Everything homeowners ask about building an ADU in Beaverton — answered with 2026 data.
Yes, ADUs are allowed in Any zoning district that allows a single-detached dwelling as the principal use, including residential (R/MR) and several commercial districts (per Ch. 20 land-use tables) in Beaverton, OR. The maximum size for a detached ADU is 800 sq ft or 50% of the primary dwelling's gross floor area, whichever is less. Attached ADUs can be up to 800 sq ft or 50% of the primary dwelling's gross floor area, whichever is less. Beaverton has an ADU-friendliness score of 7/10. Check our full Beaverton ADU rules page for complete zoning details.
ADU construction in Beaverton typically costs $150,000-$320,000. The cost per square foot averages $150-$300. Garage conversions are more affordable at $100,000-$180,000, while prefab ADUs cost $100,000-$240,000. Permit fees add Type 1 application fee plus valuation-based building permit fees (third-party guides estimate $2,500-$9,000) — Confirm with Beaverton Building Division to your budget. See our detailed Beaverton ADU cost guide.
Detached ADUs in Beaverton can be up to 800 sq ft or 50% of the primary dwelling's gross floor area, whichever is less. Attached ADUs are limited to 800 sq ft or 50% of the primary dwelling's gross floor area, whichever is less. Junior ADUs (JADUs) have a cap of N/A (Oregon does not use a JADU category). Maximum height is Per the underlying zone's accessory-structure/dwelling standards — Confirm with Beaverton Planning Division. You are allowed up to 1 ADU per detached dwelling unit on a qualifying lot.
Rear setback: Per underlying zone accessory-structure standards — Confirm with Beaverton Planning Division. Side setback: Per underlying zone accessory-structure standards — Confirm with Beaverton Planning Division. Front setback: Per underlying zone — Confirm with Beaverton Planning Division. Note that garage conversions may be exempt from setback requirements if the existing structure is already within the setback area.
No additional off-street parking may be required (ORS 197.312, SB 1051/HB 2001). Many cities and states have been relaxing ADU parking requirements in recent years. In California, no additional parking is required for ADUs near transit.
Not required — Oregon law prohibits owner-occupancy conditions on ADUs. Note that owner-occupancy rules vary by state law — California and several other states have eliminated this requirement for standard ADUs.
The ADU permit review timeline in Beaverton is typically Commonly 2-4 months total from application to permit issuance — Confirm with Beaverton Planning Division. Plan check: Included in building permit review — Confirm with Beaverton Building Division. Pre-approved plans availability: No city pre-approved plan library — Confirm with Beaverton Planning Division.
Average ADU rental income in Beaverton: 1-bedroom units rent for $1,400-$1,700/month, 2-bedroom units for $1,700-$2,000/month. Short-term rentals: No statewide ban; check Beaverton business-license and any STR requirements — Confirm with the City of Beaverton. Expected ROI: 6-8% annual return.
The minimum lot size for an ADU in Beaverton is No ADU-specific minimum; requires an existing detached dwelling as principal use. This applies to detached ADUs — garage conversions and JADUs may have different or no lot size requirements.
Garage conversions are one of the most popular and affordable ADU options. In Beaverton, a garage conversion typically costs $100,000-$180,000. The key advantages are lower cost (no foundation work), potential setback exemptions, and faster permitting. Read our complete garage conversion guide.
Tell us about your project and we'll connect you with ADU builders serving Beaverton. Free, no obligation — you choose who to work with.
🔒 Your info is secure. We share it only with contractors quoting your project. No spam, no obligation.
Just browsing? Search ADU builders near you by ZIP code.