N.Y. Gen. Bus. Law § 204-a

§ 204-a. Safety chain latches required. Every person, firm or\ncorporation engaged in the business of furnishing public lodging\naccommodations in hotels, motels or motor courts shall install and\nmaintain, on the inside of each entrance door to every rental unit for\nwhich there is a duplicate or master key which would afford entry to\nsaid unit by one other than the occupant, a safety chain latch.\n