Much as I tend to be pretty cynical about such things myself, I doubt that it was a significant part of the reason for 'adding SPDs to the regs' - since, as we know, they never have a problem in finding excuses for creating a new amendment or edition of the regs, even in the absence of some new-fangled device for them to include! ... and, of course, they have to regularly 'update' the regs to take account changes in CENELEC.
As I've said, my personal view is that SPDs are one of those things which appeared, and is heading towards 'being required' simply because it became technologically possible to mass-produce them (and for people to make a fortune by selling and installing them), without much (if any!) serious consideration of whether or not there was actually a true need - and particularly odd for BS7671,since it's really the first rime it has included regs which have really got nothing to do with 'personal safety'.
