Running power to outbuildings

[JDLDIY]

Hi there. The situation is that I have just built a shed half way down my back garden and in the future we will want a log cabin/office at the bottom of the garden and maybe a workshop/tool shed down there. Currently the house has old wiring which will need replacing but I don't want to do that before we do a large building project to extend and renovate. Currently the electric meter is in a cupboard on the front wall of the property.

I'm desparate for power in the shed, can we
1. Connect to the power in the meter cupboard, maybe installing a small consumer unit to run it from?
2. I don't want to be digging up the concrete path as yet so can we run the cable along the bottom of the fence, behind bushes etc to the shed but at ground level?

Last time many years ago I had to deal with this I dug a trench a meter deep, installed armoured cable on sand (I think) filled it a bit, put that warning tape down, then the electrician connected up both ends. So I know that's preferable but I'm not able to do that just yet. Also, often when you're out and about you see cables running at ground level in pub gardens, stately home gardens etc, so is this ok?

Many thanks!

 

[ericmark]

It depends on so many factors, one is how much power do you require, and how often. I would say you need to decide what an when. I don't like the idea of a temporary supply, as so often it ends up not being temporary, however I have supplied a caravan in the garden with a flexible cable for years, however each time the caravan is used the cable is wrapped up, so also checked.

Since it seems you are working to a bigger plan, temporary may be an option, however as far as the permanent installation goes, it does matter where you live, Wales is tighter than England, and if you want a paper trail for what your doing, then involve an electrician now, tell him your plans, and use his advice, this means he can sign the paperwork, even if he does not do the job, he is in control, and that matters.

I have just moved house, and paperwork does matter, we can advise all we want on a forum, but it's the guy who signs the paperwork that matters.

 

[Taylortwocities]

Whssign

• Taylortwocities
• 16 Jul 2016

What he said

 

[JDLDIY]

It depends on so many factors, one is how much power do you require, and how often. I would say you need to decide what an when. I don't like the idea of a temporary supply, as so often it ends up not being temporary, however I have supplied a caravan in the garden with a flexible cable for years, however each time the caravan is used the cable is wrapped up, so also checked.

Since it seems you are working to a bigger plan, temporary may be an option, however as far as the permanent installation goes, it does matter where you live, Wales is tighter than England, and if you want a paper trail for what your doing, then involve an electrician now, tell him your plans, and use his advice, this means he can sign the paperwork, even if he does not do the job, he is in control, and that matters.

I have just moved house, and paperwork does matter, we can advise all we want on a forum, but it's the guy who signs the paperwork that matters.

Hi there, many thanks for taking the time to reply.

Yes I will be doing this properly, using a qualified electrician, but I don’t have one as yet and I just wanted to find out whether what I’m asking is possible or not. I.e.can I run SWA over the ground, either temporarily or on a permanent basis and can we come off the electric supply in the exterior meter cupboard before it runs inside to the old CU.

I just wanted to find out whether this is possible in principal ‘cos if not I’ll avoid wasting an electrician’s time in calling them out to look and leave the whole thing till we dig the whole place up and I’ll be using extension leads in the meanwhile. Hope that makes sense.

 

[ericmark]

To come from the outside assess meter cupboard would be a lot of work, you would need at least 16 mm² cable or some sort of overload trip, if the outbuilding was a granny flat then this may be best option, but in the main it would come from either the consumer unit (CU) or a fused connection unit (FCU) but the main thing is how much power do you want?

Up to 13A FCU likely best option.
13A to 45A a MCB in main CU.
Over 45A henley blocks and a cartridge fuse.

The price jumps with each option, so best is talk to the electrician selected to do the job.

 

[AndyPRK]

How much power do you require in the short term ?

 

[Taylortwocities]

How much power do you require in the short term ?

And in the long term

 

[JDLDIY]

Ah ok, I see. Well this is a good point because I’d actually like to be able to run my air compressor off the electric and this routinely trips the mcb in the garage - I think it really needs a 20A supply. Long term I’d still like to run that as well as a fridge, computers, TV etc etc, it’ll need to have the power you have in the house for sure. I hope that makes sense.

Oh, and quite possibly under floor heating, an electric shower as well.

 

[Taylortwocities]

What you have just described is more like a small house. This is way outside the remit of a DIY project, let alone spurious advice given on an Internet forum. As Eric said

The price jumps with each option, so best is talk to the electrician selected to do the job

You’ll need a registered and competent electrician. Find one here
http://www.electricalcompetentperson.co.uk/

 

[JDLDIY]

Thanks for the link, I’ll have a look at that. I am not intending to do any of this DIY!! What I was after was just getting a feel for what is involved and the available options which I can compare with what I’m told when I get people around. The deal breaker is whether we can connect to the electric without touching the old CU as that needs replacing but I don’t want to do that until we rewire as it’ll go in a different place....but also if the cable needs to be sunk below ground that’s also a deal breaker in the short term because at the moment I don’t want to be digging up my concrete path.

Oh, and another question - can the power be taken to the shed half way down the garden and then further to the outhouse at the bottom? Or does it need to be totally different circuits?

 

[EFLImpudence]

The deal breaker is whether we can connect to the electric without touching the old CU as that needs replacing but I don’t want to do that until we rewire as it’ll go in a different place....but also if the cable needs to be sunk below ground that’s also a deal breaker in the short term because at the moment I don’t want to be digging up my concrete path.

Can't tell from the internet.

can the power be taken to the shed half way down the garden and then further to the outhouse at the bottom?

Yes.

 

[Taylortwocities]

Here’s your main issue

Long term I’d still like to run that as well as a fridge, computers, TV etc etc, it’ll need to have the power you have in the house for sure. I hope that makes sense.

Doesn’t need so much in terms of power.
On the edge of 30A, maybe, including your compressor start up load.

But. Your real plan to add this

Oh, and quite possibly under floor heating, an electric shower as well.

Is a completely different ball game. It’s going to need a big fat cable and suck up as much power as the actual house itself.
It may be that the house supply cannot even support this large additional load and you’d need a complete new supply.

You need advice, on site.

 

[JDLDIY]

Right, that’s great advice, much appreciated. Very useful and has given me a decent starting point - looks like I might need to rethink the electric shower for a water fed option for starters.