The final Development Plans shall conform to the approved Preliminary Development Plans, shall be in final form for the issuance of a building permit, shall have been previously approved by the City Administrator and the City Engineer, and shall include a construction schedule of development. It shall be submitted to the Planning Commission at least seven (7) days before the scheduled meeting for approval and recommendation to the Governing Body. A final approval by the Governing Body shall authorize construction to begin. Any land reserved for public use (utility easements, streets, drives, ways, etc.) shall be processed and approved in accordance with the rules and regulations for platting contained in the "Subdivision Regulations for Tonganoxie, Kansas". Construction of a least the first stage of development shall begin within eighteen (18) months from the date the ordinance of the zoning change was published in the paper. If construction does not begin within this period and no effort is made of an extension of time by the owner, the Planning Commission shall recommend to the City Commission that the ordinance should be voided, and when voided said property shall revert back to its original zoning district.