Story County, IA Building Setbacks & Zoning: Setback Rules (2026)

07, sets the bulk requirements for every use permitted in the R-1 Transitional Residential District, the county's district for lower-density rural residential subdivision. A single-family dwelling served by a private well and septic system needs a minimum net lot area of 25,000 square feet, a 40-foot front setback, a 10-foot side setback, a 25-foot side setback on a corner lot, a 20-foot flag lot yard setback, a 35-foot rear setback and a 90-foot minimum lot width. The same dwelling type served by a common water or sewer system needs less lot area (10,000 square feet) and a shorter 30-foot front setback, though the side, corner, flag and rear figures stay the same and the minimum lot width drops to 80 feet.

Other permitted uses in the district carry a 35-foot front setback on both private and common systems. Accessory structures must match the front and side setbacks required for the principal use, keep 25 feet from a corner lot line, and sit at least 2 feet from a rear line (5 feet where the accessory structure sits along an alley). Conditional uses inside the district, listed in Chapter 90, must additionally meet the external separation standards of Chapter 86 and the Table 86-5 yard requirements unless the Board of Adjustment sets a different standard. 11 is required before construction begins.