Oregon Statewide Rule
Oregon Allows One Accessory Dwelling Per House (ORS 197A.425)
Key Facts
- Governing statute
- ORS 197A.425
- Applies to
- Cities >2,500, counties >15,000
- ADUs required
- One per detached house
- Owner-occupancy
- Cannot be required
- Extra parking
- Cannot be required
Summary
Oregon requires every city over 2,500 people and every county over 15,000 to allow at least one accessory dwelling unit for each detached single-family house inside the urban growth boundary. Cities cannot demand owner-occupancy or extra off-street parking, so a tiny house on a foundation qualifies.
A city with a population greater than 2,500 or a county with a population greater than 15,000 shall allow in areas within the urban growth boundary that are zoned for detached single-unit dwellings the development of at least one accessory dwelling unit for each detached single-unit dwelling, subject to reasonable local regulations relating to siting and design. ... “Reasonable local regulations relating to siting and design” does not include owner-occupancy requirements of either the primary or accessory structure or requirements to construct additional off-street parking.
Full Breakdown
The mandate is ORS 197A.425, from 2017's Senate Bill 1051. It defines an accessory dwelling unit as an interior, attached, or detached residential structure accessory to a single-unit dwelling, so a tiny house on a foundation fits. A city over 2,500 or a county over 15,000 must allow one such unit per detached single-unit dwelling in areas within the urban growth boundary zoned for those dwellings, subject only to reasonable local siting and design rules. Owner-occupancy conditions and mandatory added off-street parking are expressly barred. The Department of Land Conservation and Development administers Chapter 197A, and the Housing Accountability and Production Office can act against noncompliant jurisdictions.
Violations & Penalties
A local ban, owner-occupancy condition, or extra-parking requirement that conflicts with ORS 197A.425 is unenforceable. Applicants can appeal a wrongful denial to the Land Use Board of Appeals, and the state Housing Accountability and Production Office can compel a city to comply.
Frequently Asked Questions
Can a tiny house be an ADU in Oregon?
Can my city require me to live on-site to have an ADU?
Does this rule apply everywhere in Oregon?
Sources
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