Guys I have always used 1.5mm for lighting circuits and always use the loop in box method. Looking back some of the lighting circuits I have placed in single and indeed double boxes sometimes crams conductors and can get messy. I just need forum inputs to start or not to start using 1mm generally, and so the question begs - How many of you are happy to use 1mm in lighting circuits? Breaker sizes and loading etc I have no problem with, and of course the cpc is the same size as 1.5 so no probs there or owt. Are you all happy with using 1mm largely in domestics? Would you be happy running 1mm for 5 amp so's or would you use 1.5mm in this scenario? I use 1.5mm myself at present. Security lighting I usually do as dedicated, and would not use 1mm for that type of thing. Any inputs greatly appreciated.