Up until April 26, 2019, short-term vacation rentals (like Airbnb, VRBO, HomeAway, etc.) were probably allowed in zoning districts where single family homes are permitted. In April, the Pennsylvania Supreme Court decided that a short-term vacation rentals are not permitted as a single family use.
What do municipalities do now?
First, we should review how the Courts got to this point. It is an interesting development. The first case (Marchenko) dealt with a homeowner who rented her home for less than 25% of the year. The second case (Shvekh) had homeowners who rented their home for about half the year. The third case (Slice of Life) has an owner who bought the property solely as an investment, and never lived there at all. The Commonwealth Court said the first was OK, and then the next two cases built on that decision.