Accessory Structures in Beaverton, OR

If you live in Beaverton or are thinking about moving there, accessory structures are one of those things you probably won't think about until they affect you directly. Beaverton has 5 specific rules on the books covering different aspects of accessory structures, and some of them might surprise you.

ADU Owner Occupancy

A recorded Beaverton HOA covenant or CC&R cannot require an accessory dwelling unit to be owner-occupied. Development Code § 10.18.4 makes every such recorded instrument print a notice that any clause doing so is unenforceable.

Key details: State law: Ch. 639, Oregon Laws 2019. HOA may NOT: Require ADU owner-occupancy. Notice required: First-page, all-caps statement. Violating clause: Unenforceable by law.

An HOA or CC&R clause requiring owner-occupancy of an ADU is unenforceable under § 10.18.4; recording an instrument that omits the required notice can itself be a code compliance problem for the association.

The rules around adu owner occupancy in Beaverton lean permissive, but that does not mean anything goes.

Tiny Homes

Beaverton has not adopted Appendix Q's special tiny-house standards, so a tiny house here must meet the same full Residential Specialty Code requirements as any other dwelling.

Key details: Governing section: BC 8.02.160. Appendix Q status: Not adopted / preempted. Applicable standard: Full Residential Specialty Code. Scope: Beaverton city limits only.

Building a tiny house that does not meet standard Residential Specialty Code requirements is handled as a building code violation under BC 8.02.120: civil penalty up to $250, each day separate, with authority to stop work.

This is one of the stricter rules in Beaverton's municipal code. If you are unsure whether your situation complies, it is worth checking with the city before proceeding.

Shed & Carport Rules

Beaverton caps combined accessory-structure footprint at 500 square feet on lots up to 10,000 square feet (700 on larger lots), limits height to 15 feet and one story, with 3- to 5-foot setbacks.

Key details: Size cap: 500 sq ft (700 on lots >10,000 sq ft). Height cap: 15 ft, one story max. Setback ≤8 ft tall: 3 ft from lot line. Setback 8-15 ft tall: 5 ft from side/rear lot line. Location limit: No sheds in required front yard.

Sheds exceeding the size, height, or setback limits are treated as unpermitted accessory structures and subject to code enforcement, including possible removal.

Garage Conversions

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.

Key details: 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.

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.

ADU Rules

Beaverton allows one accessory dwelling unit per single-detached home through a staff-level Type 1 permit, capped at 800 square feet unless it converts existing floor area.

Key details: Permit type: Type 1 (Director decision). Max new floor area: 800 sq ft. Conversion exception: No cap if converting existing floor. Required with: One single-detached dwelling. Detached ADU setback option: 5 ft if ≤15 ft tall.

Building without an approved ADU application, or exceeding the 800-square-foot cap outside the conversion exception, is a Development Code violation; the Director can deny, condition, or revoke the permit.

The Bottom Line

Beaverton's accessory structures rules are a mixed bag. Some areas are strict, others are relaxed, and the details matter. The best approach is to check the specific rule that applies to your situation rather than assuming Beaverton is broadly strict or permissive.

These rules come from Beaverton's publicly available municipal code. For complete penalty schedules, exemption details, and answers to common questions, see the individual ordinance pages throughout this guide.