Electric Supply for Garden Office

[Cliffoshay]

I'm in the process of building a garden office which will need an electricity supply for a couple of computers, printers etc (prob 4 double sockets in total) a 1kw panel heater as well as a lighting circuit.

I would like to do as much as I can to save money where possible. I'm happy to source armoured cable and a consumer unit and bury the wire in the lawn, under the decking and through the house to the house supply.

I'd then employ an electrician to connect everything up.

The problem is, I need some guidance on what specification cable etc to use.

Any thoughts?

Thanks in advance

 

[ban-all-sheds]

I'd then employ an electrician to connect everything up.

If you're in England or Wales it doesn't work like that - the electrician has to sign legal documents to say he did the work and it all complies - you can't just get one along to accept responsibility for what you've done.

The problem is, I need some guidance on what specification cable etc to use.

So you should find your electrician, agree with him what work you can do - I'm sure he'll be delighted for you to dig the trench, for example, but there are rules for how deep etc, so he'll want to "direct" you in that, and inspect it before the cable goes in.

And you may as well have him supply the materials - firstly he may not want to use the make of CU you choose, you won't get a warranty if you supply, and it'll be cheaper anyway.

Any thoughts?

There's lots involved.

• 
  
  
  
• //www.diynot.com/wiki/electrics:mcbtocable
  
  
• http://www.tlc-direct.co.uk/Book/4.3.1.htm (all subsections)
  
  
• http://www.tlc-direct.co.uk/Book/4.3.11.htm
  
  
• http://web.archive.org/web/20080213151445/http://www.kevinboone.com/cableselection_web.pdf
  
  
• http://www.tlc-direct.co.uk/Technical/Charts/VoltageDrop.html
  
  
• http://www.tlc-direct.co.uk/Book/5.3.1.htm
  
  
• //www.diynot.com/wiki/electrics:mcb2
  
  
• http://www.tlc-direct.co.uk/Book/7.13.3.htm
  
  
• http://www.tlc-direct.co.uk/Book/8.1.1.htm
  
  
• //www.diynot.com/wiki/electrics:swa-gland
  
  
• http://electrical.theiet.org/wiring-matters/16/elect-inst-outdoors.cfm?type=pdf
  
  
• //www.diynot.com/wiki/electrics:part-p
  

 

[pjcomp]

There's also the question of afterwards - something doesn't work, you all him back, "nah, you did that bit, guv, nothing to do with me". As BAS says, work with the electrician, don't try to second guess someone. If you present a half-finished job most of us would turn round and walk away rather than sign for it.

PJ

 

[Cliffoshay]

Thanks for the replies, I appreciate it.

I was looking at complete garden office kits that include everything (except base / foundation) sockets, wiring, lighting, CU. They (or I) assemble it and state an electrician will need to connect it to the house supply.

The thing is that as my office has to be bespoke (it's an irregular shape) I'm not able to buy a kit - but instead buying everything myself. So I want to be in the same position as if I were buying a kit - if that makes sense?

 

[bernardgreen]

Check with the electrician you intend to use and then install ducts in the trench at the depth he specifies before laying the concrete base. Take photos of the trench and duct with clear indication of the depth. The photos will be useful if the building control officer asks for proof of the depth. It also means the cable route can be bought up through the floor inside the building and not have to go through the wall without the cable having to be protected during the building work.

Put in at least two ducts. one for SWA mains cable and one for phone, comms and other cables.

The expense of a duct for the SWA is worth paying as it makes replacing a damaged cable much easier and cheaper.

 

[ban-all-sheds]

They ... state an electrician will need to connect it to the house supply.

They are glossing over how much that actually entails. "Kit" or no, all the circuits in the building have to be tested, the connection to the house has to be properly done....