The district regulations hereinafter set forth in this section qualify or supplement, as the case may be, the district regulations contained in this chapter. The Zoning Board of Adjustment may grant variances after public hearing as specified in the Code of Iowa and exceptions to the following:

1.   Height Exceptions and Variations.

   A.   Public and semi-public service buildings, hospitals, institutions, or schools, may be erected to a height not exceeding 75 feet, unless it is set back one additional foot from all required yard lines for each foot of additional height above the height limit in the district in which the building is located.

   B.   Single-family and two-family dwellings may be increased in height by not more than 10 feet. If the side yard and the rear yard is increased by not less than 10 feet in addition to the required yard setbacks, they shall not exceed three stories in height.

   C.   Chimneys, cooling towers, elevator bulkheads, fire towers, monuments, stacks, stage towers, scenery lofts, tanks, water towers, ornamental towers and spires, church steeples, radio towers, or necessary mechanical appurtenances may be erected to a height in accordance with this Code of Ordinances.

   D.   No building exceeding two and one-half stories or 35 feet shall be erected within 750 feet of any airport, land field, or landing strip, except for accessory buildings or structures related to the operation of the airport, landing field or landing strip.

   E.   Buildings that are to be used for storage purposes only may exceed the maximum number of stories that are permitted in the district in which they are located, but such buildings shall not exceed the number of feet of building height permitted in such district.

2.   Area Exceptions and Variations.

   A.   Every part of a required yard shall be open to the sky, unobstructed, except for accessory buildings in a rear yard, and except for the ordinary projections of sills, belt courses, cornices and ornamental features projecting not to exceed 12 inches.

   B.   Open or lattice-enclosed fire escapes, fireproof outside stairways, balconies opening upon fire towers projecting into a rear yard not more than five feet, and the ordinary projections of chimneys and flues into the rear yard may be permitted by the Zoning Administrator.

   C.   For the purpose of the side yard regulations, a two-family, a group house, or a multiple dwelling shall be considered as one building occupying one lot.

   D.   More than one industrial, commercial, multiple dwelling, or institutional building may be erected upon a single lot or parcel, but the yards and open spaces required around the boundaries of the parcel shall not be encroached upon by any such buildings, nor shall there be any change in the intensity of use regulation.

3.   Temporary Buildings. Temporary buildings that are used in conjunction with construction work only, may be permitted in any district during the period that the building is being constructed, but such temporary buildings shall be removed upon completion of the construction work as determined by the Building Official.