Ha - no it's a ground floor kitchen!
Emailed building control and had a response to one question direct from the horse's mouth
So, they won't tell me if this is a sensible thing to do unless I hand over the dosh.
Hi - Original builder moved to Australia. he did us a single storey extension 2006. It has a warm roof and felted (3 layers by a roofing company he brought in). Nice job, looks good! However, ever since we get a large area of pooling that sometimes covers over half the roof and sits for days...