ADU Regulations in Oregon (OR)
Oregon is rated Easy for ADU construction with an ADU-friendliness score of 93/100 (Very ADU-Friendly). Oregon has a statewide ADU law that sets baseline rules across all municipalities. No owner-occupancy requirement. No additional parking required for ADUs. Oregon has been an ADU pioneer. HB 2001 (2019) requires cities over 2,500 population to allow at least 2 ADUs per single-family lot. HB 3395 (2023) further streamlined ADU permitting and eliminated owner-occupancy requirements. Portland leads the nation in per-capita ADU construction. Impact fees are limited for smaller ADUs.
Full ADU Regulations Summary for Oregon
| ADUs Allowed | Yes |
| Statewide ADU Law | Yes |
| Maximum ADU Size | 900 sq ft |
| Owner Occupancy Required | No |
| Parking Required | No |
| Minimum Setback | 5 ft |
| Permitting Timeline | 60 days max |
| Impact Fees | Exempt for ADUs under 750 sq ft |
| Long-Term Rental Allowed | Yes |
| Short-Term Rental (Airbnb) Allowed | Yes |
| Ease of Building | Easy |
ADU Regulations by City in Oregon
ADU rules can vary by city even within the same state. While Oregon's statewide law sets minimum standards, some cities have additional local provisions. Below are ADU details for 4 cities in Oregon.
Portland
Portland is a national leader in ADU construction. ADUs allowed by right. Up to 2 ADUs per lot. No owner occupancy, no parking. Pre-approved ADU plans available. SDC (impact fee) waivers available.
Eugene
ADUs allowed on all single-family lots. Eugene permits both attached and detached ADUs. No additional parking required.
Bend
ADUs permitted by right. Bend has high ADU demand due to housing costs. No owner-occupancy requirement.
Salem
ADUs allowed per state law. Salem updated zoning for ADU compliance. Growing ADU construction.
How Oregon Compares to Other States
Below is a comparison of Oregon with five states that have similar ADU-friendliness scores. This comparison helps illustrate where Oregon stands nationally.
| State | Score | Statewide Law | Parking Req? | Owner Occ? | Ease |
|---|---|---|---|---|---|
| Oregon (OR) | 93 | Yes | No | No | Easy |
| Arizona (AZ) | 93 | Yes | No | No | Easy |
| California (CA) | 93 | Yes | No | No | Easy |
| Colorado (CO) | 91 | Yes | No | No | Easy |
| Vermont (VT) | 95 | Yes | No | No | Easy |
| Washington (WA) | 96 | Yes | No | No | Easy |
Frequently Asked Questions About ADUs in Oregon
Can I build an ADU in Oregon?
Yes, ADUs are allowed in Oregon. Oregon has a statewide ADU law that requires local jurisdictions to permit ADUs on residential lots. This means your city cannot outright ban ADUs. The ease of building is rated "Easy" with a friendliness score of 93/100.
Do I need to live on the property to have an ADU in Oregon?
No, Oregon does not require owner occupancy for ADUs. You can rent out both the main house and the ADU, which maximizes rental income potential.
How big can an ADU be in Oregon?
The state maximum ADU size in Oregon is 900 square feet. Local jurisdictions may set lower limits. Some cities also limit ADU size to a percentage of the primary dwelling (e.g., 50%).
Do I need extra parking for an ADU in Oregon?
No, Oregon does not require additional parking for ADUs. This is a significant advantage, as parking requirements are often the biggest barrier to ADU construction on smaller lots.
Can I rent out my ADU in Oregon?
Yes, long-term rentals of ADUs are allowed in Oregon. Short-term rentals (like Airbnb) are also generally permitted, though your city may have separate short-term rental regulations.
How long does it take to get an ADU permit in Oregon?
The permitting timeline in Oregon is: 60 days max. The statewide law sets maximum review periods that cities must comply with. Actual timelines can be affected by plan review backlogs, inspection scheduling, and the complexity of your project. Pre-approved ADU plans, where available, can significantly speed up the process.
Check ADU Rules for Your City
Use our ADU regulations lookup tool to find the specific rules for your city in Oregon, or browse all 50 states to compare ADU regulations across the country. Remember that local rules may be more specific than state-level regulations.