kevin_robson said:
a) if I replace a bathroom suite and hence the earth bonding whether it needs testing
All electrical work should be tested.
In this case, however, you are not changing the bonding arrangement, merely transferring it to your new bathroom suite. I would not notify it.
b) If I put GU10 spotlights in a bathroom it needs testing.
All electrical work should be tested.
If you replace a fitting like-for-like (call it maintenance) then, as above, I wouldn't notify it. However, replacing an existing light for several lights is extending a circuit in a special location (the bathroom). It should be tested, certified and notified to building control.
c) If I put in warmup underfloor heating in a bathroom this would need sighning off, if I was adding into an existing RCD protected ring
In this case you are materially changing the electrical installation in your bathroom. It needs to be tested, certified and notified.
An electrician
should issue an installation certificate for
any work carried out (with the reasonable exception of a like-for-like swap). This has nothing to do with Part P, but it is required (and has been for many, many years) by BS 7671 The Wiring Regulations.
For notifiable work you have two options (three if you use a third-party building control firm, but this is not normal for householders.):
1. Notify local authority building control in advance, pay their fee and follow their guidance as to what they want from you. LABC's enforce the regs locally and have a degree of leeway in how they ensure compliance.
Or,
2. Employ an electrician registered with a 'competent persons scheme'. He will do the work, issue you a BS 7671 certificate, then notify (if necessary) his registration body who will inform building control and send you a building regulations completion certificate.
That's it.