Do the 17th Ed regs apply in this scenario?

[emither]

I am going to modify the hallway and landing lights in my home. The downstairs hallway has a 2 gang switch and the landing has a 1 gang switch. It hasn't been wired very well as if you switch the landing light on upstairs you can't switch it off downstairs.

I am thinking of rewiring it to two 2 way 2 gang switches, so that both lights can be controlled from both switches. I am not sure if the new 17th regs apply, as the cable will not be 50mm deep in the walls or be mechanically protected, will the lighting circuit (currently 6amp MCB) have to be RCD/RCBO protected? Or do the regs not apply in this instance as it is a modification to an existing circuit?

 

[jockspark]

the problem with the switching may not be that difficult to solve
it sounds like the 2 way strappers have been connected incorrectly
if you can identify them and correct them it should save you
redesigning the lighting

 

[comms]

The 17th apply to all electrical work now being undertaken.
The rcd/rcbo thing, well if you are not extending the circuit in any way but are replacing like for like accessories then no rcd/rcbo is required.