wiring outside lights and outbuilding power setup

[psprigs]

I have a house and outbuilding, im looking at putting power to the outbuilding from the house supply,
I was thinking as im unable to add into the fuse box,
run protected in some way 2.5mm cable from house to outbuilding, from the house, take a spur from a existing socket ring main into a surface mounted 30ms rcd socket with a 13amp socket. Then put a plug on the 2.5mm cable, effectivly adding a plug socket and extending the other end to the outbuilding....
The outbuilding will maybe power a few 150w spot lights, and inside lighting, nothing that a normal socket wouldnt handle, on the outbuilding end, prob just have a few interior sockets for lighting...
So i guess its one big extension lead with rcd of the house main...
Is there a better more professional way to do this?
Anything which can be more safer?
The cable will be run in the plastic trunking along a wall rather than dug into the ground.

Thanks
Paul.

 

[breezer]

try a search on power to outbuilding, shed,garage

 

[CookyMan9999]

all sounds ok but from what i can understand be careful not to spur from a spur. Also take into consideration the buildinngs regs part p and so on. This would probably be the quickest, easiest and cheapest way of carrying out your project but are you going to test your additiion?

 

[breezer]

all sounds ok but from what i can understand

no it isnt

 

[psprigs]

Sorry about that, should of searched before asking a question, just found the link to this site...

Within 10 mins of reading outside jobs from others, and looking at some site links from here, ive got some better safe and long term ideas which would be safer.

I guess really my only question from here which ill find answers on this forum is, over 40 meters, what size cable would be suitable for under 3kw 13a max applications?

 

[Adam_151]

not less than 4mm² (but could be bigger depending on other things)

ELFI
TN-C-S equip zone?
Final circuit characteristics

 

[securespark]

But you'll have fun getting the 4mm² into a plugtop...

(This is not the done thing, as I'm sure you now realise!)