Hi,

I'm having my 57yr old house fully rewired and have been told that to get a final sign-off by a certified electrician, the bathroom must have an extractor fan fitted to comply with the regs.
I understand that all new builds must have a fan fitted and also change-of-use rooms but wasn't aware the a re-wire of an existing bathroom would need it.
It has an opening window in it too.

True or false?

Gammy.

No need, although would be a good idea!  A separate switch is common the days.

While your rewire must comply with the building regs "part p", there is no need to comply with any other building regs regarding fans, or disabled access (part m, socket heights) etc.