A plan, or part thereof, which has been given final approval by the Borough Council shall be so certified without delay by the Borough Clerk and shall be filed of record forthwith by applicant in the Office of the County Clerk before any development shall take place in accordance therewith. Upon the filing of record of the plan, all other ordinances and subdivision regulations otherwise applicable to the land included in the plan shall cease to apply thereto. Pending completion within five years of the PRD or of that part thereof, as the case may be, that has been finally approved, no modification of the provisions of said plan, or part thereof as finally approved, shall be made nor shall it be impaired by act of the Borough except with the consent of the landowner.