(a) Height. The district height limitations stipulated elsewhere in this Chapter may be exceeded, but such modification shall be in accord with the following:
(1) Architectural Structures. Agricultural structures, such as barns, silos and windmills, shall not exceed in height twice their distance from the nearest lot line.
(2) Special Structures, such as elevator penthouses, gas tanks, grain elevators, scenery lots, radio and television receiving antennas, manufacturing equipment and necessary mechanical appurtenances, cooling towers, fire towers, substations and smoke stacks, are exempt from the height limitations of this Chapter.
(3) Essential Services, utilities, water towers, electric power and communication transmission lines are exempt from the height limitations of this Chapter.
(4) Communication Structures, such as radio and television transmission and relay towers, aerials and observation towers, shall not exceed in height three (3) times their distance from the nearest lot line.
(5) Public or Semipublic Facilities. Public or semipublic facilities, such as schools, churches, hospitals, monuments, sanitariums, libraries, government offices and stations, may be erected to a height of sixty (60) feet, provided all required yards are increased not less than one (1) foot for each foot the structure exceeds the district's maximum height requirement.
(b) Yards. The yard requirements stipulated elsewhere in this Chapter may be modified as follows:
(1) Architectural Projections. Chimneys, flues, sills, eaves, belt courses, ornaments, etc., may project into any required yard, but such projection shall not exceed two (2) feet.
(2) Essential Services, utilities, electric power and communication transmission lines are exempt from the yard and distance requirements of this Chapter.
(3) Landscaping and Vegetation are exempt from the yard requirements of this Chapter.
(c) Average Building Setbacks. In Residential and Business Districts, except for corner lots, required setbacks shall be modified in the following cases:
(1) Average Front Yards. The required front yards may be decreased in any residential or business district to the average of the existing street yards of the abutting principal structures on each side. Where fifty percent (50%) or more of the frontage on a block is occupied by principal structures having setbacks less than that required by this Chapter, setback on each remaining lot shall be determined in accordance with the following rule. The front building line of a proposed structure shall be no nearer the front lot line than a line joining adjacent front corners of the nearest principal struc- tures which are in the same block frontage on either side of the proposed structure. If, on a block frontage, no principal structure exists to one side of a proposed structure, a structure may be assumed to exist on the comer lot which conforms to the minimum setback and side yard width requirements of this Chapter.
(2) Additions. Additions in the front yard of existing structures shall not project beyond the average of the existing front yards on the abutting lots or parcels.
(d) Corner Side Yards. The required side yard on the street side of comer lots shall be at least twenty-five (25) feet on each side.