I'm currently doing a re-wire on a house. I normally fit switches and sockets at the latest regulation heights but where re-wires are concerned is this required? The reason I ask is the customer wants as little chasing as possible, and the existing switches have metal conduit in the walls but at a height greater than 120mm. I will be puting sockets at 450mm since there are very few anyway so more are needed, and in different places, but all switch locations will remain as is. I know new installs are compulsary but what about re-wires?

No it is not compulsory on rewires.

Not sure they are stated in the regs are they



For Doc M - No worse in terms of compliance than the existing...




Doc M requires all accessories in a zone between 400 & 1200 ...Where Doc M applies

-------------------------
Regards

Martyn.

Only a mediocre person is always at their best



www.electrical contractors uk.com

Thanks SK, I thought that was the case but don't you think it's a bit odd?

You renew all with new wiring and accessories similar to a new install but don't have to abide to the socket & switch height reg's. I wish things were clearer - there are so many discepancies like this regarding old and new don't you think? (There's no book for this!)

There is... It's the Building Regulations... as as Martyn said, the specific bit relating to accessory height is Part M, see here: Click Here

Yooj

See "Section O"... General Guidance... Example 2: "It must be no less easy for people..."
ie yes they can stay at the same height.........................

I had a similar job like this one a couple of years ago on an old MOD house which was all conduit in walls. It was just an internal re-modelling job with an extension, and the building inspector wanted all socket and switch heights as per Part M, extension and existing within remodelled area... I pointed out that there was no requirement in the existing bit as it is not a new build dwelling... he weren't having any of it though, and it would have been a nightmare as the walls were bomb proof. I got straight onto his boss, who agreed with me that the heights could remain as is.

Yooj

Where there is material change to the building then part m 's height rules apply.
Even these rules are permitted to be broken in certain circumstances, but prob not in 95% of cases.

Not for a dwelling. From Approved Doc M:
"The requirements of this Part do not apply to:

(a) an extension of or material alteration of
a dwelling; or

(b) .........."

Not that I do domestic work these days but if the whole place is being completely rewired then I can't see why it's a problem to install the new boxes etc at the correct heights for current requirements as you have to chase out & probably reposition/install new.

If it was a partial rewire/atleration then I'd agree that, for asthetic reasons, they should match the existing. Unless of course it's one of those houses where it's been modified several times & f**k all matches up any way!

If I was the customer it's what I'd be saying.

That only applies to M4, the switch height requirement is in Part M1 which does apply....

-------------------------
Regards

Martyn.

Only a mediocre person is always at their best



www.electrical contractors uk.com

But 99% of the time on domestic rewires the tubes/capping and boxes stay, so do you think the customer is going to want to redecorate every room?

Not as I read it. They have set the page up as up as a 'requirements' column and a 'limitations' column. In the limitations column you have:
- two limitations that apply to this Part (ie all the requirements of Part M);
- a limitation to the application of Requirement M2; and
- a limitation to the application of Requirement M3.

.....as I read it.

Think i agree with Martyn here. In fact I only posted that it mustn't be "less easy" than before, because i had misread Martyn's first post.

Umm you maybe right but given that requirements in "Dwelling's" is mentioned multiple times in the document you may not.

Clear as mud

-------------------------
Regards

Martyn.

Only a mediocre person is always at their best



www.electrical contractors uk.com