Penthouses or roof structures for the housing of elevators, stairways, tanks, ventilating fans or similar equipment required to operate and maintain a building, skylights, towers, steeples, flagpoles, chimneys, wireless masts, water tanks, silos or similar structures may be erected above the height limits herein specified if so approved by the Project Review Committee. The Project Review Committee shall not approve the structures if they determine that these structures may pose health, safety, or welfare risks to surrounding property. No penthouse or roof structure or any space above the height limit shall be allowed for the purpose of providing additional floor space.
(`94 Code, App. C, Art. VI, § 13)