If he's only this way about the condo, I'd imagine he was very attached to the condo and had mixed feelings about actually ever renting it out. He may just like these sorts of tasks too and not have anywhere else in his life he can do projects like this, nowhere he has such a large "artist's pallet". Sounds like he does it by himself also? That would be a wonderful time to think and be quiet within one's self, just commune with "nature" so-to-speak? Some people read or go for walks, take bubble baths or veg in front of the TV but sounds like this guy gets his relaxation oiling screws :-) I'd leave him be if he himself is not bothered by it.