If you're thinking of doing this but aren't sure about the legal side of things, consider buying a duplex or quadplex and living in one of the units yourself.

If you're thinking of doing this but aren't sure about the legal side of things, consider buying a duplex or quadplex and living in one of the units yourself. This will let you qualify for owner-occupied rates on the mortgage and insurance, likely insulate you from a condo agreement which would forbid renting, and means that you're the primary party who'd suffer from guest misbehavior, which strikes me as socially optimal. Also, if you tire of Airbnb transient relationships, duplex units are fairly easy to rent out "traditionally." Downside: more capitally intensive, and requires you to be OK with owning a house. This is (pre-Airbnb) one of the classic hacks for middle class Americans to start real estate businesses, since you can fairly easily get sufficient cash flow and/or equity after running a duplex for a few years to get a bank to OK you adding other rental properties.