On or around Tue, 11 Mar 2008 10:03:39 -0000, "William Black" enlightened us thusly:
yeah, but if you're a sensible DIY bloke who's capable of understanding basic wiring requirements, you can't justify it.
and domestic installation is, now, mostly done by electricians, since no-one else can be bothered to get certified. Even in new build, I'd imagine they get a sparks in to do the wiring.