ADUs are allowed in MilwaukieTypes:DetachedInternal
Types:DetachedInternal
Accessory Dwelling Unit (ADU) Rules for Milwaukie, OR
Is your property eligible for an ADU?
# of Properties
7,544
Owner-occupied
72%
Zoning districts
17
Avg Home Value
$696,642
Median Lot Size
0.18 acres
Avg Income
$92,220
Residential Types:
7,544 housing units
Single Family
90%
2-3 Family
3%
Apts (4+ units)
3%
Other
4%
Zoning Districts:
7,863 parcels · 17 districts
R-MD
83%(6,555)
R-HD
8%(663)
DMU
2%(165)
MUTSA
1%(86)
Other
5%(394)
ADU Rules
What can you build in Milwaukie, OR?
Milwaukie, 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 of 800 sq ft for an attached/internal ADU, except no maximum when converting a basement of a primary dwelling that has existed on the site for at least 5 years.
Detached ADU Size Limits
- –Maximum detached ADU floor area of 800 sq ft
- –With a variance, maximum detached ADU floor area may increase by up to 25%
Max Units
- –Up to 2 ADUs per lot for a single detached dwelling; if two are provided, only one may be attached to or within the primary structure (the second must be detached). Two detached ADUs are allowed.
- –Duplex, triplex/quadplex, and multifamily: ADUs are not allowed (ADU approval requires the primary use to be a single detached dwelling).
Owner Occupancy
- –No owner-occupancy requirement
Parking
- –No minimum; no maximum for ADUs (Table 19.605.1). Off-street parking, if provided, must meet general residential standards in §19.607.1.
Rental Restrictions
- –Short-term rentals allowed with limits: owner/primary-operator must occupy either dwelling for at least 270 days/year; unhosted STRs limited to 95 days/year; no more than two rental parties at a time; only one STR may operate on a property in low-density zones. No additional long-term rental restrictions stated.
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