Ada County, ID Building Setbacks & Zoning: Setback Rules (2026)

Ada County Code Section 8-10-2 defines setback generally as the minimum required distance between the property line and the nearest structure, then breaks it into front, interior side, rear and side street setbacks measured the same way from each respective property line. Table 8-2-6-1, adopted with the rest of Title 8 by Ordinance 1002 on October 28, 2025, applies those definitions to the Rural Residential (RR) district: the front yard setback is 50 feet where the lot fronts an arterial, collector or section-line street, 30 feet on any other roadway, and 25 feet where the property line does not front a roadway at all.

5-acre Rural Residence option. The interior side setback is 25 feet, but Table 8-2-6-1's note allows a reduced 10-foot side property line setback between two rural residence lots built adjacent to each other. The rear setback is 25 feet under either option. These figures sit alongside Table 8-2-6-1's 10-acre minimum base lot size, 35-foot building height cap and 100-foot minimum street frontage. Where a site's shape, topography or an existing structure makes those setbacks impossible to meet, Section 8-6-31 lets an owner apply to the Board of County Commissioners for a variance under Idaho Code Section 67-6516; the Board must find the relief will not grant a special privilege, will relieve a genuine hardship tied to the site, and will not cause detriment to public health, safety or welfare, and any decision may be appealed under Section 8-6-13.