Ask a tradesperson


Regulations for replacing consumer unit

Hi there,
Are there any regulations I should be aware of when hiring someone to replace my old fuse box with a new consumer unit?
Any additional checks or safety inspections that would need doing?

Also, I would be grateful if anyone could guesstimate at an acceptable price range for this, either including or not including the actual unit itself.


7 Answers from MyBuilder Electricians

Best Answer

Hi Siobhan,

When undertaking a consumer unit change, the electrical contractor is required to ensure the existing wiring is safe for the change. This is because you are changing the characteristics of the existing circuits. Usually this is done by carrying out a full Electrical Installation Condition Report (E.I.C.R.) before starting the change.

The contractor also has to ensure the earthing and bonding is up to scratch, that the meter tails are the correct size and that there are adequate means of isolation between the electrical meter and the consumer unit, and if not, upgrade this.

Depending on where you are in the country, it may also be required to notify this work under Part P regulations, so ensure you get a registered electrician who can do this for you (NICEIC, Elecsa, NAPIT, Stroma etc.)

Depending on the size of your consumer unit, you should expect to pay in the region of £300-£500 to have this work done, and this would include the consumer unit itself.

Hope this helps

Brendan Mines


Answered 4th Sep 2015

Dear Siobhanb,

The best advice I can offer you is firstly always use a competent registered electrician, by this I mean a company who are registered with a governing body like NICEIC, NAPIT or ELECSA and take the time to check out there registration number is valid on line, it takes minutes to save a lot of hassle. DO NOT just trust the badge or logos on paper work there are imposters out there.

The regulations on consumer units has changed, this being that any installed should conform to meet BS7671:amendment 3 and will come into force in January 2016 although its good practice to follow with immediate effect.

The main change is from PVC consumer units to metal consumer units and the aim is to provide adequate fire protection thus in the invent of the fire the enclosure contains the fire.

Of course, if installed correctly this should never happen although unfortunately accidents happen if not installed in the correct manor and loose terminals are left within the consumer unit. So long as you use a qualified electrician then this should not be a concern.

Always make sure and be clear from the start when selecting a contractor that you will receive certification upon completion of the works. This is proof that the installation has been tested and is compliant with BS7671, not only that its just as equally important that the contractor has proof that the installation is safe when leaving the site. Be aware that when undertaking a consumer unit change there may be some underlying faults that may not of been obvious beforehand especially when adding RCD (Residual current device) on to older circuits. These faults IF ANY will require to be rectified but usually at a separate cost depending on what's involved to rectify the fault.

You should receive an Electrical Installation Certificate for the works and a further certificate issued by building control in the post after the job has completed within 30 days maximum.

In using NICEIC registered firms, you can also take advantage of there "6 year platinum promise guarantee" so you can rest assured that you are covered for the labour of your installation.

Finally, the average cost of a consumer unit upgrade is around £300.00 but you could expect to pay anywhere in the region of £250.00-£350.00 depending on what's involved I.E. mains tails may require upgrading (25mm tails 16mm earth) as may the mains earth bonding to gas and water (maybe steel in some cases) should be of 10mm and MUST be in place to ensure all pipework is at the same potential in the event of a fault.

I hope this helps and good luck with the job!

(JEM Electrical)


Answered 4th Sep 2015

The work MUST be notified to local building control under Part P of the building regulations and a full Electrical Installation Certificate (3 pages) must be issued with all the test results for the completed job. Be aware that the regulations for new consumer units change on 01/01/16 and many people are using up old stock that will not comply with the new requirements that are coming into force. Make sure you ask for a metalclad amendment 3 certified consumer unit. Also check the installers NICEIC accreditation by looking on line or phoning the NICEIC. If the installer can't show you any form of NICEIC Identity card etc, then walk away and seek other quotes.


Answered 4th Sep 2015

It has to be notified to building control, you the customer, be issued with a Electrical Installation Certificate ( both by the contractor) who will be part p registered. When I change one I usually do an Electrical Condition Report first on existing installation then when the consumer unit is fitted the faults if any, are sorted out so to prevent nuisance tripping and to ensure that the sub circuits are all in line with BS 7671 I usually give a discount on this as you have to do all the testing anyway, also to be looked at and maybe to be rectified are the size and presence of main earth and gas water and or oil etc bonding conductors. Size of meter tails. I'm not putting a price on it as it varies dependant on the work required. I usually get all the materials as I know what I am buying etc. Hope this is of some help.


Answered 4th Sep 2015

Well done Brendon Mines for mentioning the E.I.C.R., this is an essential test that should be completed before any consumer unit change.


Answered 14th Sep 2015

ensure they are registered with a competent person scheme and that they have public liability insurance and ask for a written quote and maybe ask for a reference. rough price is between £350 -£500 depending on size of new consumer unit and if the old cables have to made longer etc.


Answered 4th Sep 2015

Hi, Consumer units changes are notifiable works under the part p building regulations ,so a full test and certification would be needed to be done afterwards and local authority needed to be notified, only a registered electrician should be employed to undertake the job for you unless you want to pay twice and get the local council out to certificate the new CU . Price range £300 - £375


Answered 4th Sep 2015

Post your job to find high quality tradespeople and get free quotes

Can’t find an answer? Ask a new question

Question Categories