Running electric to an outdoor building

[CardiffArchie]

Hi,ive recently had a garage built,it is about 25 mtrs away from the house.
although im not going to do this myself,i just want to know whats to be done so i can get an idea of how much it will cost to install electric in there.It's nigh on impossible to connect to my existing CU,but people tell me that it can be done via the nearest 3 pin wall socket.
BTW,i would like to set up a little workshop in there,running lights,drills etc,but not necessarily all at the same time.
Any ideas?

 

[Electrifying]

So you're going to turn the lights off when you drill?

 

[CardiffArchie]

So you're going to turn the lights off when you drill?

I was looking through the screwfix forum for a similar answer and noticed that someone said "go to DIYnot" they'll help you,and you come out with something like that.
Ok,i'll only use the drill in daylight hours.

 

[Monkeh]

Yeah, drills draw a whole 13A!

More seriously: You'd be better off doing it properly rather than as a spur. You'll need an electrician to come over and quote. Get three or four in (just not at the same time).

 

[big-all]

the cost off supplying for a 5amp drill or a 13 amp kettle is not realy that much more as all the ground work and electrician costs are the same the larger cable size is the only difference
25m is a heck off a long way but providing you do the donkey work the total cost is likley to be between 3 and 4 hundred pounds but thats just a helpfull verry unacurate guess

 

[Electrifying]

So you're going to turn the lights off when you drill?

I was looking through the screwfix forum for a similar answer and noticed that someone said "go to DIYnot" they'll help you,and you come out with something like that.
Ok,i'll only use the drill in daylight hours.

The first thing you need to get is a sense of humour.

There's no problem running the power from a socket outlet (you would just be restricted on the amount of current you can draw) - but it depends on the main installation.

For example, the type of earthing system?, any bonding requirements in garage? - without a lot more information it's impossible for anyone to help you.

 

[CardiffArchie]

So you're going to turn the lights off when you drill?

I was looking through the screwfix forum for a similar answer and noticed that someone said "go to DIYnot" they'll help you,and you come out with something like that.
Ok,i'll only use the drill in daylight hours.

The first thing you need to get is a sense of humour.

There's no problem running the power from a socket outlet (you would just be restricted on the amount of current you can draw) - but it depends on the main installation.

For example, the type of earthing system?, any bonding requirements in garage? - without a lot more information it's impossible for anyone to help you.

Ok,where can i get the sense of humour from,secondly what info do i need to give.Cheers

 

[Electrifying]

The main issue is the earthing system at the house.

There are three options:

If it's TT (via an earth rod at the property), then running a cable from a socket outlet to the garage wouldn't be a problem.

If it's TN-S (a seperate earth provided by the DNO), this also shouldn't present a problem.

In both of the above cases you could run a 3-core SWA cable from the socket outlet (via a fused connection unit) to your garage.
You will, of course, be restricted to the amount of current you can draw, by the fuse in the FCU (13 A)

If there are gas/water pipes, or any other metalwork, entering the garage (or if the garage itself is metal framed), then there are bonding requirements to consider.
This would mean using a larger CSA cable for the garage supply, or running a seperate bonding conductor to the garage.

The third system is TN-C-S, and although it's still possible to supply the garage using the method described, there are other factors to take into consideration - really an electrician should make the decision when assessing the job.

I may have missed a couple of things out, but I'm trying to explain things in a way you'll understand.

Although it seems a simple job to just run a supply to your garage, it isn't always the case.

 

[ban-all-sheds]

Hi,ive recently had a garage built,it is about 25 mtrs away from the house.

Presumably this didn't come as a surprise, so why didn't you think about the electrics, and get someone to plan it for you so that when the builders were there with labour, mini diggers, concrete etc, they could have done the trench for the supply, ensured it came up through the garage floor so that you wouldn't need to cut through it again?

It's nigh on impossible to connect to my existing CU,

You might be surprised what an experienced pro can do.

but people tell me that it can be done via the nearest 3 pin wall socket.

It's not what people tell you that matters, it's what your electrician says can be done that matters, and the only way to find that out, and to get accurate pricing, is to get a few in to look at the job in the flesh and discuss the options. As ever, personal recommendations are always the best way to find a reputable tradesman, but if you're having to go ahead without much in the way of those, or references, don't put any store by registration itself - sadly it is possible to become registered with woefully inadequate qualifications and zero practical experience. You don't have to spend long here to see people cropping up who are registered and "qualified", but who are clearly seriously incompetent in reality and who should not be charging for their services. Here is the most recent one. I'd bet what's left of my pension that when he says "I have Part P" that he means he's been through one of the quick "Domestic Installer" training courses.

It's your money, £'00s of it, and you have every right to ask prospective tradesmen what their qualifications are. Just being listed here is not a good enough guide. No genuinely experienced electrician, with the "full set" of C&G qualifications will mind you asking - in fact he will wish that everyone was like you.

I feel sorry for people who have been misled by training organisations and (shamefully) the Competent Person scheme organisers into thinking that a 5-day training course, a couple of trivial examples of their work and some basic understanding of how to use test equipment will make them an electrician, but not sorry enough to agree with them trying to sell their services to Joe Public.