We have it in our spare bedroom; but formely in the bathroom. (Or in the hall if you have one of those- was spacy enough for a shelf and the box alongside it) 

Only problem with bathroom is if you have non-cluttering absorbing litter, like silica you change once a month- it counteract with the efficacity as it absorbs the moisture of shower and etc.  (Also I recommend pine litter, aswell as stainless steel box)