Lighting Circuit Off A Fused Spur?

I would be grateful for advice on an issue regarding running a lighting circuit from a fused switched spur unit.

I had an existing outdoor 13 amp socket on an outside wall, which was a paved patio area.

I have this year built a garden room where the patio existed.

My question is ...can I run a lighting circuit consisting of four wall lights ( each one powering 2 x 20 watt bulbs) controlled by two dimmer switches from a fused spur unit , run from the outlet supply point where the 13 amp socket was previously?

I was always told mains and lighting circuits were never to be crossed! although I know that since my days these regs have changed .

I live in a cottage where running cables back to the consumer unit (four rooms away would involve digging up solid floors to re channel cables ( the rooms ceiling heights are all different, so that route is also out!)

Any help, advice, and alternatives would be gratefully accepted. Thank you.

It's  ok to do that 

And VERY common in conservatories.

And 70's council flats

Thank you for your advice and for answering...have not been in touch to thank or continue work on building project, due to fractured spine stopping play!

Hope to complete the garden room( or as the building inspectors file has it named ... The Orangery) after Christmas ...you would think that after breaking my spine in 1990 and becoming disabled I would have got used to this ...once is unlucky...twice is a conspiracy!!!

Anyway Happy Christmas all who help here !

It's as safe as taking a circuit from the board as long as you fuse down to the cable's rating.

I and we must not forget RCD's