ADU rules in Washington County, OR — also called accessory dwelling unit regulations or granny flat ordinances — cover setbacks, owner-occupancy, parking, and permit requirements.
ADUs are allowed in unincorporated Washington County per Oregon state law (ORS 197.312(5)). Cities must allow ADUs on single-family lots. Oregon HB 2001 (2019) requires larger cities to allow middle housing. Parking minimums for ADUs are eliminated near transit under state law.
Oregon state law requires all cities and counties to allow ADUs on lots zoned for single-family dwellings. No owner-occupancy requirement per state law. The Community Development Code establishes specific development standards for ADUs in unincorporated areas including setbacks (CDC 418) and lot coverage limits. Building permits are required.
Unpermitted ADU: standard building code enforcement. May require legalization or demolition. Occupying unpermitted unit: code violation.
Washington County, OR
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Washington County, OR
Washington County requires electrical permits for Level 2 EV chargers under OAR 918-311-0065. HOAs cannot prohibit EV charger installation on owner property ...
Washington County, OR
Washington County Sheriff enforces parking regulations in unincorporated areas. Parking against traffic, storing vehicles on streets, parking over 18 inches ...
Washington County, OR
Washington County Sheriff's Office tags and tows abandoned vehicles on public rights-of-way under ORS 819.110 and county Chapter 8.16. A vehicle on public st...
Washington County, OR
Washington County requires a building permit for retaining walls over 4 feet tall measured from the bottom of foundation to top of wall (CDC 419-4). Walls su...
Washington County, OR
Washington County Community Development Code §411 permits standard residential fencing materials — cedar, vinyl, composite, wrought iron — and prohibits barb...
See how Washington County's adu rules rules stack up against other locations.
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