Power to detached garage when no spare way in house CU?

[Sponge]

My house was rewired last summer and the CU replaced. It's in a small corner cupboard in the hall and cannot be replaced with anything larger. After everything else has been hooked up, there is no space left (empty way) to supply the garage.

The electrician has left the cable to the garage disconnected (loose) in the cupboard below. The cable runs from the front of the house to the back, under the floor, then connects (metal junction box) to an underground cable for the short (2-3m) run to the garage.

I want to renew the garage's existing circuits (fusebox, socket and light) with materials from this century but at the end of the day, how will it all be supplied? I'm curious as to how an electrician will do it. What options are there? The pros and cons?

Am I allowed to rewire the garage myself and then get an electrician to connect it to the (house) supply? Or should I start getting quotes for the whole job?

All I'm after is two strip-lights and maybe 2 double sockets for a lawnmower and charging the powertools.

I'll admit to wanting to do as much as I can myself, but for record will not touch the CU in the house and/or do work I am not qualified/competent to do. I've had the whole house professionally rewired, at great cost, so do not want to jeapordise the installation/certification.

I can't refer to the electrician that did the rewire for guidance.

EDIT: Added pictures.

Untitled

• Sponge
• 21 Apr 2014
• 1

Untitled

• Sponge
• 21 Apr 2014
• 1

Untitled

• Sponge
• 21 Apr 2014
• 1

Untitled

• Sponge
• 21 Apr 2014
• 1

From left to right:

• Downstairs sockets.
  Kitchen sockets.
  Socket below CU.
  Upstairs Lights.
  Upstairs sockets.
  Cooker.
  IT sockets (understairs cupboard with NAS, switch, patch, 3xHDD).
  Downstairs lights.

 

[AndyPRK]

Well if its only for lighting and charging you could bodge it upto a 13a plug and plug it into a socket.

Simple cheap and effective.

Are you saying the garage electrics are outdated?

 

[sparkwright]

He should have made provision for your garage.

It may be possible to supply the garage via a 13 amp fused spur from the socket circuit.

Or perhaps the circuits in the consumer unit can be juggled about to make a spare way.

Or maybe there is space to fit a switch fuse for the garage, fed from the consumer unit tails.

Photos needed here to give the best answer.

 

[JohnW2]

My house was rewired last summer and the CU replaced. It's in a small corner cupboard in the hall and cannot be replaced with anything larger. After everything else has been hooked up, there is no space left (empty way) to supply the garage. ... The electrician has left the cable to the garage disconnected (loose) in the cupboard below. The cable runs from the front of the house to the back, under the floor, then connects (metal junction box) to an underground cable for the short (2-3m) run to the garage.

That sounds all a bit odd and short-sighted! Surely the electrician must have realised that there was going to be a subsequent need to supply power to the 'garage cable', and one would have expected some provision to have been made at the time!

I want to renew the garage's existing circuits (fusebox, socket and light) with materials from this century but at the end of the day, how will it all be supplied? I'm curious as to how an electrician will do it. What options are there? The pros and cons?

As a variant of what has already been suggested, if the electricity requirements in the garage are very modest, the supply to it could probably be wired as a 13A 'fused' spur from an existing sockets circuit in the house. If you did that, you wouldn't really need a CU in the garage - the cable could be connected directly to the socket(s), with a 3A fused connection unit ('FCU') off that for lighting. Otherwise, given no spare capacity in your CU. the only other option would really be for the electrician to take of a new feed from the supply prior to the CU for the new circuit.

Am I allowed to rewire the garage myself and then get an electrician to connect it to the (house) supply? Or should I start getting quotes for the whole job?

You are 'allowed' to do any electrical work if you are competent, but a few jobs need to be notified to the local authority's Building Control dept. (which is very cheap for a registered 'self-certifying' electrician, but very expensive for anyone else!). Assuming that you are in England, very little is now notifiable, but installation of a 'new circuit' is one thing which is. In theory, you could get a self-certifying electrician to install some 'token' new circuit, and then you could 'extend' that circuit to your heart's content without needing to notify. Whether that would be much cheaper than letting the electrician do the whole job, I can't say!

Kind Regards, John
Edit: damnit - typed too slowly yet again

 

[AndyPRK]

I imagine the garage electrics were so old or unsafe the electrician wasn't prepared to connect it up.

 

[JohnW2]

I imagine the garage electrics were so old or unsafe the electrician wasn't prepared to connect it up.

Yes, probably, but I don't think that really excuses not having made some provision for subsequent connection of the garage circuit - e.g. installation of a switch fuse or even an FCU off some existing circuit.

Kind Regards, John

 

[AndyPRK]

A bit too easy for the owner to connect it up then!

 

[JohnW2]

A bit too easy for the owner to connect it up then!

I suppose so, but leaving the end of the cable dangling near the CU could also tempt the owner to do all sorts of things

If the CU were bigger, I could understand the electrician leaving out, for the time being, the MCB for the garage, until the garage wiring is sorted out, but leaving a situation in which there clearly was not adequate provision for the number of circuits that the owner was going to need seems less than ideal.

Kind Regards, John

 

[AndyPRK]

It's already been said there its room for a bugger cu.

Maybe the owner didn't want the decoration disturbing.

Electrician following customers wishes.

 

[JohnW2]

It's already been said there its room for a b*****r cu.

I presume you mean "...there isn't room for ...", which is what the OP said.

Perhaps I wasn't clear. I was merely saying that if the CU had been larger (with adequate capacity to accommodate a garage circuit) (which it isn't), I could have understood the electrician leaving out 'the garage MCB' for the time being, because (s)he wasn't happy with the garage wiring - but I think it's a bit different to undertake a 'whole house re-wire' and leave no provision at all (even if separate from the space-limited CU) for a circuit that it was known would be needed.

Maybe the owner didn't want the decoration disturbing.

Possibly, but I would have doubted that it was realistic to have a 'whole house re-wire' without some disturbance to decoration!

Kind Regards, John

 

[sparkwright]

You mean bugger all room for a bigger cu.

Hopefully we will see some photos.

If it turns out to be a dual RCD board as opposed to all RCBOs then we can have a good moan...

 

[AndyPRK]

Good point about the rewire. I overlooked that.

Silly swear filter. I only said big ger CU.

Humm maybe my phone autocorrected and added a swear word!

 

[JohnW2]

Good point about the rewire. I overlooked that.

Yes, perhaps it hasn't been clear, but that has been my point all along. I would have thought that when an electrician undertakes 'a whole house rewire', (s)he should at least advise the customer (who may, of course, disagree) to have provision provided for at least the number of final circuits currently contemplated (and, ideally, a spare or three), even if circumstances dictated that this would require two CUs, or 'a CU plus something else'.

Kind Regards, John

 

[JohnW2]

Humm maybe my phone autocorrected and added a swear word!

Autocorrection and 'predictive text' usually 'learn'. So, if you commonly type that particular swear word into your phone ....

Kind REgards, John

 

[AndyPRK]

I thought someone would say that lol