Extensions Question

If i have a new extention built (single storie).do i have to rewire the rest of the house to the current regs.i am getting mixed advice from people .

6 Answers

the extention would have to meet regs the rest of the house would not need to be rewired but the fuse box my need to be changed or uprated

Answered 18th Feb 2012

Jonathan Dixon Builders

Member since 2 Jul 2008

no normally advice to do it normally up grade fuse box etc and advice the rest

Answered 18th Feb 2012


Member since 31 Oct 2008

Hello. You do not have to re wire the whole house to the current building regulations. If possible the new extension will be on its own circuit on the fuse board so there is no need to even touch the original wiring. The only issues you may have is if you have an old fuse board that will need replacing to accept any new wiring and the electrical test that will follow highlighting a problem with the existing. You may get an advisory from the electrician saying your current wiring is old and to just bear that in mind.

I hope this helps you out.

Wesley Lee
W Lee Carpentry Ltd

Answered 18th Feb 2012

W Lee Carpentry Limited

Member since 28 Jul 2011

if you have the old rated fuse board then yes ,the electrician will tell you it needs upgrading to a modern consumer unit rcd unit to comply with electrical/building regs

Answered 18th Feb 2012


Member since 7 Jun 2008

The builder is responsible for the area which he has worked. If the consumer unit is not up to current regulations then this will have to be addressed but the remaining house is not the builder's reponsibility nor will it have any effect on the completion certificate

Answered 19th Feb 2012

Ambux Ltd

Member since 24 Oct 2011

Good afternoon- the short answer is no, you do not have to bring the existing wiring up to current regulations, unless it is a condition of your building regulation application.
However, with most extensions, you will probably be connecting your new wiring to the existing supply at the Consumer unit(fuse board). This will have to be of sufficient capacity ,and up to current regulations, as it forms part of the new installation,as well as the old.
Your qualified electrician will be able to advise you if this needs replacing, which is very likely, and the cost associated with this should be in the region of £350- £450, if carried out as part of the new works.
Hope this helps.

Answered 19th Feb 2012


Member since 31 Jan 2012

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