How Portland Handles Accessory Structures: A Practical Guide

Portland maintains 203 local ordinances across all categories, and 9 of those deal specifically with accessory structures. Here is a breakdown of what the city actually requires, what is prohibited, and where Portland falls on the strict-to-permissive spectrum compared to other cities.

Tiny Homes

Portland is among the most ADU-friendly cities in the U.S.; tiny homes on foundations qualify as Accessory Dwelling Units under PCC 33.205 and Chapter 33.207, and tiny houses on wheels may park as recreational vehicles subject to time limits.

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Specific penalty amounts for this ordinance are not published in a publicly accessible fine schedule. Contact [Portland code enforcement](https://www.portland.gov/code/33/205) directly for current fines, enforcement procedures, and hearing options.

The rules around tiny homes in Portland lean permissive, but that does not mean anything goes.

Carport Rules

Portland allows open-sided carports as accessory structures in residential zones under PCC 33.110; carports in front yards must meet driveway standards and setbacks.

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Specific penalty amounts for this ordinance are not published in a publicly accessible fine schedule. Contact [Portland code enforcement](https://www.portland.gov/code/33/110) directly for current fines, enforcement procedures, and hearing options.

ADU Impact Fees

Portland's System Development Charge (SDC) waiver for ADUs ended December 31, 2023. As of 2024, ADUs pay SDCs based on size but typically at reduced rates compared to full-size dwellings. Standard SDCs cover transportation, parks, water, sewer, and stormwater. Permit fees through BDS apply separately. Total SDCs for a new ADU range from approximately $11,000 to $19,000.

Key details: Waiver Status: Ended Dec 31, 2023. SDC Range: ~$11,000-$19,000 per ADU. SDC Components: Transportation, Parks, Water, Sewer, Stormwater. Affordable ADU: May qualify for exemption. School CET: ~$1.50/sq ft.

Failure to pay SDCs prevents BDS from issuing a Certificate of Occupancy. Construction without paying assessed SDCs may result in liens on the property. Underreporting ADU size or construction value to reduce SDCs constitutes fraud and can void permits.

Portland is more permissive than most cities when it comes to adu impact fees. That said, there are still limits.

ADU Permits

Portland allows ADUs by-right in all residential zones under Portland City Code Title 33 (Zoning Code) Chapter 33.205. Up to two ADUs are permitted per single-family lot under Oregon HB 2001 and Portland's Residential Infill Project (RIP). Building permits from the Bureau of Development Services (BDS) are required, with streamlined ADU review and pre-approved plans available.

Key details: Code Section: PCC Title 33 Chapter 33.205. ADUs Per Lot: Up to 2. Max Size: 800 sq ft or 75% of main. Max Height: 20 ft detached. Permit Authority: Portland BDS.

Building or occupying an ADU without permits violates Title 33 and the Oregon Structural Specialty Code, triggering BDS stop-work orders, daily fines up to $1,000, and required removal or correction. Unpermitted electrical or plumbing work voids homeowner insurance. Code violations create title issues that affect property sales.

Portland is more permissive than most cities when it comes to adu permits. That said, there are still limits.

ADU Rental Restrictions

Portland ADUs can be rented for long-term residential use without owner-occupancy under Oregon HB 2001. Short-Term Rentals (under 30 days) are regulated by Portland City Code Title 33.207, requiring Accessory Short-Term Rental (ASTR) permits. ASTR permits require host occupancy of the primary dwelling for at least 270 days per year, effectively limiting ADU STR use to owner-occupied properties.

Key details: Long-Term Rules: No owner occupancy required. STR Code: PCC Title 33.207. Owner Stay Requirement: 270 nights/year for STRs. ASTR Fee: $178+ annually. Combined Tax: 13% lodging tax.

Operating an unpermitted ASTR carries fines up to $5,000 per violation under Title 33.207. Booking platforms (Airbnb, VRBO) face penalties for listing unregistered Portland units. Loss of 270-day owner occupancy converts the ASTR to a violation. Tax non-compliance triggers Portland Revenue Division enforcement. Long-term tenant evictions without just cause violate Oregon ORS 90.427.

Shed Rules

Portland exempts one-story accessory structures (sheds) of 200 square feet or less from a building permit under the Oregon Residential Specialty Code, adopted via PCC Title 24. However, even permit-exempt sheds must meet PCC 33.110.250 setback rules (typically 5 ft side/rear) and the accessory-structure standards in PCC 33.110.255 limiting height to 15 feet and footprint to no more than 15% of the lot area in most residential zones.

Key details: Permit-Exempt Size: ≤200 sq ft, one story. Setback (R zones): 5 ft side/rear (PCC 33.110.250). Max Height: 15 ft (PCC 33.110.255). Combined Footprint: ≤15% of lot area. Electrical/Plumbing: Separate permits required.

Building a shed over 200 sq ft without a building permit is a violation under PCC 24.10 with double-fee retroactive permitting and stop-work orders. Setback or height violations are enforced under PCC 33.700 with civil penalties starting at $250/day and required modification or removal. Wiring a shed without an electrical permit is enforced separately by BDS Electrical.

Portland is more permissive than most cities when it comes to shed rules. That said, there are still limits.

ADU Owner Occupancy

Portland removed the owner-occupancy requirement for accessory dwelling units (ADUs) in 2017. Under current PCC 33.205, neither the primary home nor the ADU must be owner-occupied to obtain a permit. This made Portland one of the first U.S. cities to fully decouple ADUs from owner occupancy. Oregon HB 2001 (2019) and HB 2583 (2021) reinforced the policy statewide.

Key details: Rule Status: Removed in 2017. Code Section: PCC 33.205 (Accessory Dwelling Units). State Preemption: Oregon HB 2001 (2019); HB 2583 (2021). STR Exception: PCC 33.207 — 270-day on-site requirement for STRs. SDC Waiver: PCC Title 17.13 (continuing policy).

There is no penalty associated with owner-occupancy since the rule was removed. The only related enforcement is short-term-rental violations under PCC 33.207: operating an ADU as an STR without on-site host presence for 270+ days/year is a violation with fines starting at $1,000 per offense under PCC 33.207.080 and possible permit revocation.

The rules around adu owner occupancy in Portland lean permissive, but that does not mean anything goes.

ADU Rules

Portland allows accessory dwelling units (ADUs) on every single-dwelling residential lot under PCC 33.205. ADUs can be attached, internal (basement/attic conversion), or detached and may be up to 75% of the primary dwelling's living area or 800 sq ft, whichever is greater. No additional parking is required, no owner-occupancy is required, and System Development Charges are waived under PCC Title 17.13.

Key details: Code: PCC 33.205 (Accessory Dwelling Units). Size Limit: Greater of 800 sq ft or 75% of main dwelling. Detached Height: 20 ft (more under RIP standards). Parking Required: None. Owner Occupancy: Not required (removed 2017).

Building an ADU without a permit is enforced by BDS as a building/zoning violation under PCC 24.10 and 33.700, with stop-work orders and double-fee retroactive permits, plus civil fines starting at $250/day. ADUs exceeding size or height limits must be modified or removed. Short-term rental of an ADU without an STR permit is a separate violation under PCC 33.207.080.

If you are coming from a city with tighter rules, you will find Portland gives residents more flexibility on adu rules.

Garage Conversions

Converting a garage to living space in Portland requires a building permit and typically trade permits. If the conversion creates an independent unit with kitchen and bathroom, it qualifies as an ADU under Chapter 33.205. Off-street parking considerations apply.

Key details: Building Permit: Required for conversion to habitable space. ADU Trigger: Independent unit with kitchen + bathroom = ADU (PCC 33.205). Trade Permits: Electrical, plumbing, mechanical permits required. Parking Impact: Required primary home parking must be maintained or relocated. SDC Waiver: Available with 10-year rental commitment, no STR use.

Unpermitted conversion: building code enforcement. Must bring to code or restore. Safety violations: immediate correction.

The Bottom Line

Compared to many U.S. cities, Portland gives residents more room on accessory structures. 6 of the 9 rules here are rated permissive. But permissive does not mean unregulated. There are still requirements, and the city does enforce them when violations are reported.

All of the above reflects Portland's municipal code as of our last review. If you need specifics on fines, exemptions, or filing requirements, the detailed ordinance pages linked above have the full breakdown.