ADU Pass
Portland
Multnomah County portion
Also in: Clackamas County · No County · Washington County
ADU Pass helps homeowners in Portland, Multnomah County, Oregon navigate the permit paperwork for building an accessory dwelling unit. This area covers 28 ZIP codes.
Map
ADU details
ADU legality: allowed
Portland's flagship policy lever is the SDC Waiver Program (since 2010, extended 2018, made permanent thereafter): 100% waiver of system development charges in exchange for a 10-year covenant against short-term rental use. The waiver routinely saves property owners $15,000-$25,000.
Cost scenarios
| Scenario | Sq ft | Permit | Build | Total |
|---|---|---|---|---|
| minimum | 400 | $4,800 | $156,000 | $160,800 |
| 600 | 600 | $7,200 | $282,000 | $289,200 |
| midpoint | 700 | $8,500 | $336,000 | $344,500 |
| 800 | 800 | $10,200 | $400,000 | $410,200 |
Fee breakdown (as of 2026-04)
Permitting process
- Pre-application research (~7d)
Pull PortlandMaps parcel report; confirm zone (R5/R2.5/RM), historic overlay (h-zone), Willamette River SFHA, slope (Hillside Constraint), neighborhood plan area; choose pre-approved plan vs custom; decide whether to file SDC waiver covenant. - Submit via Development Hub PDX (~1d)
Submit through Development Hub PDX (devhub.portlandoregon.gov): building permit application, site plan, architectural plans (or pre-approved set), structural plans, ORSC energy worksheet. SDC waiver covenant submitted via dedicated digital form. - Concurrent multi-bureau plan review (~56d)
Permitting & Development (PPD), Bureau of Environmental Services (BES) sewer, Portland Water Bureau (PWB), Portland Bureau of Transportation (PBOT) ROW, Bureau of Development Services historic if applicable. - Corrections cycle (typically 2-3 rounds) (~28d)
Resubmit corrections via Development Hub. Portland's multi-bureau review structure produces more checksheets than smaller cities. - SDC waiver approval & permit issuance (~7d)
Covenant recorded against the property; SDC waiver applied; remaining permit/connection fees paid; permit issued within ~7 business days after payment. - Construction & inspections
Foundation, framing, MEP rough, insulation, drywall, final. Inspections via PPDinspections@portlandoregon.gov or 503-823-7388. - Certificate of occupancy (~5d)
Final inspection sign-off; ADU eligible for occupancy and long-term rental (STR prohibited under SDC-waiver covenant for 10 years).
Viability (permitted uses)
- Long-term rental: yes (PCC 33.205; ORS 90 (Oregon Residential Landlord & Tenant Act); Portland Renter Protections (PCC 30.01)) 30+day rental allowed. Portland's tenant protections (relocation assistance for no-cause terminations or rent increases >10%) apply to ADU tenancies.
- Short-term rental: with-restrictions (PCC 33.207 - Accessory Short-Term Rentals (ASTR); SDC Waiver Covenant prohibits ADU as STR for 10 years) Critical fork: SDC-waiver participants cannot STR. Non-waiver ADUs may STR with ASTR permit. Most Portland ADUs take the waiver, so STR is effectively foreclosed for the majority.
- Properties that took the SDC waiver are barred from ASTR for 10 years
- ASTR Type A permit required for any STR up to 2 bedrooms
- Owner must reside on site 270+ nights/year for ASTR Type A
- Transient lodging tax registration required
- Office rental: no PCC 33.205 limits ADU to dwelling-unit use.
- Home office: yes Home occupation under PCC 33.203 permitted; foot-traffic and signage limits apply.
- Studio / workshop: yes Personal artist/maker studio is an allowed accessory residential use.
- Agriculture: with-restrictions (PCC Title 33 - urban agriculture, Title 13 hen-keeping) Backyard agriculture and limited livestock allowed; ADU itself remains residential dwelling.
- Relative support: yes Family-occupancy explicit; Portland was an early national pioneer of ADU-as-multigenerational-housing.
Incentives
- Portland ADU SDC Waiver Program (since 2010) — 100% waiver of city System Development Charges (~$18,000-$25,000) in exchange for a 10-year covenant against short-term-rental use of either the ADU or the primary dwelling. Penalty for breach: 150% of current SDC rates. The longest-running and most generous ADU SDC waiver in Oregon.
- Portland Pre-Approved ADU Plans (4 designs) — City offers 4 pre-approved detached ADU designs (gable/shed roof variants, slab/crawl space). PDFs free to download.
Pre-approved plans Portland Pre-Approved ADU Plans · 4 free designs · 30% plan-review fee waiver · saves ~6 weeks
Contacts
Staff: Residential Inspections (Building Inspections), Development Services Center (Counter intake (Tues/Thurs 8am-4pm)), Bureau of Environmental Services (Sewer & stormwater review), Portland Water Bureau (Water service review)
Utilities
- Water: Portland Water Bureau (PWB) · 30d connect · $2,900
- Sewer: Portland Bureau of Environmental Services (BES) - combined sewer in central neighborhoods · 25d connect · $1,300
Combined-sewer service area requires stormwater management plan when adding impervious area; outer SE/NE neighborhoods have separated stormwater. - Electric: Portland General Electric (PGE) - east of Willamette; Pacific Power - small NW Portland slice · 35d connect · $1,850
- Gas: NW Natural · 30d connect · $1,450
Property values & taxes
Market rent by ADU size
| Sq ft | Rent |
|---|---|
| 400 | $1,450/mo |
| 600 | $1,850/mo |
| 800 | $2,275/mo |
Construction timeline
Realistic total: best 9mo · typical 14mo · worst 22mo
PNW wet season + multi-bureau plan-review backlog drive long worst-case. Portland's mature ADU specialist contractor pool (50+ firms) is the deepest in Oregon but lead times are correspondingly long.
Modular pathway Oregon BCD Manufactured Structures Program · inspectors are frequent with modular · 38 modular permits (last 24mo)
Multiple bridge clearances over Willamette and Columbia; West Hills steep narrow roads restrict module width; central east-side narrow lots common.
Financing
State ADU loans:
- Oregon ADU Loan (when funded by NOFA) (Oregon HCSD) up to $50,000
Insurance impact
Portland tenant protections increase landlord exposure (relocation assistance, no-cause termination penalties). West Hills wildfire and Willamette/Columbia flood zones add carrier scrutiny.
HOA prevalence & preemption
Portland HOA prevalence concentrated in master-planned developments and condo-conversions. State law voids ADU bans in covenants.
Regulatory overlays (5)
- historic-district — h-zone overlays in Alphabet, Yamhill, East Portland Grand Ave, Skidmore-Old Town, Ladd's Addition, Irvington, Mock's Crest, etc. · +35d · +10% cost
BDS Historic Resource Review for new construction in h-zone or modifications to contributing structures; routine 35-day extension to plan check. (map) - wui-fire-zone — West Hills (Forest Park edge), Mt. Tabor, Powell Butte slopes · +14d · +7% cost
Defensible space and ignition-resistant assemblies on wildland-urban interface parcels in West Hills and east Portland buttes. (map) - flood-zone — FEMA SFHA Zone AE along Willamette River and Columbia River; Columbia Slough corridor; Johnson Creek (SE Portland) · +14d · +7% cost
Finished-floor elevation 1 ft above BFE. Columbia River parcels and Johnson Creek corridor most affected; West Hills generally above SFHA. (map) - seismic-retrofit-zone — Cascadia Subduction Zone + Portland Hills Fault + East Bank Fault · +7d · +4% cost
Seismic Design Category D1; ORSC 2023 hold-down standards. Liquefaction zones in central east-side and waterfront. (map) - other — Hillside Constraint (slopes 25%+) and Environmental Conservation/Protection (e overlay) · +21d · +12% cost
Hillside parcels (West Hills, Mt. Tabor, Mt. Scott) require geotech and may need supplemental land-use review. Environmental overlay (Forest Park edge, river bluffs) constrains tree removal and impervious area. (map)
Technical envelope (climate & building code)
Climate & energy code
Building code
Amendments:
- Portland Local Building Amendments — Local amendments addressing seismic anchoring, hillside grading on West Hills slopes, BES stormwater management, EV-ready requirements.
Contractor market (aggregate)
Legal history (timeline)
Current ordinance: Portland City Code (PCC) Title 33 Chapter 33.205 - Accessory Dwelling Units, adopted 1998-01-01, last amended 2025-01-01
- 2010-04-01 — Portland ADU SDC Waiver Program Inaugural (city-ordinance)
Portland City Council originally adopted a temporary System Development Charges waiver for ADUs to spur housing creation post-recession.
Effect: Triggered a documented surge in Portland ADU permitting from ~50/year to several hundred/year. Other Oregon cities subsequently studied Portland's program. - 2018-06-27 — ADU SDC Waiver Extension with Conditions (Ord 188975) (city-ordinance)
Council extended the SDC waiver indefinitely but added a 10-year short-term-rental restriction covenant. Owner-occupancy was eliminated as a permit condition.
Effect: Locked in fee waiver permanently while requiring participants to commit the ADU and primary dwelling to long-term housing for a decade. Penalty for breach: 150% of current SDC rates. - 2019-08-08 — Oregon HB 2001 effective date (state-law)
Statewide middle-housing law preempting local ADU restrictions in cities >2,500.
Effect: Codified statewide what Portland had already done locally; reinforced no-owner-occupancy / no-parking framework. - 2021-08-01 — Residential Infill Project (RIP) - Phase 2 Effective (city-ordinance)
Phase 2 of Portland's Residential Infill Project added expanded middle-housing types and refined ADU treatment for split-zoned and corner lots.
Effect: Allowed ADU + duplex/triplex combos on a single lot; clarified ADU treatment in R5 / R2.5 / RM zones. - 2024-09-01 — ADU SDC Waiver Online Form Launch (city-ordinance)
City debuted a dedicated digital intake for the SDC waiver covenant, replacing paper-and-counter process.
Effect: Cut covenant-execution time from several weeks to days; moved tracking into Development Hub PDX. - 2025-01-01 — PCC 33.205 Code Refresh (city-ordinance)
Conforming amendments updating ADU development standards for height calculation, basement ADU treatment, and accessory-structure stacking.
Effect: Clarified ADU height measurement and added explicit allowance for stacked ADUs over garages.
Known issues (2)
- process-backlog (since 2024-01) — Plan check averages 8-10 weeks; corrections cycles add 4-6 weeks. Pre-approved plans cut total time by ~6 weeks but BES sewer review often remains the long pole. (source)
- policy-tradeoff (since 2018-06) — 10-year STR prohibition tied to SDC waiver narrows Portland investor pool to LTR-focused operators. Breach penalty (150% of current SDC rates) is meaningful. (source)
Multnomah County — county ADU rules and overlays
County ADU ordinance
Multnomah County, OR (815,000 residents including Portland) administers a county zoning code only for unincorporated territory; the great majority of the county is inside Portland, Gresham, Troutdale, Fairview, Wood Village, or Maywood Park. Oregon's SB 1051 (2017) and HB 2001 (2019) require cities of 25,000+ population to allow at least one ADU on lots zoned for single-family detached, with limited regulatory power over ADU design. Portland's ADU rules are among the most permissive in the United States.
State-floor overlay: Oregon HB 2001 / SB 1051 preemption applies.
County regulatory overlays
Multnomah County administers flood-hazard, and (where mapped) coastal, wildland-fire, historic, and airport overlays that shape ADU project feasibility. The most consistent overlay across the county is FEMA NFIP floodplain regulation; other overlays apply to specific geographies inside the county.
- FEMA NFIP Special Flood Hazard Areas in Multnomah County — A new ADU in a mapped SFHA must be elevated to or above the Base Flood Elevation; cost impact on the project is often material.
- Coastal / hurricane wind exposure — Confirm design wind speed and exposure category at the building department.
- Wildland-Urban Interface (WUI) hazard areas
- Historic districts and individually-listed historic resources
County permitting (unincorporated parcels)
Multnomah County issues building permits for parcels in unincorporated territory through its development services / planning department, with separate review tracks for zoning conformance, building-code compliance, on-site sewage where applicable, floodplain compliance, and addressing. Inside incorporated municipalities, city departments handle their own permits; the county's authority is geographically limited to unincorporated territory. An ADU permit application is typically processed as a residential building permit with a zoning verification step against the county's ordinance for the parcel's zoning district.
Oregon state — ADU law and programs
State ADU law
Oregon has the most comprehensive statewide ADU preemption framework in the country after California. House Bill 2001 (2019), codified principally at ORS 197.312(5), requires every Oregon city of more than 2,500 residents inside an urban growth boundary, and every Oregon county with population over 15,000, to allow at least one accessory dwelling unit (interior, attached, or detached) by right for each existing or newly-constructed single-family detached dwelling on residentially-zoned lots. Local jurisdictions may impose 'reasonable regulations' on siting and design but may NOT require owner-occupancy of either the primary or accessory unit and may NOT require additional off-street parking. Senate Bill 458 (2021), codified at ORS 92.031, authorizes 'middle housing land divisions' that allow each unit of a duplex / triplex / quadplex / townhouse / cottage cluster to be partitioned onto its own lot for fee-simple sale via an expedited land-division process; SB 458 does not directly add an ADU mandate but interacts with HB 2001 because an existing ADU can be split off onto its own lot under SB 458's expedited process (although a new ADU cannot be created after a SB 458 division). HB 2001 also separately preempts single-family-only zoning in cities over 25,000 by mandating duplexes statewide (and triplexes, quadplexes, townhouses, and cottage clusters in larger cities), which is the 'middle housing' provision discussed alongside ADUs in DLCD guidance.
- ORS 197.312(5) — Limitation on city and county prohibitions on accessory dwelling units — The codified ADU preemption provision originating in HB 2001 (2019). Requires cities >2,500 within an urban growth boundary and counties >15,000 to allow at least one ADU by right per single-family detached dwelling on residentially-zoned lots. Bars owner-occupancy mandates and additional off-street parking requirements; allows reasonable siting and design regulations.
- ORS 197.758 — Middle housing in lower density residential zones (HB 2001 'middle housing' codification) — Companion to the ADU provision. Mandates that cities >25,000 allow duplexes, triplexes, quadplexes, townhouses, and cottage clusters in residential zones; cities 10,000-25,000 must allow duplexes. Operative January 1, 2020 with municipal compliance deadline July 1, 2021 (cities <25k) or July 1, 2022 (cities >25k).
- ORS 92.031 — Middle housing land divisions (SB 458 (2021)) — Authorizes expedited land divisions that put each middle housing unit on its own lot for fee-simple sale. Applies to middle housing land divisions submitted on or after June 30, 2022. Existing ADUs may be split off via SB 458; new ADUs may not be created after a SB 458 division.
- House Bill 2001 (2019) Enrolled — 80th Oregon Legislative Assembly — Session law text amending ORS 197.312 and creating the middle housing mandate. Effective August 8, 2019; ADU and middle housing provisions operative January 1, 2020 with municipal compliance windows running through 2022.
- Senate Bill 458 (2021) A-Engrossed — 81st Oregon Legislative Assembly — Session law text adding the middle housing land division to ORS Chapter 92. Effective June 23, 2021; operative for applications on or after June 30, 2022.
State housing programs
Oregon's state-level ADU policy infrastructure is concentrated in the Department of Land Conservation and Development (DLCD), which publishes guidance documents for cities and counties implementing ORS 197.312(5) and ORS 197.758, runs the Housing Choice and Middle Housing technical-assistance programs, and audits municipal compliance with HB 2001. Oregon does not currently maintain a statewide pre-approved ADU plan catalog (those exist at the city level, e.g. Portland's pre-approved ADU plans), and there is no statewide impact-fee waiver, no statewide streamlined-review timeline floor beyond the reasonable-regulation requirement of ORS 197.312(5), and no state ADU rebate program.
- DLCD ADU implementation guidance — Statewide guidance to local governments on what 'reasonable regulations' on ADU siting and design under ORS 197.312(5) means in practice. Updated September 2019 to coincide with HB 2001 enactment.
- DLCD Housing Choice / Middle Housing technical assistance — Ongoing TA program that supports cities and counties in updating development regulations to comply with HB 2001 (ADUs and middle housing) and SB 458 (middle housing land divisions).
Federal (United States) — ADU-relevant rules and programs
Federal ADU law
The United States has no federal statute that directly regulates accessory dwelling unit entitlement or design. Land-use authority over ADUs resides with states and local governments under the traditional police power. Federal engagement is limited to financing (Fannie/Freddie/FHA/VA/USDA), flood insurance (FEMA/NFIP), and discretionary housing programs (HUD), which are recorded in sibling sections of this file.
Federal financing programs
Federal housing-finance agencies and GSEs set nationwide underwriting rules that govern whether an ADU can be financed, appraised, and counted toward mortgage qualifying income. The relevant actors are Fannie Mae, Freddie Mac, FHA (HUD), VA, and USDA Rural Development.
Federal tax credits
There is no ADU-specific federal tax credit. ADUs may incidentally qualify for existing federal energy-efficiency and clean-energy tax credits when the ADU construction includes qualifying measures.
Federal housing programs
HUD administers several discretionary programs that can fund ADU-related activity at the grantee's election, but none is an ADU-specific program.
ZIP Codes
- 97201
- 97202
- 97203
- 97204
- 97205
- 97206
- 97208
- 97209
- 97210
- 97211
- 97212
- 97213
- 97214
- 97215
- 97216
- 97217
- 97218
- 97219
- 97220
- 97221
- 97227
- 97230
- 97231
- 97232
- 97233
- 97236
- 97239
- 97266
Post Office
- 101 SW Madison St, 97204
- 1020 SE 7th Ave, 97214
- 2017 NW Vaughn St, 97209
- 2130 N Kilpatrick St, 97217
- 2300 SW 6th Ave, 97201
- 2425 NE 50th Ave, 97213
- 3225 SW 87th Ave, 97225
- 400 SE 103rd Dr, 97216
- 4048 NE 122nd Ave, 97230
- 5010 SE Foster Rd, 97286
- 630 NE Killingsworth St, 97211
- 745 NW Hoyt St, 97208
- 7805 SW 40th Ave, 97219
- 8100 SE Crystal Springs Blvd, 97206
- 815 NE Schuyler St, 97212
- 8420 N Ivanhoe St, 97203
- 8816 SE 17th Ave, 97202