Rock Island County, IL Building Setbacks & Zoning: Setback Rules (2026)

175 of the Rock Island County Code of Ordinances sets out the lot area and yard table for the R-1 Single-Family Dwelling District. For a one- to one-and-a-half story house on a 7,500-square-foot, 75-foot-wide lot served by central sewer, the minimums are a 25-foot front yard depth, an 8-foot least side yard width, a 30-foot combined side yard sum, and a 35-foot rear yard depth. A two- to two-and-a-half story house on the same size lot needs a wider 10-foot least side yard and a 25-foot side yard sum, with the same 25-foot front and 35-foot rear yards.

Where a lot is not served by a central or municipal sewerage system, the minimum lot area jumps to 20,000 square feet with 100 feet of width, and the front yard depth increases to 40 feet, with a 15-foot least side yard, 30-foot side yard sum, and 40-foot rear yard, regardless of the number of stories. 076 layers on supplemental rules: no side yard may be less than three feet wide unless the Zoning Board of Appeals authorizes an exception, and on corner lots the required front yard setback applies along both intersecting streets.

073 exempts small building elements from the front yard line, including bay windows and balconies occupying no more than one-third of the front wall, and uncovered porches, chimneys, and similar features that stay at least five feet from every lot line and no more than three feet above the average finished grade. These are unincorporated-county standards only; Rock Island, Moline, and other cities inside the county apply their own zoning setback tables.