Power to shed

[ban-all-sheds]

Even before the latest change to the Building Regs, notification was not a requirement for CUs or new circuits in Schedule 2 Class 6 exempt buildings.

i.e. most sheds unless they were less than 1m from the property boundary.

 

[JohnW2]

Even before the latest change to the Building Regs, notification was not a requirement for CUs or new circuits in Schedule 2 Class 6 exempt buildings. i.e. most sheds unless they were less than 1m from the property boundary.

Agreed. However, if the feed to that installation in an outbuilding was (as would usually be the case - albeit not with the OP's situation in this thread) a 'new circuit' as far as the house's installation was concerned, that would presumably render that part of the work notifiable, even today.

Kind Regards, John

 

[ban-all-sheds]

Yup.

And Part P still applies, with all that entails about proper circuit design, testing.....

 

[JohnW2]

Yup. And Part P still applies, with all that entails about proper circuit design, testing.....

...other than in the exempt outbuilding, where, seemingly, 'anything goes' as far as the Building Regs are concerned

Kind Regards, John

 

[ban-all-sheds]

No - Part P still applies there - there are no exemptions from that.

http://www.legislation.gov.uk/uksi/2010/2214/regulation/9/made

The only change to that is to add “used for domestic purposes” after “greenhouse” in 9(3)(a)

http://www.legislation.gov.uk/uksi/2012/3119/regulation/5/made

 

[JohnW2]

No - Part P still applies there - there are no exemptions from that.

Ah yes - we've discussed that before, and I had forgotten. Apologies. It's interesting that they've retained Part P, but virtually none of the rest of the Building Regs, for such 'exempt' outbuildings. It obviously makes sense to us, but I suspect that people with an interest in other tradesmight say much the same of 'their bit'!

Kind Regards, John

 

[PCAnimal]

wow! generated lots of discussion. The wiring is sound as the electrician did the tests when fitting the new consumer unit. At the time we still used the old shower when the bathroom was done he terminated it in the loft but I asked him to not to remove from the consumer unit.
I can't remember the rating.

I assume even using SWA it should go through trunking underground. I am going to run an alarm cable up there.

The plan is to take the dedicated feed from the loft to a new MCB in the shed which will then run a light and sockets. Nothing heavy typical DIY stuff!

When I moved into the house I found the power supply to the shed was fed from the lighting circuit down the wall with standard cable and through plastic trunking on the fence. Needless to say I disconnected it immediately

As an estimate of distance the cable will probably run about 30m tops.

 

[ban-all-sheds]

wow! generated lots of discussion. The wiring is sound as the electrician did the tests when fitting the new consumer unit.

Anything new you add will require testing, as per the details linked to above.

I can't remember the rating.

Then you need to go and look, as it affects the cable size, as per the details linked to above.

I assume even using SWA it should go through trunking underground. I am going to run an alarm cable up there.

SWA can just be buried, if you prepare the trench as per the details linked to above. Alarm cable can't.

The plan is to take the dedicated feed from the loft to a new MCB in the shed

Housed in what?

which will then run a light and sockets.

Can't have those on the same MCB.

You really should start reading some of the basics in the books linked to above.

As an estimate of distance the cable will probably run about 30m tops.

So you can do the voltage drop calculations and EFLI prediction as per the details linked to above.

 

[JohnW2]

[SWA can just be buried, if you prepare the trench as per the details linked to above. Alarm cable can't.

That's certainly the proper and 'official' view. However, as an anecdote ...

Some 26 years ago, when I moved into my present house, I inherited a cable between house and greenhouse (probably about 50 metres) which was being used just for an intercom. It was a standard, small 8-core PVC 'signal cable' which was buried directly, not very deeply. Goodness knows how long it has been there in total but, 26 years after I inherited it, it does not seem to have been eaten, destroyed by gardeners or degraded. It remains functionally fine, and (when I last checked) between-cores IR (at 500V, even though the cable is probably only rated at 50V or so) is also still fine.

I'm not suggesting that anyone does it, but the fact is that buried 'alarm cables' (particularly if buried at a sensible depth) might well last a lot longer than many would think!

Kind Regards, John

 

[dhutch]

I would still put in a pair of ducts if I was digging any size of trench, even is the swa wasnt in either of them....


Daniel

 

[JohnW2]

I would still put in a pair of ducts if I was digging any size of trench, even is the swa wasnt in either of them....

No argument with that. Ducting is relatively cheap, and I don't like digging!

Kind Regards, John

 

[dhutch]

Going back to topic, the frequency at which these sorts of topic come up it would be really great if we had a wiki page or simular on the topic of 'Adding power to a shed or outbuilding' to be a first port of call. Obviously there are so many perms and comms it could never be a definative guide, but it would be fairly easy to put together something that would cover the bulk of options in a fairly concise document which wouldnt be too hard to keep upto date.


Daniel

 

[JohnW2]

Going back to topic, the frequency at which these sorts of topic come up it would be really great if we had a wiki page or simular on the topic of 'Adding power to a shed or outbuilding' to be a first port of call. Obviously there are so many perms and comms it could never be a definative guide, but it would be fairly easy to put together something that would cover the bulk of options in a fairly concise document which wouldnt be too hard to keep upto date.

I've been thinking that, too - but I see a bit of problem. Sure, it would be pretty easy to put together something which described all the 'options'. However, particularly in relation to the 'earth' issues, there clearly is a range of opinions as to which of those options are the most desirable (or even 'safe') which I think would probably make it difficult/impossible to offer any truly useful 'guide' as to how things should be done.

Kind Regards, John

 

[dhutch]

The earth issue one of the biggest potential areas to get wrong I guess, but equally while Im not fully au fait with it myself i would not expect it would be too hard to write a paragraph on what the options are in terms of when you can export an earth, and what is required if you cannot.

Daniel

 

[JohnW2]

The earth issue one of the biggest potential areas to get wrong I guess, but equally while Im not fully au fait with it myself i would not expect it would be too hard to write a paragraph on what the options are in terms of when you can export an earth, and what is required if you cannot.

As I said, I'm not so sure. The options/possibilities are easily stated, as is what one should do if one doesn't export an earth, but the crucial question of whether one should export an earth is the one which is subject to a range of opinions. For exanple, at one extreme there seem to be those who feel that one should never export a TN-C-S earth, whilst at the other extreme there seem to be some who are comfortable for that to be done, particularly if the outbuilding has no metal structural elements.

Kind Regards, John