The
Council on Tall Buildings and Urban Habitat created the definition for measuring building heights. Antenna don't count but spires do.
"HEIGHT: The height of a building is measured from the sidewalk level of the main entrance to the structural top of the building. This includes spires, but does not include television antennas, radio antennas, or flag poles. Height is listed in both meters and feet and is rounded to the nearest integer. This is the official criterion used by the Council in determining ranking."
This was set years ago.