Should a shed have an earth rod?

[Shelectrics]

Hi everyone, I've been asked to install a consumer unit in a summer house with circuits for light and power. The owner has already laid SWA, buried it, the 20m from main consumer unit, in 6mm. It won't need anything like that though, it'll be supplying a few DIY power tools, maybe a heater and the lights. My question is, does it need an earth rod? So many outside consumer units don't, but I think I once heard someone say it should.
Thanks!

 

[ImpededLoop]

Supply to a detached outbuilding | Technical advice by NICEIC

Many domestic premises have one or more detached outbuildings such as a garage, garden shed or greenhouse, that require an electrical supply from the installation in the house for lighting or small power.

www.voltimum.co.uk

There's lots of other articles online in addition to this one.

 

[DPG]

Hi everyone, I've been asked to install a consumer unit in a summer house with circuits for light and power. The owner has already laid SWA, buried it, the 20m from main consumer unit, in 6mm. It won't need anything like that though, it'll be supplying a few DIY power tools, maybe a heater and the lights. My question is, does it need an earth rod? So many outside consumer units don't, but I think I once heard someone say it should.
Thanks!

You need to go by the regs, rather than something someone may have once said.

Why might an outbuilding need to be TT?

Or do you mean an earth rod in addition to the 'normal' earth?

 

[loz2754]

A lot of questions need to be asked and answered before taking on this job.

For instance is the swa correctly installed in line with regulations? What earthing system is in use in the house? What protective device will be used to supply the new feed?

 

[timhoward]

I'd be very surprised if an earth rod was needed.
Before doing anything else IR test the pre-installed SWA, between cores and to the armour. I've been burned twice with pre installed dead-shorts.

And as @loz2754 said there are quite a few factors to this design.
Earthing in house is a factor
Protective device in house is factor.
Presence of anything in summer house that needs bonding is a factor too.
Thinking about where RCD protection is would be good, ideally avoiding outside faults affecting the house.

These jobs seem simple but there's a fair bit to think about.