Portland, OR · Updated 2026
Portland ADU Permits: Fees, Timeline & Process
Oregon's ADU capital — SDC waivers, pre-approved plans, and no parking requirements.
Quick Answer
Portland ADUs: $150K–$400K
Permits: $18K–$42K · Updated April 2026
Portland ADU Permitting: Overview
Portland is one of the most ADU-friendly cities in the country. Oregon law requires all cities to allow ADUs on any residential lot, and Portland has gone further with pre-approved plans, SDC waiver programs, and streamlined permitting. The city processes ADU permits through Portland Permitting & Development (PP&D), with most reviews completed in 6–12 weeks.
Portland's SDC waiver program is a major cost saver — if you agree not to use the ADU as a short-term rental for 10 years, the city waives System Development Charges that can total $15,000–$37,000. Pre-approved plans from the City of Eugene (adapted for Portland) are available free of charge and can significantly speed up the review process.
Permit Fees Breakdown
Total permitting costs in Portland typically range from $18,000–$42,000 depending on ADU type, size, and site conditions.
| Fee Type | Amount | Notes |
|---|---|---|
| Building Permit | $900–$2,000 | Based on project valuation |
| Plan Review | $570–$1,300 | Building + residential site plan review |
| Land Use Review | $250–$580 | Zoning compliance verification |
| Sanitary SDC (BES) | $6,640 | Waivable with 10-year covenant |
| Parks SDC | $7,100 | Waivable with 10-year covenant |
| Transportation SDC (PBOT) | $2,940 | Waivable with 10-year covenant |
| Water SDC | $2,280 | Plus $8,070 domestic service connection |
| School Excise Tax | $750–$1,000 | Based on square footage |
| State Surcharges | $320–$500 | Building, mechanical, plumbing, electrical |
Fees are estimates based on typical ADU projects. Contact Portland permitting for exact quotes. See our full permit fees guide for comparison across cities.
Zoning & Requirements
- ADUs allowed on any residential lot in Portland — no minimum lot size
- One ADU per lot (detached or attached); two ADUs may be allowed on some lots
- Maximum size: 75% of primary dwelling or 800 sq ft, whichever is less
- Height limit: 20 feet for detached ADUs
- Setbacks: 5 feet side/rear for detached; reduced to 0 for conversions
- No parking required for ADUs
- No owner-occupancy requirement
Step-by-Step Permit Process
Check zoning & eligibility
Use Portland Maps to verify your lot qualifies. Most single-family residential lots are eligible.
Select or create plans
Choose from free pre-approved plans or hire an architect for custom designs. Pre-approved plans skip much of the review process.
Submit permit application
Apply online through the PP&D Development Hub. Include site plan, floor plans, elevations, structural calculations, and energy compliance docs.
Pay plan review fees
Building, land use, and site plan review fees are due at submission.
Plan review (6–12 weeks)
Zoning, building, fire, and public works departments review plans. Respond to any correction notices within 2 weeks.
Pay SDCs and permit fees
Pay remaining fees including SDCs (or apply for the SDC waiver). Permit is issued once all fees are paid.
Construction & inspections
Schedule inspections at each phase: foundation, framing, rough mechanical, insulation, and final.
Certificate of Occupancy
Pass final inspection to receive your CO. The ADU is now legal for occupancy.
Key Regulations & Laws
Oregon HB 2001 (2019)
Requires all Oregon cities to allow ADUs on any residential lot. Portland complied and expanded beyond minimum requirements.
SDC Waiver Program
Homeowners who covenant not to use the ADU as a short-term rental for 10 years can have SDCs waived — saving $15,000–$37,000.
No Parking Mandate
Portland does not require additional parking for ADUs, freeing up yard space and reducing project costs.
Pre-Approved Plans
Free pre-approved plans available through the city, originally developed by the City of Eugene. These meet building code and speed up review.
Frequently Asked Questions
How much does an ADU permit cost in Portland?
Building permit and plan review fees run $3,000–$5,000. System Development Charges add $15,000–$37,000, but these can be waived through Portland's SDC waiver program if you agree not to short-term rent the ADU for 10 years. Total fees range from $3,000 (with waiver) to $42,000 (without).
How long does ADU permitting take in Portland?
Most permit reviews take 6–12 weeks after a complete application is submitted. Pre-approved plans can reduce this timeline. The full project from design to move-in typically takes 10–16 months.
Do I need to live on the property to build an ADU in Portland?
No. Portland has no owner-occupancy requirement for ADUs. You can build an ADU and rent both the main house and the ADU.
Can I use my ADU as an Airbnb in Portland?
Yes, but if you received an SDC waiver, you cannot use the ADU as a short-term rental for 10 years. Without the waiver, short-term rentals are allowed subject to Portland's short-term rental regulations.
Your Next Steps
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