The following structures, except where preempted by other government regulations, shall not be subject to the height limitations of the districts in which they are located:
A. Farm buildings and structures.
B. Aerials, antennas, belfries, chimneys, cupolas, domes, elevators, penthouses, flagpoles, masts, monitors, smokestacks, spires, towers (cooling, fire hose), and ventilators; provided, that they are not intended for human occupancy. (1991 Code § 16-12-220)