In the coming weeks I will be re-wiring my home. For the lighting circuits i will be using 1.5mm cable. ideally I would like to run the feeds to and from each light switch so that there is a neutral at the switch for smart lighting. However to avoid more damage/decoration I will be using the existing conduits in the wall to each switch but they are not big enough for the extra cables (feed in and out) so my thought is to run a 3 core to each switch (Live, switched live and neutral) would this be satisfactory for the new regs? Also if I fail to even fit the 1.5mm 3 core in the conduit would it be wrong to run the switch cable in 1mm and the feed cables in 1.5mm?
Cheers
Cheers