Wiring a garage extension

[Matt]

The plasterers are coming next week so I need to lay the cable for a planned garage extension before the boards go up - the only problem is that my sparky's on holiday (probably spending the cash from my last job)!

The garage will have a maybe a couple of lights and possibly a workbench for hand held power tools at some stage.

The house consumer unit is 30' away from the wall where the cable exits the house, and the garage is at the end of an 80' garden.

What type of armoured cable do I need to go under the garden (screwfix links appreciated)?

Does the armoured continue to the consumer unit, or is it connected to something cheaper once inside the house?

I'm not connecting anything - just putting the wires down.

[Christian McArdle]

I would not export the earth for this, but use 2 core SWA cable, a local earth rod and local TT earthing. At the garage end, have a "garage" consumer unit with an RCD and a couple of MCBs.

You can swap to standard T&E once indoors. Although this is not compulsory, it is recommended, as much for ease of installation as cost.

Size wise, I would use 10mm, both for the T&E and the SWA. This will allow you a 32A circuit to the garage.

If you want it on the cheap, then 6mm cable is OK for a 20A circuit, but is it worth it for the saving?