Does a bathroom have to be fully fitted before the building control guy can issue a certificate

First I've heard heard of this. Have you asked building control for there reasons why ? If that's what they're asking for then you have to comply.

If an extension contains a space that has tapped into services, in this case the mains sewer requires completion under building control

No, absolutely not. Building Regs / Inspector rarely have much to do with bathrooms. If they are requested then their job is much more ‘architectural’ - any walls out / U Beams in? After that; safe water / electrical fittings and especially ‘waste’. It must be one of the easiest inspections and approval going in the Home Improvement business. Your bathroom does NOT have to be 100% completed before inspection. * Any building issues * Water / Electrics * Waste I hope this helps. interior[DESIGN{

Everything things have to be completed before you call inspector for certificate. With my own experience and knowledge I have completed extention with bathroom but I have no connected extractor fan to the power because costumer want to change for timer. Inspector do not pass .when we install new He come again and check swich if working correctly. Then passed and give certificate. Thank you

Hello There is no need for building control to see the finished result. However if you are letting the property out or it is an "HMO", then Tey need to make sure all complies.