ADUs are allowed in WilsonvilleTypes:DetachedInternal
Types:DetachedInternal
Accessory Dwelling Unit (ADU) Rules for Wilsonville, OR
Is your property eligible for an ADU?
# of Properties
7,761
Owner-occupied
71%
Zoning districts
23
Avg Home Value
$891,938
Median Lot Size
0.13 acres
Avg Income
$107,444
Residential Types:
7,761 housing units
Single Family
87%
2-3 Family
2%
Apts (4+ units)
3%
Other
8%
Zoning Districts:
8,078 parcels · 23 districts
V
32%(2,573)
PDR3
22%(1,770)
PDR4
10%(794)
PDR5
9%(767)
Other
27%(2,174)
ADU Rules
What can you build in Wilsonville, OR?
Wilsonville, OR follows state and local rules for Accessory Dwelling Units. Here is a concise overview of the local rules.
Eligibility
- –Internal / Attached ADU: By Right
- –Detached ADU: By Right
Interior / Attached ADU Size Limits
- –Maximum habitable floor area of 800 sq ft citywide; 600 sq ft in the Old Town Overlay or Old Town Residential zone.
Detached ADU Size Limits
- –Maximum detached ADU habitable floor area: 600 sq ft in Old Town (OTR zone or “O” Overlay), otherwise 800 sq ft.
Max Units
- –1 ADU per dwelling unit per lot (single-family; attached or detached).
- –Duplex, triplex, quadplex, and multifamily: not permitted.
- –OTR/Old Town Overlay: same limit (1 per dwelling unit per lot).
Owner Occupancy
- –Owner-occupancy not required.
Parking
- –No minimum; no maximum (no limit) for ADU parking. Bicycle parking not required; Village Zone SF-ADU: NR (no requirement).
ADU State Law
What can you build in Oregon?
- –In urban growth areas, Oregon law requires cities and counties to allow at least one ADU on lots zoned for detached single-family homes.
- –Local jurisdictions cannot require owner occupancy for ADUs, but may regulate short-term or vacation rentals.
- –There are no statewide limits on ADU size, height, setbacks, lot size, or floor area ratio. Local zoning rules apply.
- –Parking requirements, if any, are set by the local jurisdiction, subject to state limitations.
- –Some cities may allow more than one ADU per lot, depending on local code.
- –Oregon law does not require counties to allow ADUs in rural residential zones. Whether an ADU is allowed depends on county zoning.
- –ADUs in rural residential areas cannot be used for short-term or vacation rentals.
- –Additional requirements may apply related to wildfire risk, water supply, septic capacity, and fire access.
- –Counties may impose additional restrictions beyond state law or choose not to allow ADUs at all.
- –If a county allows ADUs, state law imposes strict limits, including a minimum 2-acre lot size, a maximum ADU size of 900 sq ft, a location within 100 ft of the primary dwelling, and a limit of one ADU per parcel.
What's allowed on your lot?
These are the municipality-wide rules. What's allowed on a specific property also depends on state laws, setbacks, floor area ratio, lot coverage, environmental constraints, topography, and other property-specific factors. Search your address on FutureLot to see what's allowed on your property.
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ADU rules in other Oregon municipalities
Rules change at the town line. Check the municipality your property is actually in.
Clackamas County