Trinity County, CA Building Setbacks & Zoning: Setback Rules (2026)

Because the entire county is unincorporated, Trinity County's zoning ordinance (Title 17) sets building setbacks, and the required yards depend on the parcel's zoning district - there is no single county-wide setback. As a representative example, the R-2 Duplex Residential district requires a minimum front yard of twenty feet (Sec. 17.17.090), interior side yards of six feet and exterior (street-side) side yards of ten feet (Sec. 17.17.100), and a rear yard of twenty feet, with ten feet permitted if at least five hundred square feet of open area per unit is maintained to the side or rear (Sec. 17.17.110). Other districts use different numbers, so owners must look up their own zone. Chapter 17.30's general yard provisions (Sec. 17.30.060) add county-wide rules layered on top: a fifty-foot building setback line is established along all state highways and federal-aid secondary roads measured from the centerline; cornices, eaves, and canopies may project up to thirty inches into a required yard; and on corner lots adjacent to a key lot, the street-side yard within twenty-five feet of the key lot's side line must equal the front yard required on the key lot. Setbacks are measured from official plan lines or established building lines where those exist. Because requirements vary by district and by road frontage, confirm exact setbacks with the Trinity County Planning Division.