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

Twin Falls County Code § 8-6A-5(D) sets the yard, or setback, requirements for the Agricultural Range Preservation (ARP) zone, the county's largest unincorporated zoning district covering the nonirrigated high desert range outside the cities' areas of impact. Every building needs a minimum 30-foot front yard depth, unless the building exceeds 35 feet in height, in which case the front yard grows by one additional foot for every five feet of height over 35 feet. The minimum side yard on an interior lot is 7 feet on each side of the main building, subject to the same one-foot-per-five-feet height step-up past 35 feet; a corner lot's side street yard cannot be less than 25 feet.

The rear yard follows the front yard's rule: a 30-foot minimum, growing a foot for every five feet of height above 35 feet. These setbacks sit inside a zone with a base density of one dwelling per 160 contiguous acres under § 8-6A-1, and lot frontage rules in § 8-6A-5(B) require at least 80 feet of average lot width and 60 feet of street frontage, or 30 feet on a cul-de-sac. Because § 8-5-5 makes the district's setback minimums a floor that can never be reduced once built, any deviation from these numbers requires review by the Planning and Zoning Commission rather than an administrative sign-off. The Zoning Administrator's office in the Planning Department checks yard dimensions at the building permit stage before construction begins.