Why does the project have to be reverted to the local Authority?
Only local authorities have the powers to take action should, for whatever reason, the Approved Inspector be unable to comply with the building regulations.
In general only if work has not started can another Approved Inspector submit a new initial notice to allow them to carry out the building control function.
There is one exception – which is where the original Approved Inspector has issued a part final certificate for work completed – for example for the foundations.
In this case the rest of the building control work could be transferred to another Approved Inspector, but only if the the part final certificate was issued by the original Approved Inspector while it had the required insurance.
Looking for information on what to do if your private building control inspector doesn't have PI insurance?