No building or structure shall be erected in any zone in excess of 2 1/2 stories or 35 feet in height except as provided in this section or unless otherwise indicated in the applicable zone, in which case the district requirements shall apply.

Industrial buildings or structures shall not exceed a maximum of three stories nor a height of 45 feet.

The height limitations of this chapter shall not apply to church spires, belfries, cupolas, chimneys, ventilators, skylights, water tanks, silos, necessary mechanical appurtenances usually carried above the roof level, such as elevator housings, nor to noncommercial radio and television antenna, except where in the opinion of the Land Use Board such may be deemed to interfere with aerial navigation or constitute a fire hazard. Roof structures for the housing of stairways, tanks, ventilating fans, air-conditioning equipment or similar equipment required to operate and maintain the building may be erected above the height limits prescribed by this subsection, but in no case cover more than 10% of the roof area nor exceed the maximum height permitted in the district by more than 10 feet. These items shall be shielded by a parapet wall or other architectural relief consistent with the architecture of the main structure.