Boone County, IN Building Setbacks & Zoning: Setback Rules (2026)

Boone County Code § 157.007(B), Table 3 (Residential Uses and Requirements, Single Family), fixes yard setbacks that apply across the AG, RE, R1, R2, R3, R4, LB, U5, GB, FS and A5 districts. The front yard minimum is 20 feet in all districts, though flag lots are exempt from that rule. The rear yard minimum for a primary structure is 20 feet, dropping to just 5 feet for an accessory structure. The side yard minimum is 5 feet in all districts except the Agricultural District, where a wider spacing rule instead requires 140 feet of minimum spacing between dwellings.

Table 3 also carries a road-frontage minimum of 45 feet, with up to 20% of the lots in a subdivision allowed to reduce that frontage by up to 20%. Multi-family and mobile-home development get separate figures under Table 4 and Table 5: a 20-foot front yard and a 10-foot side/rear yard for two-family and multi-family dwellings, and the same 20-foot front, 10-foot side/rear pattern for mobile home parks. Section 157.027 (YARDS) then layers general rules on top of the tables: architectural features like cornices and chimneys may project up to 2 feet into a required side or rear yard and up to 3 feet into a front yard; corner lots must observe two front-yard and two side-yard setbacks because every street-facing property line counts as a front line; and where recorded subdivision plats already establish front setback lines, those lines govern so long as they are not shorter than the district's required front yard.

Enforcement of the zoning chapter runs through the Boone County Area Plan Commission and its Director, who issue improvement location permits, and violations of Chapter 157 fall under the county's general penalty, § 10.99, of up to $2,500 for a first offense and up to $7,500 for repeat offenses.