Completion of Planned Developments Required within Two Years. All previously approved planned developments which have not been fully constructed and completed in accordance with the terms and conditions of approval under the provisions of its enacting ordinance, site plan, and program shall be fully completed and constructed in accordance with those terms, conditions, and provisions within two years of the effective date of the ordinance codified in this title. Failure to so complete any previously approved plan development shall constitute a forfeiture of all rights, privileges, and approvals pertaining to said planned development. Such time may be extended for a maximum of one year by the planning commission for good cause not within the control of the applicant, developer, or owner of said planned development. Upon any forfeiture under the provisions of this subsection, all further development, including the use or occupancy of any land or structure, or the completion of any structure, is subject to full compliance with the terms and provisions of this title.