Distribution Board Upgrades – Cost, How Often?, Types

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Distribution Board Upgrades

Electricity has become such an important part of our lives that it is difficult to imagine what life would be like without it.

From powering the lights in our homes to heavy machinery in industrial properties, it all depends on electricity and its constant supply.

Due to modern technology, it has become so common that we have started to take it for granted, oftentimes overlooking the safety measures that must be taken when using it.

Electricity is one of the most common causes of fires in domestic and commercial properties, which is why the electric wiring and installations need to be properly tested and maintained on a regular basis to ensure they are working properly.

A few basic components of an electrical system include the wiring, circuits, electric panels, circuit breakers, switchboards, light fixtures, consumer units, and distribution boards.

Just like you need to replace and upgrade the wiring and light fixtures when they show signs of damage, you also need to upgrade your distribution board so that your property keeps getting an uninterrupted and safe supply of electricity to power it.

Read on to find out what a distribution board is, its different types, why you need to upgrade it and how often, and the costs associated with upgrading an old distribution board with a new one:


A distribution board, also called a distribution panel, breaker panel, or electrical panel is an integral part of a property’s electrical system responsible for splitting an incoming electrical power supply into several secondary or subsidiary circuits, most of which are protected with a fuse or breaker.

In the UK, distribution boards are also often referred to as consumer units in domestic properties, although they are not completely interchangeable (more on this in a bit).

Normally, you will find that all the fuses, breakers, and circuit protection devices are held within the same single enclosure, however, the distribution boards are often only semi-enclosed or kept open.

Since most places rely on these devices to divide and route a single source of electric supply to multiple subsidiary circuits around the property, most of them will be enclosed for safety.

Whether it is an outdoor distribution board, a commercial one, or a dedicated one used for public venues, all distribution boards are essentially used for the same purpose: taking an incoming electrical supply, splitting it in multiple ways, and rerouting it into several secondary circuits.

This allows for more precise control over the electric supply to various areas of the property, in addition to isolating and shutting down specific parts of the system without completely killing off the main power supply.

Distribution boards also offer additional safety features in the form of fuses, breakers, and RCDs (residual current devices) that ensure safe use of the power supply.

Also, since each subsidiary circuit has an individual safety feature, the entire system is better protected against issues such as power surges, overloads, short circuits, and other electrical safety hazards.


Most people are often confused and unclear about the difference between distribution boards and consumer units, and whether there is any.

The fact that distribution boards are oftentimes referred to as consumer units further increase the confusion.

While in practice, the difference between the two is only with reference to certain use cases, in reality, a consumer unit is a type of distribution board.

What this means is that while all consumer units are distribution boards, all distribution boards are not consumer units.

Consumer units are generally found in buildings and are recognisable by their metal or plastic enclosure containing several fuses and breakers.

That being said, a consumer unit is simply a specific type of distribution board that is used in typical residential and commercial settings and is approved as a safe electric panel design.


There are 3 main types of consumer unit distribution panels: main switch consumer units, dual RCD consumer units, and high-integrity consumer units.

Main switch consumer units

One of the safest and most robust devices for incoming electricity supply, main switch consumer units are a popular choice for single-storey houses and small flats.

All the circuits are completely separated and the units have a single main switch through which all the subsidiary circuits can be switched off.

Dual RCD consumer units

Although a step down in terms of their protective capacity, dual RCD consumer units are suitable for certain uses and provide robust protection against overheating and electrical fires.

Consisting of two sets of circuits protected by RCD breakers, these units offer dual functionality in the event of one of them not being operational.

High-integrity consumer units

More commonly found in larger buildings with several secondary circuits branching off of the main incoming electric supply, high-integrity consumer units combine the functionality of dual RCD protection with additional RCBOs (residual current breaker with overcurrent protection).

In addition to the aforementioned consumer unit distribution panels, there are various other types of distribution boards and sub-distribution boards you can commonly find installed in domestic and commercial properties:

Type A and Type B distribution boards

Type A and type B distribution boards offer different compatibility with certain overcurrent protective devices (OCPDs) and various configurations of busbars.

When selecting one for installation in commercial or industrial properties, you will have to factor in certain location-specific codes and standards and choose the right one that is compliant with them.

Other determining factors include general operating conditions, environmental factors, and accessibility requirements.

Sub-distribution or sub-boards

A sub-distribution board is essentially a smaller distribution board acting as a subsidiary to a larger one, enabling greater control and isolation of several smaller circuits and breakers.

An RCD incomer consumer unit is a common example of a sub-board, that doesn’t have a main switch onboard and will usually be located on a larger distribution board that the sub-distribution board is attached to.


A distribution board, like all other electrical installations on your property, will deteriorate over time and may even become obsolete.

Damaged or outdated electrical components pose a serious safety hazard to the property that they are installed in and the people residing in it.

Things have changed a great deal over the years, with reference to advancements in technology, often making old distribution boards no longer suitable for todays residential, commercial, and industrial properties.

The old versions are simply not designed to cope with today’s needs and the number of electrical devices that depend on them, which is why, as time goes on and more installations are added to the electrical system, the old distribution boards may overload and pose some serious problems.

Here are all the reasons why you might need to upgrade your distribution board:

Improved electrical safety

An outdated or faulty distribution board could lead to some serious damage which is why it is best to have it upgraded by a professional ASAP.

Some older distribution boards do not have certain essential components, such as an RCD (residual current device) that breaks the electrical current during a power surge, which may lead to a severe risk of electrical fires and a potential loss of life and property.

In addition to that, some older models are made of plastic, while newer ones are metal or metal-clad ones since they are much safer and prevent fires from spreading.

Compliance with the law

The distribution board on your property must meet Part P of the building regulations and must be safe and compliant with the laws governing electrical systems in the UK.

Failure to meet these regulations may not only put you, your property, and others at risk but also land you in some serious trouble with the authorities.

The best way to make sure that your installations are compliant with the law is to have a professional electrician check them out during periodic tests and inspections.

During these maintenance checks, if your distribution board turns out to be faulty or outdated, you must upgrade it to a new one in order to stay compliant with the law.

Increased energy efficiency

A properly working distribution board will not only keep you safe and compliant with the law but also increase your property’s energy efficiency.

It helps keep all power surges and overloads under control and don’t let them adversely affect your electrical appliances.

A simple upgrade will not only help you conserve valuable energy but also save you money on utility bills and malfunctioning appliances caused by an inefficient distribution board.

Peace of mind

In being compliant with the electrical regulations and improving your property’s safety by upgrading your distribution board, the biggest benefit you enjoy is peace of mind.

Knowing that you, your property, and everyone in it is safe from electrical risks due to outdated electrical components eases your conscience knowing that you played your part in ensuring it.


The best way to determine whether you need to upgrade your distribution board is to check whether it is working fault-free and is compliant with the law.

How can you do that, though? Through professional checks and inspections of course.

Periodic checks and inspections refer to having your electrical wiring, installations, and components checked by a professional and certified electrician who can give you a detailed report about each component and whether it is safe to use or not.

It is recommended in the wiring regulations BS 7671 that a domestic property must be regularly inspected and tested after every 5 to 10 years or if you are buying/selling the property.

For businesses and commercial properties, it is a requirement under The Electricity of Work Act 1989 to carry out an Electrical Installation Condition Report (EICR) at regular intervals, ranging from 3 to 5 years.

You may, of course, have the tests and inspections done more frequently as well, depending on your use and the health of your electrical system.

A few obvious signs that indicate your distribution board is due for an upgrade include:

  • The age of your home: if your home was constructed several years back and you are unsure when the distribution board was installed, it is always best to have an electrician take a look.
  • Old distribution board: some old distribution boards have become obsolete and are no longer compliant with the wiring regulations. Therefore, you must have them upgraded to newer models that are much safer and efficient.
  • Flickering lights: a single flickering light could simply mean that the lightbulb is loose or needs to be changed. However, if it happens with more than one light bulb, it may indicate issues with the distribution board.
  • Appliances short-circuiting: if your appliances and machinery are constantly short-circuiting and tripping, it may be caused by an overloaded distribution board.
  • Buzzing noises: if you hear buzzing noises coming out of the distribution board or other installations, it is best to have a professional electrician take a look ASAP.
  • Sparks and shocks: if you notice sparks and experience shocks every time you plug in your appliances, it can be a sign that the distribution board isn’t working as effectively and needs to be upgraded.

While these are some of the most common tell-tale signs of there being an issue with your distribution board, this list isn’t exhaustive and may include many other issues, such as discolouration, smoke, and the circuit breaker tripping constantly.

Therefore, it is best to speak to a professional electrician who can take an in-depth look at all your installations, including the distribution board, and let you know if any changes or upgrades need to be done.


The process of upgrading a distribution board is typically scheduled for 1 to 2 days and is carried out by a certified electrician.

It usually requires installing a residual current device (RCD) that protects electrical circuits, prevents electric shocks, and minimised the risk of fires due to faulty or damaged electrics.

The upgrade may also include the installation of miniature circuit breakers (MCBs) that provide immediate disconnection in case of an electric fault.

The steps involved in a distribution board upgrade include:

  • Determining the current condition of the unit by undertaking a detailed inspection.
  • Cutting off the power supply to make it safe to remove the existing installation.
  • Installing the new distribution board.
  • Checking the connections throughout the property to ensure they are working properly.
  • Re-energising the distribution board and carrying out a final test.
  • Issuing a certificate of compliance.


The total cost of a distribution board upgrade depends on several factors such as:

  • The size,
  • The type, and
  • The capacity of the distribution board, in addition to
  • The amount of cabling required,
  • Whether your property needs to be rewired, and
  • The labour costs for the upgrade.

Keeping all these factors in mind, the average cost of a distribution board upgrade should be around:

  • £300 to £400 for a 6-circuit distribution board,
  • £400 to £500 for a 10-circuit distribution board, and
  • £500 to £600 for a 12-circuit distribution box.

To get a better idea of the exact costs depending on your requirements, it is best to speak to a professional electrician who will assess your needs and provide you with a detailed quote.


We have been providing electrical services to residential, commercial, and industrial properties for over 40 years and are specialists in all aspects of electrical installations, maintenance, and testing.

We have experienced and fully qualified electrical engineers on hand to deliver a professional and high-quality service and are NICEIC registered following the current wiring regulations.

If you have unplanned issues within your home or business, we can provide a call out service to rectify and solve any problems – ranging from circuits tripping, loss of power, broken items that need repairing, to distribution board and consumer unit upgrades and much more.

Our team can generate a Visual Inspection Report (VIR) to identify anything visual that does not comply with the standards or looks unsafe, as well as a full Electrical Installation Condition Report (EICR) where we identify and test each circuit to make sure they are not deteriorating and are safe for use within the current standards and regulations set by the BS 7671.

We also provide PAT testing of appliances to make sure that any items such as kettles, computers, and microwaves are safe for use in the home and workplace.

Contact us here or call us on 0800 612 3001 to talk to our certified team of electricians and get your faulty or obsolete distribution boards upgraded right away!

Photo by Ralph (Ravi) Kayden on Unsplash