Is it illegal to provide a place to have sex?

Some people are not able to have sex at home, and sometimes hotels are expensive. Would it be illegal to have a property that pay to rent for say, 1 hour to perform adult acts? Now I'm not saying prostitution, as the owner would not supply the call girls. Instead there would be an environment to have said relations. For instance: a lot of people would like to become part of the "Mile High Club," but dont want to risk the danger of getting arrested. So said owner provides a private craft, or helicopter to allow them to do so without risk. Is it illegal?