ADUs are allowed in DurhamTypes:Internal
Types:Internal
Accessory Dwelling Unit (ADU) Rules for Durham, OR
Is your property eligible for an ADU?
# of Properties
410
Owner-occupied
83%
Zoning districts
5
Avg Home Value
$699,707
Median Lot Size
0.23 acres
Avg Income
$149,902
Residential Types:
410 housing units
RES
100%
Zoning Districts:
447 parcels · 5 districts
SDR
91%(407)
OP
5%(23)
IP
1%(6)
NR
1%(6)
Other
1%(5)
ADU Rules
What can you build in Durham, OR?
Durham, 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: Not permitted
Interior / Attached ADU Size Limits
- –Maximum size of 600 sq ft for an internal/attached in-home apartment.
- –Maximum size of 33% of the primary residence’s habitable area for an in-home apartment.
- –With an approved Adjustment, maximum size may increase by up to 10% over 600 sq ft (up to 660 sq ft).
- –With an approved Adjustment, maximum size may increase by up to 10% over the 33% cap (up to 36.3% of habitable area).
Parking
- –0 spaces per ADU; no off-street parking required; garage conversions allowed; Section 3.7 standards apply to any provided parking/access; applies citywide.
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.
Washington County