ADUs are allowed in West LinnTypes:DetachedInternal
Types:DetachedInternal
Accessory Dwelling Unit (ADU) Rules for West Linn, OR
Is your property eligible for an ADU?
# of Properties
10,547
Owner-occupied
76%
Zoning districts
20
Avg Home Value
$795,379
Median Lot Size
0.23 acres
Avg Income
$155,128
Residential Types:
10,547 housing units
Single Family
89%
Apts (4+ units)
1%
Other
9%
Zoning Districts:
10,799 parcels · 20 districts
R10
57%(6,199)
R7
12%(1,250)
R2.1
9%(949)
R5
7%(746)
Other
15%(1,655)
ADU Rules
What can you build in West Linn, OR?
West Linn, 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 size for an internal/attached ADU: 1,000 sq ft.
Detached ADU Size Limits
- –Maximum size of 1,000 sq ft for a detached ADU.
- –Maximum size of 75% of the gross square footage of the primary dwelling for a detached ADU.
Max Units
- –1 ADU per lot for single-family detached (ADU can be attached or detached).
- –0 ADU per lot for duplex, triplex, quadplex.
- –No limit stated for multifamily/townhouses.
Parking
- –No ADU min or max; max is based on similar land use per CDC 46.090(A)(3); off-street parking for a single-family dwelling must be on the same lot (CDC 46.070(A)).
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