We have a similar unit -- small, one bedroom/one bathroom, one parking space, in a detached building in our backyard. It does seem best suited for one person because of the one parking space and a combination of a tiny kitchen/living area and large bedroom suite. We've never advertised it for one vs two people, and honestly, if a nice, mustachian couple wanted to save some money and share it, I'd be OK with that. I'm not really sure why you think two people would necessarily be "more wear and tear" than one? Anyways, for our place, we've never advertised it to any group or for anyone in particular, but in 5 years, we've only had singles seriously interested. We HAVE had more turnover on this place because everyone moves out when they find a significant other (although two of those tenants relocated to other cities). So, putting aside discrimination laws, I'd reexamine the pros and cons of couples vs singles-- couples may (or may not) keep the place cleaner, have fewer groups of people over, and be less transient. On the other hand, I always see couples as more likely to ask permission to get a dog, which is more wear and tear.