Light switch route - is this legal?

[stargazer]

I’m not sure the 17th goes as far as doing away with the permitted zones, but I stand to be corrected.

EDIT, Thanks plugwash

No it does not, the "draft for public comment" of the 17th edition had that provision but it was removed before the final version.

 

[Prestonian]

As the 17th edition update says - stick a cable anywhere as long as it has rcd protection .. ( forgive me for paraphrasing !!) i think the real problem here is the fact he has made a join that when plastered over wont be accessible for inspection.

Don't think our lighting circuit is even RCD protected. There's an RCD on the left hand side of the CU next to the green labelled switches (sockets & shower). The lighting rings, smoke dets, cooker are on the right hand side with red labels under (apologies for the technical wording). Is that what you call a split board?