If an application is denied by the City Planning Department and no appeal is filed, or if upon review or appeal the denial is affirmed, no new request for the same or substantially similar proposal shall be filed within six (6) months after the date of final decision denying the application. An application may be denied without prejudice and with a waiver of the six (6) month restriction. If a waiver is not granted upon denial and conditions have changed to an extent that further consideration of an application is warranted, the hearing body, on its own motion, may consider new evidence and waive the six (6) month restriction.