165A.23   PERMITTED MODIFICATIONS OF HEIGHT REGULATIONS.
   1.   The height limitations of this Zoning Code shall not apply to:
      Air pollution prevention devices
      Belfries
      Chimneys
      Church spires
      Commercial elevator penthouses
      Conveyors
      Cooling towers
      Domes
      Elevator bulkheads
      Fire towers
      Flag poles
      Grain elevators
      Observation towers
      Ornamental towers, cupolas and spires
      Public and semi-public buildings including hospitals, churches, sanitariums, schools and water reservoir towers
      Public monuments
      Radio or television towers less than 125 feet tall
      Silos
      Smoke stacks
      Stage towers or scenery lots
      Storage towers
      Tanks
      Water towers and standpipes
      Web cameras and meteorological equipment
   2.   Exceptions to the height restrictions shall not be granted in cases where they would violate height restrictions of the aircraft approach and turning zone.
   3.   Any of the above except flagpoles and chimneys, when located in any zoning district and with a height limit of 45 feet or less, shall be allowed only upon finding of the Board of Adjustment that the appurtenances will not be unduly detrimental to the surrounding property.
   4.   When permitted in a district, public or semi-public service buildings, hospitals, institutions, or schools may be erected to a height not exceeding 75 feet when each required yard line is increased by at least one foot for each one foot of additional building height above the height regulations for the district in which the building is located.