ADU Construction permits in Oregon
What Oregon building departments require for adu construction, what it adds to a $168,000 – $336,000 project, and how the rules differ across 10 cities we track in the state.
The Oregon permit process, step by step
Confirm whether your scope is permitted work
In Oregon, structural, electrical, plumbing, mechanical and most exterior envelope work on adu construction projects triggers a permit. Cosmetic, like-for-like repairs often do not.
Let the licensed contractor pull it
A contractor who asks you to pull an owner-builder permit is shifting liability to you. Whoever pulls the permit is responsible for code compliance.
Budget for fees and plan review
Permit fees are usually a percentage of job valuation plus a flat plan-review fee. On a typical Oregon adu construction project of $168,000 – $336,000, expect permitting to be a low single-digit percentage of the total.
Schedule inspections before you close things up
Rough-in inspections have to happen before drywall, backfill or roofing covers the work. A missed inspection can mean tearing finished work back out.
Keep the final sign-off
The closed permit and certificate of completion belong in your home file — buyers, appraisers and insurers all ask for them on permitted work.
City-by-city permit notes
| City | Local permit note | Typical project |
|---|---|---|
| Portland | City permits and design review can add weeks to exterior projects. | $177,000 – $354,000 |
| Salem | City permits for structural, mechanical and exterior work. | $159,000 – $318,000 |
| Eugene | City permits with energy-code compliance. | $157,500 – $315,000 |
| Gresham | City permits required for roofing and structural work. | $165,000 – $330,000 |
| Hillsboro | City permits apply to most remodel and exterior projects. | $171,000 – $342,000 |
| Bend | City permits with wildfire-hardening requirements in some zones. | $174,000 – $348,000 |
| Beaverton | City permits required for structural and exterior work. | $172,500 – $345,000 |
| Medford | Most Medford, OR projects that change structure, electrical, plumbing or mechanical systems need a permit from the local building department; cosmetic work usually does not. | $165,000 – $330,000 |
| Springfield | Most Springfield, OR projects that change structure, electrical, plumbing or mechanical systems need a permit from the local building department; cosmetic work usually does not. | $163,500 – $327,000 |
| Corvallis | Most Corvallis, OR projects that change structure, electrical, plumbing or mechanical systems need a permit from the local building department; cosmetic work usually does not. | $168,000 – $336,000 |
ADU Construction permit FAQs for Oregon
Permit requirements are set locally and change. Confirm details with your city or county building department before starting work. Typical statewide project value used here: $252,000.