"If you live in accommodation that you do not own, it will not count in determining whether you are purchasing an additional residential property. If you do not own any other property, then the higher rates of SDLT do not apply."
AR does not own any of the house in Ashton. She might live there more days of the year than she intends to in Hove or in the Admiralty flat, but she doesn't "own" it, so if she had been asked if she owned any other property when she signed the deeds to buy the Hove flat, she could honestly have said "no".