture, for example, previously consumer panels could be made from heavy-duty plastic, and new legislation states that they should be constructed from metal.
The Legal Question
From a legal standpoint, although the plastic versions are not in line with current regulation, they are safe they this means they do not need to be changed unless they are found to be faulty, but there may be reasons why old-style units should be updated.
When old fuseboxes are still being used most local contractors will and should advise they be replaced with the latest standard to ensure the safety of the occupiers.
They can refuse to carry out work on circuits that include old-style fuse boxes as it would be potentially dangerous to carry out any work whilst this type of outdated safety device is installed
Fuseboxes in Rental properties
There are more stringent standards for rental properties, which are intended to provide the safety of the tenants and the peace of mind for the landlord.
Regular electrical inspections are required for properties that are rented. This is to prove that the property is safe for tenants to live in.
In the UK an electrical inspection should be carried out every 5 years, this will include inspection of the electrical appliances, the wiring, and the fusebox and safety devices.
If a circuit board or fusebox does not meet the current regulation is must be replaced with a consumer unit that does, so that a certificate of compliance can be issued.
Cost to replace a fusebox
Replacing a fusebox is a job for a qualified electrician as they must be trained to carry out the work and registered to complete the self-certification required.
When looking for a contractor it is always a good idea to get at least 3 different quotes to compare and ask friends or family for recommendations for people they have used before.
An example of the cost to replace an old fuse box in a 2 bedroom home will take 3 hours and cost between $500 (£350) – $650 (£450), (Please note that these prices are correct at the time of writing)
Larger or older properties may cost up to $800 (£560) due to the length of time required to complete the work.
These costs should include the parts required such as the new consumer unit, RCD & MCBs, the installation, and certification.
Should you change your Fusebox?
If your property is less than 25 years old or has been fitted with a new consumer panel that uses RCD & MCB technology then upgrading to the latest standard is not required unless you have faulty wiring.
Any older than this and it’s probably worth upgrading to the latest standard and spending less than $700 (£500) to stay safe and potentially save your life is a bargain.
Contacting your local electrical installer and having your electrical circuits checked regularly is also a good idea not only will this mean you have peace of mind that your house is safe and up to date with the latest regulations, but you can also identify and fix any issues before they become a problem.

This article was written by: Richard Quinton – The DIY Help Desk Owner, Engineer & technical specialist.
Richard is one of the key partners in The DIY Help Desk team. He is a qualified Engineer, writer, and publisher, educated to Master’s level. He is a keen advocate of DIY and home improvements.
Richard enjoys helping others to learn new skills and reach their goals and believes that passing his knowledge and experience on through his writing is an effective way to positively impact the lifestyles and well-being of others on a larger scale.