In the case of final site plan approvals, subdivisions, and associated variances given in connection therewith, if the property owner, applicant, or developer does not obtain building permits, or substantially act thereupon expeditiously, or start and proceed with construction, or fails to use its best efforts to conclude the project, or fails to adhere to a phasing plan set forth in a developer’s agreement, or any extensions thereof, provided and given by the Borough of Wanaque, then and in that event such approvals, subdivisions, and variance shall be considered stale and shall be void and vacated.