Washington County, OR Building Setbacks & Zoning: Structure Height Limits (2026)

Structure heights in unincorporated Washington County are set by CDC Chapter III zone tables, measured from average finished grade to the highest point of the roof (not including chimneys, antennas, and approved mechanical). R-5, R-6, R-9 residential zones: 35 ft maximum. R-15, R-24, R-25+: 45 ft. Commercial and industrial zones along Tualatin Valley Highway, Cornell Rd, and Tanasbourne: up to 60-75 ft depending on sub-district. Transit Oriented (TO) zones near MAX Blue Line stations at Orenco, Hawthorn Farm, Quatama, Willow Creek, and Sunset allow taller buildings. Intel's Ronler Acres and Aloha campuses have industrial height envelopes exceeding 100 ft for specific fab buildings approved under Master Plans. Hillsboro Airport (HIO) Part 77 imaginary surfaces restrict heights on final approach corridors across Hillsboro, Orenco, and Tanasbourne — any structure penetrating these surfaces requires FAA Form 7460-1 notice. Cities within the county: Beaverton BDC 60 caps residential at 35 ft similarly; Hillsboro Station Community Plan allows higher in transit core; Tigard's downtown Urban Renewal District allows up to 80 ft. Wireless tower heights regulated separately under CDC §430-123.