Think hard about where to have sockets - it's difficult to have too many, and also about what circuits to have. The items on the list below won't all apply to you, but they are worth thinking about:
- Upstairs sockets
- Downstairs sockets (or a L/R or front/rear split)
- Kitchen sockets
- Circuit for appliances
- Cooker circuit
- Non-RCD circuit for F/F
- Non-RCD circuit for CH boiler
- Dedicated circuit for hifi
- Dedicated circuit for IT equipment
- Upstairs lights
- Downstairs lights
- Lighting circuits with switches in the usual places but with 2A/5A round pin sockets at low level.
- Immersion heater
- Loft lights
- Shower
- Bathroom circuit
- Alarms
- Supply for outside lights
- Supply for garden electrics
- Supply for shed/garage
Plus any peculiarities brought about by your house layout & construction - e.g. in mine because of solid floors and where the socket circuits run, I have a radial just for a socket in the hall, the doorbell and the porch lights.
Unless you want to go to the expense of RCBOs throughout, the CU should have at least 3 sections, 2 on RCDs and one not into which you can install a mix of RCBOs and MCBs.
It can be a good idea to put all wiring in conduit for ease of future changes. And if you specify metal conduit for switch drops, or BS 8436 cable it removes the need to have RCDs where you'd rather not.
If you live somewhere where supplies are dodgy in the winter, have the lights, the boiler supply, and a socket in each room wired to a separate CU, or a separate section in a large one, that can be supplied by an emergency generator - lights, heating, TV and a kettle/microwave make life a lot more bearable.
Flood-wiring with
Cat6 or Cat6a cable is worth thinking about.
As ever, personal recommendations are always the best way to find a reputable tradesman, but if you're having to go ahead without much in the way of those, or references, don't put any store by registration itself - sadly it is possible to become registered with woefully inadequate qualifications and zero practical experience. You don't have to spend long here to see people cropping up who are registered and "qualified", but who are clearly seriously incompetent in reality and who should not be charging for their services.
If you are looking for someone to rewire a house, it may surprise and dismay you to learn that it is quite possible to become a "certified electrician" without ever having done that before, and without having acquired any of the practical skills needed to do it without half-destroying your house in the process.
It's your money, possibly £'000s of it, and you have every right to ask prospective tradesmen what their qualifications and experience are.
Just being listed here is not a good enough guide. No genuinely experienced electrician, with the "full set" of C&G qualifications will mind you asking - in fact he will wish that everyone was like you.
I feel sorry for people who have been misled by training organisations and (shamefully) the Competent Person scheme organisers into thinking that a 5-day training course, a couple of trivial examples of their work and some basic understanding of how to use test equipment will make them an electrician, but not sorry enough to agree with them trying to sell their services to Joe Public.