§ 81-f. Planned unit development zoning districts. A city legislative body, except in a city having a population of more than one million persons, is hereby authorized to enact, as part of its zoning local law or ordinance, procedures and requirements for the establishment and mapping of planned unit development zoning districts. Planned unit development district regulations are intended to provide for residential, commercial, industrial or other land uses, or a mix thereof, in which economies of scale, creative architectural or planning concepts and open space preservation may be achieved by a developer in furtherance of the city comprehensive plan and zoning local law or ordinance.