The Research Department evaluates proposals for landmark designations and is responsible for preparing information on all buildings and neighborhoods considered by the Landmarks Preservation Commission as potential landmarks. The department evaluates buildings and neighborhoods from all five boroughs representing a wide variety of eras, styles, materials, and purposes. Designated landmarks must be at least thirty years old and have architectural, cultural or historical significance.  The Commission’s designations include individual buildings, publicly-accessible interiors, publicly-owned landscapes, and areas of the city that qualify as historic districts because of their special character and/or historical or aesthetic interest.  Anyone may submit a request for the Commission to evaluate a property as an individual landmark or an area of the city as a potential historic district. It is the responsibility of the Research Department to conduct research and assess the significance of these resources in order to recommend whether or not proposed sites meet the criteria for landmark designation. The department presents this research to the commission staff and to the commissioners.