If the developer wishes to install his improvements before the subdivision plat is approved by the Commission or is recorded, he shall comply with the requirements of both the preliminary plan approved by the Commission and the proposed subdivision plat. Certification by an engineer that the improvements have been built to plans and specifications which have been filed with and approved by the Director of Public Safety and Service prior to any construction, however, shall be required. (Ord. 74-76. Passed 9-13-76.)