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ADUs are allowed in Milwaukie
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.

Interior / Attached ADU Size Limits

  • Maximum size of 800 sq ft for an attached or internal accessory dwelling unit

Detached ADU Size Limits

  • Maximum detached ADU structure footprint of 800 sq ft.

Max Units

  • Single detached dwelling: up to 2 ADUs/lot; if 2, max 1 attached/internal.
  • Duplex/triplex/quadplex/townhouse/multifamily: ADUs not allowed.
  • JADU: none specified.

Owner Occupancy

  • Owner-occupancy is not required for ADUs.

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 limited to 95 days/year when unhosted; on properties with an ADU used for short-term rental, either the primary residence or the ADU must be occupied by the owner or a primary operator for at least 270 days/year.

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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Is your property eligible for an ADU?

ADU rules in other Oregon municipalities

Rules change at the town line. Check the municipality your property is actually in.

Clackamas County

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