Oregon Statewide Accessory Dwelling Unit Mandate

Oregon Senate Bill 1051 (2017), now codified at ORS 197A.425 after the 2023 land-use recodification, requires local governments to permit accessory dwelling units on single-family residential lots within urban growth boundaries. Cities cannot ban ADUs outright, require owner occupancy, or mandate off-street parking, and may impose only reasonable building, dimensional, and design standards. House Bill 2001 (2019) separately expanded duplex and middle-housing requirements in larger cities. Local jurisdictions retain authority over specific height, setback, and design standards within these state-imposed limits.

Local ordinances that ban ADUs or impose unreasonable restrictions are unenforceable. Owners may challenge them at the Land Use Board of Appeals under ORS 197.825.