There are definitely more than two possibilities: - The condo rules or the co-op lease forbids rentals for less than a month, in which case the owner is in vio

There are definitely more than two possibilities: - The condo rules or the co-op lease forbids rentals for less than a month, in which case the owner is in violation of his lease or agreement. - The apartment is in a jurisdiction which holds short term rentals illegal, and the owner is breaking the law. Regardless of the level of the noise.