Sorry guys, the reason for the late reply is
a) I don't usually read the forum at the weekend
b) I hadn't expected much interest!
To answer the general sentiment of the replies:
Firstly, as has been noted, LABCs vary (apparently). So whilst I managed this in my area (West Berks), others may not. Also I can quite believe that circumstances came into too, such as the person assigned to my BC request and workload etc.
Secondly please don't think that I have done this primarily to save the cost of hiring an electrician. The main reason is that I am doing a LOT of work and it needs a lot of design (especially my lighting system), so to involve an electrician and expect him/her to do exactly what I want would probably be difficult.
Thirdly I think this is only economic/feasible for large scale work. Since I am building an extension, the BC fees were already accounted for - I did not have to pay extra for the electrical notification. Then I had to do a LOT of work (see below) to reach my current situation. It is simply not worth it and would be too expensive for minor works.
Anyway - so here's what I did:
When I bought my current house in 2006, I knew that I wanted to change some of the electrics (not only for the extension), but was only vaguely aware of part P. So the first task was for me to research it (including joining this forum). Once I had done so I came very close to deciding that I would NOT do any of the work myself. However I guess I was interested in the challenge so I went ahead.
My research had been flawed - I didn't know that part P had been revised (doh!) so I took the requirement about documentation to heart. Being an ex-design engineer from regulated industry, my idea of good documentation means detail (warning to those who want to follow my example). So I decided to start and maintain a "record of electrical works" for my house. I will put this on my website when I get a chance. It is currently well over 100 pages!!!
Seeing that I had no certification for my installation, and the PIR label on my CU was blank, it was clear to me that I needed to do a PI. Having never done this before, this required a lot more research and preparation. Also I decided I needed a decent multifunction tester so I got my Robin off e-bay and then got it calibrated (another warning to those who want to do this - another not insignificant expense).
So I started to build the document. I started with some sections about the procedures I would follow for planning, design, testing etc. This included a statement about who will do it (me) and why I am competent. Here I included my academic and vocational qualifications in electrical/electronic engineering, and also my relevant electrical engineering work experience (all industrial). I also decided to mention that I am a Chartered Electrical Engineer and a corporate member of the IET (which I wouldn't be except for the fact that it is the only way for me to maintain my CEng status which I worked hard to get).
Next I added the results of my PI as a proper written report (including things like estimating the length of cable runs and comparing them with typical values of copper resistance per metre to the continuity measurements taken) and included the IET standard PIR. I also created a set of wiring diagrams as best I could.
By the time I had done this, I desperately needed to do some non-notifiable mods in the garage and loft. So I decided that I would follow a proper engineering design process for this. So I included written descriptions of things like requirements, planning (selection of materials, safe working etc), design (generally how I will meet the regs), installation (exactly what I did), test results & certification and validation.
The last section before I send this document to my LABC was a section on the 'major' works for my extenstion and other alterations. Here I primarily listed my requirements and what I wanted to do, and clearly defined which parts were notifiable. When I sent it to the LABC I directed them to read this section as the notification, and the use the rest of the document as demonstration of my competence.
The only reply I got was "so you're a competent person who is not registered with a self-certification scheme"? Which I confirmed.
That was a few months ago. Since then I have discussed a few issues with my LABC about fire protection, holes in joists etc, but we never discussed inspection. So since I am soon to change my CU, I thought I'd ask them about what they wanted to inspect. The answer was, as I have stated, that they will not inspect anything as they are happy that I have demonstrated my competence.
So that's it. Maybe there is some luck involved, but mainly it has been a lot of hard work on my part. Maybe my document is overkill, however as any other design engineer should agree, the act of writing things down and reviewing it does wonders for the design process, especially when it is done in phases.
Anyone who wants to follow should probably take most note of the fact that:
a) I can offer genuine qualifications (HNC & degree) to demonstrate my knowledge
b) I can offer electrical engineering work experience (including designing safety systems in the petrochem industry) to demonstrate related experience
c) I performed a full PI with test results and wiring diagrams, plus detailed information about work I had done to my installation as further evidence of my competence
d) I was able to convey all this to the LABC through the creation of my document, which was relatively easy for me because I have done countless similar documents during my experience as a design engineer
I hope this helps.