ADUs are allowed in GastonTypes:Detached
Types:Detached
Accessory Dwelling Unit (ADU) Rules for Gaston, OR
Is your property eligible for an ADU?
# of Properties
266
Owner-occupied
60%
Zoning districts
11
Avg Home Value
$347,640
Median Lot Size
0.19 acres
Avg Income
$130,088
Residential Types:
266 housing units
Single Family
1%
2-3 Family
1%
Apts (4+ units)
3%
Other
95%
Zoning Districts:
293 parcels · 11 districts
R-2
37%(107)
R-3/MHP
26%(77)
R-1
14%(42)
C
9%(27)
Other
14%(40)
ADU Rules
What can you build in Gaston, OR?
Gaston, OR follows state and local rules for Accessory Dwelling Units. Here is a concise overview of the local rules.
Eligibility
- –Internal / Attached ADU: Not addressed in the local bylaw
- –Detached ADU: By Right
Detached ADU Size Limits
- –Maximum size of 750 sq ft for a detached accessory dwelling.
- –Maximum size of 25% of the primary residence floor area for a detached accessory dwelling.
Max Units
- –1 per lot or parcel
Parking
- –1 space/ADU; max 2 spaces (150% of min); exceptions: joint/shared parking may reduce requirements; off-site parking allowed within 200 ft in residential zones.
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.
Check my propertyHow can we help you?
Get matched with trusted local builders
Understand what's allowed on your property
Learn the key rules and size limits for ADUs
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