The planning commission is authorized to render a final decision of approval or disapproval for an application for a planned unit development. In addition, the planning commission may attach such conditions as it may deem necessary to ensure compliance with the purposes set forth in section 8-8-2 of this chapter. If approved, the proposed planned unit development has met the subdivision preliminary approval and then may proceed to development in accordance with the county subdivision ordinance, using the same criteria as final plat approval. (1998 Code § 17.56.060)