When to go for a full re wire?

[Markbon]

Hello, I'm going to be having a fair bit of electrical work done as were doing an extension. Theres another room downstairs that needs rewiring. Upstairs theres a bedroom thats becoming a bathroom so that needs doing.
So theres a room downstairs and 2 upstairs that have obviously been rewired and seem ok but are black and red wires.
We probably need about 60-70 percent doing so should I get quotes for getting the lot done?
If so would that include the lights which was also done probably about 20 yrs ago and seem fine but id like downlights in some rooms.
Cheers

 

[AndyPRK]

Doesn’t sound like the lights need doing.
Best to seek advise from the electrican quoting for the rest. And go off test results

 

[ericmark]

1966 is the date that matters, before 1966 often no earth to lights and can find rubber cables, after 1966 PVC or better cables and all circuits earthed, there is an exception there was at one point some aluminium cable used, and there has been some batches of PVC cable where the plastersizer leached out making the insulation brittle, and of course people can use wrong overload devices and over load the cable.

However in the main a house wired post 1966 does not need rewiring, it may need the consumer unit upgrading to give RCD and SPD protection. But wiring should be sound.