MDL § 4 — Class A 30-Day Rule

N.Y. Mult. Dwell. Law § 4(8)(a), (9)

N.Y. Multiple Dwelling Law § 4(8)(a) defines a Class A multiple dwelling as one occupied for "permanent residence purposes" — occupancy of a dwelling unit by the same natural person or family for thirty consecutive days or more — and provides that a Class A dwelling shall only be used for such purposes. It carves out two exceptions that are not deemed inconsistent with permanent-residence use: occupancy under thirty days by house guests or lawful boarders living within the permanent occupant's household, and incidental, uncompensated occupancy under thirty days while the permanent occupants are temporarily absent. Subdivision 9 separately defines Class B multiple dwellings (hotels, lodging houses, rooming houses, boarding houses) as transient abodes; these definitions, with the thirty-day language added by Chapter 225 of the Laws of 2010, are a key statutory basis for New York City's restriction on entire-unit short-term rentals.