1 way 2 gang (probably no neutral) to smart switch

[Ponja]

No, just make sure the two lights are controlled by the same fuse/circuit breaker in the CU.

They're on the same breaker, but so is all the lighting upstairs (labelled on breaker as well).
Is this an issue?

Why does same breaker mean continuous circuit (I presume that this means neutral and live going through all lights).
Couldn't one breaker control multiple circuits, or maybe that's just not done.

 

[EFLImpudence]

They're on the same breaker, but so is all the lighting upstairs (labelled on breaker as well).
Is this an issue?

Therefore all those lights are on the same circuit. No, not an issue.

Why does same breaker mean continuous circuit

I am not sure continuous is the relevant word.
That is the definition of a circuit - all items on a particular breaker or fuse.

(I presume that this means neutral and live going through all lights).

Yes - the live and neutral from a particular breaker or fuse.

Couldn't one breaker control multiple circuits, or maybe that's just not done.

No. It is not possible. That would be one circuit.


If one of the lights in question were not on the same circuit then, after the alterations, the live to it would come from one breaker and the neutral would return to another breaker.
This is potentially dangerous.
Plus, if the lights were on different RCDs then they would both trip when either light was turned on.

 

[EFLImpudence]

If one of the lights in question were not on the same circuit then, after the alterations, the live to it would come from one breaker and the neutral would return to another breaker.

That is a bit ambiguous.

What I mean is the live from another breaker which is not switched off would mean that that neutral could be live when disconnected from the light.

 

[Ponja]

Therefore all those lights are on the same circuit. No, not an issue.

For future reference, this seems to suggest that any circuit with multiple lights would allow you to change the switched live to neutral in the ceiling rose. This would make it an extremely common solution. I'm not sure why I haven't seen it mentioned throughout extensive googling. Then what's all this fuss about no neutral smart switches?

 

[EFLImpudence]

For future reference, this seems to suggest that any circuit with multiple lights would allow you to change the switched live to neutral in the ceiling rose. This would make it an extremely common solution. I'm not sure why I haven't seen it mentioned throughout extensive googling. Then what's all this fuss about no neutral smart switches?

Not "any circuit with multiple lights".

You would not have been able to do it if there had not been two switches wired independently.

 

[Ponja]

Ok it finally clicked, that explains why!