I am looking at purchasing a house that is in need of renovation.
OK.
So (presumably) that will include new circuits anyway.
And new sockets/lights/switches in new locations.
And possibly outside lighting and/or supplies.
And possibly garage/shed supplies.
etc etc.
You want all of that sorted out before you start plastering, papering, painting, flooring etc, so you need to think about where you'll want switches and sockets (it's difficult to have too many of the latter), 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.
Even though you don't (currently) live somewhere where supplies are dodgy in the winter I'm not sure that will be the case into the future, as we are going to start running out of capacity, so if you plan to stay in the house for a while you might think about having 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.
The point is that if you do a proper job of designing a refurbished installation you may find that there's going to be so much going on anyway that the issue of "does what's there need replacing?" pretty much goes away. In which case you might want to not spend money on an inspection.
If you can have electrical work done before you and furnishings, curtains etc, move in it will be cheaper - power tools can be used with more abandon, furniture doesn't have to be moved about, power doesn't need to be maintained/restored for the use by occupants, floorboards don't necessarily need to be replaced each night, and so on.
