I know v little about these and just want to ask someone who does know. A close friend of mine took one out about 4 years ago on a flat in London. She has another house elsewhere and she got the BTL to actually live in M to Fri for work and has never let it out. So in effect she lives there. The mortgage was calculated on potential rental as she couldn't have got a residential mortgage as she has one to her max on her other house. Is this allowed can you get one of these mortgages and then live in it? I think its a dangerous strategy but she says as long as she makes the payments it doesn't matter!