Wiring for garden office - can I spur off an external socket?

[thatsimpsongirl]

Thanks @pc1966 and @brianmoooore - and thanks in general to everyone for all the replies, I didn't expect to receive so much good advice in such a short space of time!

I note your points re the cable size / whether there are any other connections to the 32A MCB / RCD protection (annoying but not insurmountable). The completion cert is not yet done as there are a few things still to be connected up (kitchen appliances etc.) but will show this to whoever does the work outside once I receive it.

Obviously I will be getting a qualified professional for all the studio electrics but it does seem to make a difference in how seriously I am taken on site if I'm well informed (at least as far as I can be as a non-specialist). Just wish one of you guys had been my electricians in the first place!

Thanks again

Nikki ?