The height limitations of this chapter shall not apply to church
spires, belfries, cupolas, and domes not used for human occupancy;
nor to chimneys, ventilators, skylights, water tanks, fire towers,
bulkheads, and similar features; nor to silos and other farm buildings
and structures; not to any accessory mechanical appurtenances usually
carried above the roof level.
The provisions of this chapter shall not apply to prevent the
erection above the building height limit of a parapet wall or cornice
for ornament (and without windows) extending above such height limit
not more than five feet.