Benton County, OR Building Setbacks & Zoning: Setback Rules (2026)

405 governs siting for every structure allowed in the Rural Residential (RR) zone, the county's most common unincorporated zoning designation. The setback to a road right-of-way must be at least 25 feet, and at least 40 feet measured from the edge of an existing roadway if that is greater. The side setback is at least 8 feet, but if a structure already exists on the adjoining property, a 30-foot setback must be maintained between the new structure and that existing structure, unless the two dwellings are attached at the property line.

The rear setback is at least 25 feet. Architectural features such as eaves may project no more than 2 feet into any required setback. Structures that are not water-dependent must sit at least 50 feet from the ordinary high water line of a river or major stream, or 25 feet from a creek or minor stream. A dwelling within 200 feet of a forested area needs a spark arrestor on each chimney and a fire-retardant roof, and a 30-foot fire break is required around structures on a parcel bordering the Forest Conservation zone.

Smaller non-residential structures qualify for reduced setbacks under a separate subsection. Every structure must also comply with the general development standards of BCC Chapter 99. These setbacks apply only in unincorporated Benton County; Corvallis, Philomath, Adair Village and Monroe set their own setbacks inside city limits.