11-1-5: SETBACK REQUIREMENTS; BLOCKS:
   A.   Front Yard:
      1.   Less Than Twenty Five Percent Built On: In a block in the residential or multiple dwelling districts in which less than twenty five percent (25%) of the total number of lots have permanent buildings erected upon them, no building shall be erected which is set back from the front lot lines less than a distance equal to thirty percent (30%) of the depth of the lot.
      2.   More Than Twenty Five Percent Built On: If more than twenty five percent (25%) of the lots in a block are built upon, no building shall be erected which is set back from the front lot line less than a distance which shall be the average of the setback observed by the adjoining houses on either side.
      3.   Definition: Reference to a "block" in this subsection shall be construed to mean any one side of a street between two (2) intersecting streets. (1982 Code § 9.317)
   B.   Rear Yard:
      1.   Buildings Less Than Two And One-Half Stories: In the residential and multiple-dwelling districts, every building two and one-half (21/2) stories or less in height shall have a rear yard of not less than twenty percent (20%) of the depth of the lot.
      2.   Buildings Greater Than Two And One-Half Stories: Every building greater than two and one-half (21/2) stories in height shall have a rear yard of not less than twenty five percent (25%) of the depth of the lot.
      3.   Corner Lot: In the case of a corner lot, the above requirements shall be construed to require a setback from the street lines on those sides of such lot upon which adjoining buildings front or upon which lots have been platted; provided, that the buildable width of such lot shall not be reduced to less than sixty percent (60%) of the width of the lot. (1982 Code § 9.318)
   C.   Side Yards:
      1.   Buildings Less Than Two And One-Half Stories: In the residential and multiple dwelling districts, every building two and one-half (21/2) stories or less in height shall have two (2) side yards, one being not less than ten percent (10%) of the lot width and the other being not less than fifteen percent (15%) of the lot width.
      2.   Buildings More Than Two And One-Half Stories: Every building greater than two and one-half (21/2) stories in height shall have two (2) side yards of not less than twenty five feet (25') each.
      3.   Public And Semipublic Buildings: Notwithstanding subsections C1 and C2 of this section, in the case of public and semipublic buildings such as schools, churches, libraries, etc., in the residential and multiple dwelling districts, such buildings shall have two (2) side yards of not less than twenty five feet (25') each. (1982 Code § 9.319)
   D.   Unplatted Tracts: All buildings on masonry foundations hereafter erected on unplatted tracts adjoining any platted part of the city shall conform to the setback provisions by extending the setback lines of the adjoining platted property. (1982 Code § 9.322)