Yes, I guess the insurance companies might ask for a certificate, but that's not quite the same thing as the law demanding one.
The part about a 30-day habitation limit was the response John received on the question of mobile homes. I would say if a council employee insists that part P applies to a mobile home, then he should be challenged.
Having read the appropriate statutory instruments, and received confirmation from my building dept. that a caravan (as per the 1960/68 Acts) is not officially a building, I would stand my ground.
