David,
You've raised a couple of interesting points that I was going to quiz you about!
As you've stated, down here in Sassanach-land compliance with the IEE Regs/BS7671 is not a legal requirement for residential wiring (commercial is different, as it would now come under the auspices of the Health & Safety at Work Act).
I've seen the statements before about the IEE Regs. being quoted by Building Regularions in Scotland (not sure when that came about, but I think there's a note to that effect in my old 1966 edition).
My question: How widely do the Building Regs. in Scotland apply? Obviously a new building or some major renovation involving planning consent etc. would fall into the net, but what about just an electrical rewire? In England, that would have nothing whatever to do with Building Regs. and therefore any such Regs. would not apply.
How would this work under Scottish law? In other words, does it mean that any works that don't involve Building Regs. therefore don't have to legally comply with BS7671?
Legalities aside, does anybody actually enforce compliance with IEE Regs. in Scotland for residential work? Does this come under the jurisdiction of the general building inspector, or is there a separate inspection?
(As you may have gathered, despite traveling half way around Europe and having worked in the States etc., I've never actually been to Scotland, much less done any wiring up there!)