Approval of a preliminary OPD-H plan shall be by ordinance according to the procedures set forth in Chapter 1174, Amendments. Approval of the zoning of the land to an OPD-H district shall constitute approval of the preliminary plan. A preliminary OPD-H plan shall be valid for no more than 24 months, unless specifically provided otherwise in the OPD-H ordinance. If no building permit has been issued for the development within the 24 month period, the area of land to which the OPD-H ordinance applies shall be considered for possible rezoning by the City to remove the OPD-H designation.