When Part P first came out we were told if you clip up the cable for an extension lead used in the kitchen then it needed notifying. But if you just leave it sitting in any water split from using the kettle then only the coroner needs notifying not the council. There were many more like a FCU creating a new circuit so that would need notifying.
However since time has moved on it seems will notify less and less. I found the double socket next to mothers bed was a spur, so I fitted a grid socket, switch, and fuse container to extend to some other sockets, I looked at it and thought I could with easy fit 4 fuse carriers to a double socket outlet and this would be very like the 4 fuse Wilex boxes which were used before we had type tested distribution units called consumer units. However since plastic not metal it would not be allowed. Or would it?
This is the whole problem with Part P, no one has ever been taken to court to my knowledge where they have tried to stretch the limits to what is allowed. When does a row of fuse holders become a distribution unit? If I fit a BG MCB in a Wilex consumer unit (assuming they will fit) is it still a consumer unit? OK where ordinary people are in charge we should use a consumer unit not a distribution unit. But BS7671 is not law, so you can't refer to BS7671 to work out what is allowed under Part P.
So we do have some law, if an electrician becomes a scheme member he is legally required to follow BS7671. An electrician can't say he is a scheme member if he isn't. If some one is injured due to a faulty installation it is easier to bring a court case. So in rented accommodation for the landlord to DIY if not a scheme member he is asking for trouble. But for the owner occupier Part P is really not an issue. OK he may be breaking the law, but who will catch him? In real terms unless the work is that bad it kills some one then your not likely to get caught.
I wonder now I have had my mother house rewired, what happens to all the old notifications for electric work done? How does the council know which bits have been rewired, and which are original? And more to the point does anyone care? I know because I was involved that there are still at least two compliance certificates and one completion certificate still in force. There may be another couple, but don't know if chair lift or door bell was rewired or not.
It would be no difference to before Part P, if some one is killed then some one has to rake through the paperwork, and question the people who have worked on the house to work out who if anyone made any errors. So if one of the six electricians and an apprentice was to have fitted a non maintenance free junction box, and the screws work loose and cause a fire in 2030 which kills my wife how would anyone work out who fitted that junction box? I am sure all will say "Not me mate" so how does the registering work with the council really help?
I still say forget Part P, what is important is to work safely, it really does not matter what the law says, what matters is being able to complete the work and test the work to make it safe. To know were maintenance free JB's are required, to be able to test any RCD fitted, to follow within reason all which is detailed in the BS7671 book. Ever since 1984 I have been watching out for the thought police!