On a purely practical note, I once spoke to a very experienced local agricultural estate agent who said he'd never met a farmer who'd developed outbuildings to residential use who hadn't bitterly regretted it a few years later, mainly because you can't control who buys it and you can find yourself sharing space with some very unpleasant people. We converted a stone barn which was already a shop/tearoom when we arrived here, but only to holiday cottage use. Most guests are OK, some really nice and others we can't wait to see the back of (a bit like life, really!) We always give a big sigh of relief at the beginning of the January/February closed season. At least they only stay for a week at a time.