In the C-1, C-2, O-R-D, HV and R-M zones, penthouse or roof structures for the housing of elevators, stairways, tanks, ventilating fans or similar equipment required to operate and maintain the building, and fire or parapet walls, skylights, architectural feature towers, steeples, flagpoles, chimneys, wireless or television aerials, theater lofts, or similar structures, may be erected a maximum of eight feet (8') above the height limits prescribed in this title, and provided the protrusion meets the graduated height requirement. No space above the height limit shall be allowed for the purpose of providing additional floor space. (Ord. 2014-15, 8-21-2014)