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

The Community Development Code's R-5 District, Washington County's standard residential zone allowing four to five dwelling units per acre, sets the baseline height standard applied across most unincorporated single-family neighborhoods. C caps the maximum height for structures at 35 feet, covers detached houses and manufactured dwellings, and separately limits accessory structures such as garages, workshops and sheds to 15 feet. The code carves out one exception: rooftop appurtenances, including spires, belfries, cupolas, chimneys, ventilators and elevator housings, may extend above the 35-foot line up to a hard ceiling of 60 feet.

Detached dwellings and manufactured homes must also satisfy the separate Solar Balance Point Standard of Section 427-4, which can further limit height depending on the shadow a new structure would cast on a neighboring lot to the north. 1, duplexes, triplexes, quadplexes and townhouses, follow a different table: 35 feet for the dwellings themselves and only 25 feet for cottage cluster units and their shared community buildings, with the same 60-foot cap on qualifying rooftop projections. 1 from the average finished ground level at the center of a building's walls to the highest point of a flat roof, the deck line of a mansard roof, or the mean point between eaves and ridge on a gable, hip or gambrel roof.

F allows the Review Authority to approve up to 45 feet in R-5 and R-6 districts and up to 100 feet in other districts permitting Planned Developments, but never higher than 100 feet. These standards apply only outside Hillsboro, Beaverton, Tigard, Tualatin, Sherwood, Forest Grove, Cornelius, King City, North Plains, Banks, Gaston and the slice of Portland inside the county; each city enforces its own height limits within its boundaries.