Beaverton, OR Accessory Structures: Garage Conversions (2026)
Garage conversion rules in Beaverton, OR, sometimes called garage-to-ADU or accessory living unit conversions, govern permits, ceiling height, egress, and parking replacement.
Key Facts
- Method allowed
- Garage conversion permitted for ADU
- Size cap applies
- 800 sq ft (no garage exemption)
- Exempt instead
- Basement, attic, or 2nd-story conversions
- Still required
- State and local building code compliance
Summary
Converting a garage into an accessory dwelling unit is allowed in Beaverton, but unlike a basement or attic conversion it still counts toward the 800-square-foot ADU size cap.
An accessory dwelling unit may be created in the following manner:
1. Conversion of existing living area, attic, basement or garage; [ORD 4782; April 2020]
2. Adding floor area to the primary structure or to an accessory structure, subject to the limitations of the zoning district in which it is located; [ORD 4822; June 2022]
3. Constructing a new detached dwelling or placing a manufactured home on the lot (in either case, the accessory dwelling unit can be internal or detached). [ORD 4822; June 2022]
C. Size [ORD 4782; April 2020]
1. Accessory dwelling units shall not exceed 800 square feet in floor area, except as provided in subsection
2. [ORD 4822; June 2022]
2. Accessory dwelling units that result from the conversion of a level or floor (e.g. basement, attic, or second story) of the primary dwelling are not subject to the size limitations in Section 60.50.03.2.C.1 and may occupy the entire level or floor, provided no new square footage is added through a contemporaneous home renovation. [ORD 4822; June 2022]
3. The floor area measurements are based on what the square footage of the primary dwelling and accessory dwelling unit will be after the accessory dwelling unit is created from the primary dwelling.
Full Breakdown
Development Code 60.50.03.2.B.1 lists conversion of an existing garage as one of the approved ways to create an accessory dwelling unit. The size-cap exemption in 60.50.03.2.C.2, however, applies only to conversions of a basement, attic, or second story: a garage is not on that list, so a garage-conversion ADU is still limited to the standard 800-square-foot cap in 60.50.03.2.C.1. It must also meet the ADU's attachment/separation, easement, and state and local building code requirements.
Violations & Fines
A garage-conversion ADU that exceeds the 800-square-foot cap or skips required building permits is subject to code enforcement and a stop-work order.
Frequently Asked Questions
Can I convert my garage into an ADU in Beaverton?
Does converting my garage avoid the size limit?
Do I still need permits for a garage-conversion ADU?
Sources & Official References
Other rules in Beaverton
Compare Beaverton to another location·View the Oregon accessory structures overview
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Garage Conversions in Nearby Cities
How other cities in Washington County handle garage conversions.