I'm not sure I would get much of a workout in if I was crying non stop. The idea of unused space makes me think of a store in the town I grew up. A couple of years ago they found a lady living in the canopy of the store. She had a fully furnished apartment up there. Apparently she had been living there for quite some time and no one knew. It was pretty crazy. Like back behind the Family Fare part.
RE: A Geeky Guy's Guide to Secret mall Apartment (Spiler alert, it is beautiful!)