This calculation does not include architectural features, church spires, chimneys, flagpoles, antennas, and weather vanes. Also, this calculation does not include roof-mounted solar energy systems, plumbing, electrical, heating, ventilating and air-conditioning mechanical equipment, provided that it does not exceed four feet from the highest point of the roof where it is located. Finally, this calculation does not include that portion of a building necessary to accommodate an elevator overrun, provided that it does not exceed four feet from the highest point of the roof where it is located.