Projections Above Height Limits. Unless otherwise specified in this code, flues, chimneys, antennas, elevators or other mechanical equipment, utility, or mechanical features may exceed the height limit of the base district by not more than 15 feet, provided such feature shall not be used for habitable space and appropriate screening is provided, as determined by the Director. Architectural appurtenances to churches and other religious institutions involving a steeple, or cross, or combination thereof, and clock towers and similar design elements on commercial structures, may exceed the maximum height of the base district if it is determined through the development review permit or conditional use permit process that architectural compatibility and appropriate building scale are achieved and maintained.