The district height limitations stipulated elsewhere in this chapter may be exceeded, but such modification shall be in accordance with the following:
A. 
Architectural projections. Architectural projections such as spires, belfries, parapet walls, cupolas, domes, flues and chimneys are exempt from the height limitations of this chapter.
B. 
Special structure height limitations. Special structures such as elevator penthouses, gas tanks, grain elevators, scenery lofts, 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.
C. 
Essential services height limitations. Essential services, utilities, water towers, electric power and communication transmission lines are exempt from the height limitations of this chapter.
D. 
Communications structures height restrictions. Communications structures such as radio and television transmission and relay towers, aerials and observation towers shall not exceed in height three times their distance from the nearest lot line.
E. 
Agricultural structures height restrictions. Agricultural structures such as barns, silos and windmills shall not exceed in height twice their distance from the nearest lot line.
F. 
Public facilities height restrictions. Public or semipublic facilities such as schools, churches, hospitals, monuments, sanitariums, libraries, governmental offices and stations may be erected to a height of 60 feet, provided all required yards are increased not less than one foot for each foot the structure exceeds the district's maximum height requirement.
The yard requirements stipulated elsewhere in this chapter may be modified as follows:
A. 
Uncovered stair restrictions. Uncovered stairs, landings and fire escapes may project into any yard, but not to exceed six feet and not closer than three feet to any lot line, and must be eight feet or more above ground.
B. 
Architectural projection restrictions. Architectural projections such as chimneys, flues, sills, eaves, belt courses and ornaments may project into any required yard, but such projection shall not exceed two feet.
C. 
Cul-de-sac and curve restrictions. Residential lot frontage on culs-de-sac and curves may be less than 80 feet, provided the width at the building setback line is at least 80 feet and the street frontage is no less than 45 feet.
D. 
Residential fence restrictions. Residential fences are permitted on the property lines in residential districts, but shall not, in any case, exceed a height of six feet, and shall not exceed a height of four feet in any street yard. The finished side of the fence shall face the adjoining lot.
E. 
Security fence restrictions. Security fences are permitted on the property lines in all districts, but shall not exceed 10 feet in height and shall be an open type similar to woven wire or wrought iron fencing.
F. 
Accessory uses and structures restrictions. Accessory uses and detached accessory structures are permitted in the rear yard only, shall not be closer than 10 feet to the principal structure, shall not exceed 35 feet in height, shall not occupy more than 20% of the rear yard area, and shall not be closer than eight feet to any lot line nor five feet to any alley line.
[Amended 11-13-2012 by Ord. No. 12-5]
G. 
Essential services exemptions. Essential services, utilities, electric power and communication transmission lines are exempt from the yard and distance requirements of this chapter.
H. 
Street yard restrictions. The required street yards may be decreased in any residential or business district to the average of the existing street yards of the abutting structures on each side, but in no case less than 15 feet in any residential district and five feet in any business district.
Sirens, whistles and bells which are maintained and utilized solely to serve a public purpose are exempt from the sound level standards of this chapter.
Where the setback of existing structures deviates from the required district setback, new structures shall be set back the average distance.