In reply to Steve Perry:
I'd stake my life that there is no definitive list that covers every bothy, howff and estate out building! I've seen quite a few lists of buildings, shelters etc that various bodies groups and website have tried to setup, but even comparing those they all have different ones included and not. Closest I can recall was a list of every building shown on an OS map, but this didn't differentiate between bothy or useless, now collapsed, building. Could be the one that John is referring to above. But I don't recall it having too many details (whether kept open of not, private building or derelict etc). I suspect that by their nature the estate bothies are too random in whether or not they are unlocked, knocked down, turned to sheds / livestock shelters for a list to be all that much use anyway.
Friends and I have between us spent a lot of time googling and searching online for info on various building shown on maps (sad as that is), particularly in the NW - if a definitive list with every howff, bothy and building existed we would have found it, in fact I'm certain that if it did exist it would be well known online given how often folk are looking for just that kind of info. If there is a definitive list though, I'm happy to be corrected (and take advantage!)
the freebothies site linked to above is a good resource, as is
http://www.geograph.org.uk/ for a bit of investigating.
Cheers,
Stuart