Ohio Rev. Code Ann. § 303.023

Any planned-unit development regulations adopted in accordance with section 303.12 of the Revised Code, or any planned-unit developments constructed or approved in a preliminary or final form, under the provisions of a zoning resolution adopted prior to the effective date of this section, if otherwise lawful had they originated on that date, shall be deemed to have been lawful from their origin and the developments shall continue to be governed by regulations in effect at the time of approval, or as modified.