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Building an ADU in Beaverton

City code and Oregon law · Last reviewed October 10, 2026

Beaverton allows an accessory dwelling unit (ADU) with a single-detached house in its residential zones. An ADU can be up to 800 square feet, though converting a whole basement, attic or upper floor of the house isn't limited by that cap. The city requires no minimum parking, and the ADU land use application is free. The Planning Director decides it through the city's Type 1 process, and then you get building permits. [1][2][3][4][5]

Beaverton at a glance

ADUs per lot
One, with a single-detached dwelling Adding a third unit makes the project a triplex [1][6]
Where allowed
Listed as a permitted use in the MR, RMA, RMB and RMC residential zones Must go with a single-detached dwelling [1][2]
Max size
800 sq ft No cap when converting a whole level of the house (basement, attic or second story) [1]
Rear setback
5 ft for a one-story ADU no taller than 15 ft Otherwise the zone's rear setback (15 ft in RMA, RMB and RMC) [1][7]
Separation
Attached to the house, or at least 6 ft from the house and other structures [1]
Parking
No minimum parking required [3][9]
Owner occupancy
Cannot be required (state law), except for vacation rentals [9]
Land use application fee
No charge (Planning Division fee schedule, effective 2/1/26 to 1/31/27) [4]
Review
Type 1 decision by the Director, within 120 days of a complete application [5][11]
Easements
An ADU can't be built over an easement [1]
On this page
  1. At a glance
  2. What you can build in Beaverton
  3. Size, setbacks and placement
  4. Parking
  5. Owner occupancy and rentals
  6. Fees and review time
  7. Garage and basement conversions
  8. Middle housing as an alternative
  9. Permit steps
  10. Who to call
  11. Questions people ask

What you can build in Beaverton

Beaverton's ADU rules are in Development Code Section 60.50.03. An ADU "is permitted only in conjunction with a single-detached dwelling." The code defines it as "An additional dwelling unit on the same lot as a single-detached dwelling," inside or attached to the house, in a detached building, or a manufactured home.

You can create an ADU by:

ADUs are a permitted use in the MR, RMA, RMB and RMC residential zones. If you add a second unit that also fits the definition of a duplex, you can choose which to apply for. Adding a third unit makes the project a triplex. See our Oregon ADU law page for the state rules. [1][2][6]

Size, setbacks and placement

Size. ADUs "shall not exceed 800 square feet in floor area." The cap doesn't apply when you convert a whole level or floor of the house, such as a basement, attic or second story, as long as you don't add new square footage in a renovation at the same time. ADUs added to a house that existed on June 30, 2022, don't count toward floor area ratio limits.

Placement. An ADU must be attached to the house or be at least 6 feet from the house and other structures on the lot. It can't be built over any easement. An ADU made by adding floor area to an accessory structure needs its own exterior entrance.

Setbacks. The zone's setbacks apply, except that a one-story ADU no taller than 15 feet from finished grade "may be located 5 feet from the rear property line." In the RMA, RMB and RMC zones, the standard front setback is 10 feet and the rear setback is 15 feet, and the maximum building height is 40 feet in RMA and 35 feet in RMB and RMC, with extra height limits in some areas. The city says side setbacks in these zones range from 0 to 5 feet depending on the situation, so confirm yours with the Planning Division. [1][7][8]

Parking

Beaverton's code says "No minimum parking is required for any use." Oregon law also says reasonable local rules for ADUs can't include "requirements to construct additional off-street parking," except for vacation rentals.

The city's middle housing web page says off-street parking is "generally required when new homes are added (up to one parking space per unit maximum)." The current code section, Section 60.30.10, says "No minimum parking is required for any use," so confirm with the Planning Division before you design around parking. [3][8][9]

Owner occupancy and rentals

Oregon law says cities can't require you to live in the house or the ADU. The exception is vacation rentals: cities may require owner occupancy or off-street parking for ADUs used as "vacation occupancies." Ask the city about any rules for short-term rentals before you list the unit. [9]

Fees and review time

The ADU land use application is "No Charge" on the city's Planning Division fee schedule in effect from February 1, 2026, to January 31, 2027. Building and site development fees still apply, and the city lists their fee schedules on its fee information page.

The ADU application uses the Type 1 procedure. The Director must approve, approve with conditions, or deny a Type 1 application within 120 calendar days after it is complete. A Type 1 decision can be appealed within 12 calendar days of the notice. For budgeting, see our ADU cost guide. [4][5][10][11]

Garage and basement conversions

Converting a garage, attic or basement is one of the listed ways to create an ADU. Converting a whole level of the house, such as a basement or second story, is exempt from the 800-square-foot cap if you don't add space at the same time. See our garage conversion guide for the general steps. [1]

Middle housing as an alternative

Beaverton's lower-density RMA, RMB and RMC zones also allow duplexes, triplexes, quadplexes, townhomes and cottage clusters. Each middle housing unit can be put on its own lot through a middle housing land division. ADUs aren't allowed on child lots created by a middle housing land division. [2][8][12]

Permit steps in Beaverton

  1. Check your zone and lot

    Find your zone and confirm you have a single-detached house. Call the Planning Division's zoning help line at 503-526-2420 or email MailboxCDDPlanning@beavertonoregon.gov. [13][14]

  2. Design within the ADU rules

    Keep the ADU to 800 square feet unless you're converting a whole level, keep 6 feet from other buildings if detached, and stay off easements. A one-story ADU up to 15 feet tall can sit 5 feet from the rear lot line. [1]

  3. Apply for the ADU land use approval

    The property owner or an authorized agent files an Accessory Dwelling Unit application on the city's form. There is no Planning fee. The Director reviews it under the Type 1 procedure. [4][5]

  4. Apply for building permits in BEPS

    All applications are processed electronically through the Beaverton Electronic Permitting System (BEPS). Call the Building Division at 503-526-2403 with questions about when building permits are needed. [13][15]

  5. Pay fees and pass inspections

    Pay permit fees and request inspections through BEPS as the work goes on. [15]

Who to call

Questions people ask

How big can an ADU be in Beaverton?

Up to 800 square feet of floor area. If you convert an entire level of your house, such as a basement, attic or second story, the cap doesn't apply, as long as you don't add new square footage at the same time. [1]

How many ADUs can I have in Beaverton?

One, with a single-detached house. The code defines an ADU as an additional unit on the same lot as a single-detached dwelling, and adding a third unit makes the project a triplex. [1][6]

How close to the property line can a backyard ADU be in Beaverton?

A one-story ADU no taller than 15 feet can be 5 feet from the rear property line. Otherwise the zone's setbacks apply, such as a 15-foot rear setback in RMA, RMB and RMC. A detached ADU must also be 6 feet from other buildings. [1][7]

Do I need parking for an ADU in Beaverton?

No. Beaverton's code has no minimum parking requirement for any use, and Oregon law bars cities from requiring extra off-street parking for ADUs except vacation rentals. [3][9]

How much does the ADU application cost in Beaverton?

The Planning Division's ADU application is free under the fee schedule in effect through January 31, 2027. Building permit and other fees still apply. [4][10]

Sources (15)
  1. Beaverton Development Code 60.50.03 Accessory Dwelling Unit (effective 1/2/2025), City of Beaverton (enCodePlus). Accessed October 10, 2026.
  2. Beaverton Development Code 20.05.20 Land Uses (Residential Zoning Districts), City of Beaverton (enCodePlus). Accessed October 10, 2026.
  3. Beaverton Development Code 60.30.10 Number of Parking Spaces, City of Beaverton (enCodePlus). Accessed October 10, 2026.
  4. Planning Division Fee Schedule, effective 2/1/26 – 1/31/27, City of Beaverton Community Development Department. Accessed October 10, 2026.
  5. Beaverton Development Code 40.05.15 Accessory Dwelling Unit Application, City of Beaverton (enCodePlus). Accessed October 10, 2026.
  6. Beaverton Development Code Chapter 90 Definitions (Dwelling Types), City of Beaverton (enCodePlus). Accessed October 10, 2026.
  7. Beaverton Development Code 20.05.15 Site Development Standards, City of Beaverton (enCodePlus). Accessed October 10, 2026.
  8. Middle Housing in Lower Density Neighborhoods, City of Beaverton Planning Division. Accessed October 10, 2026.
  9. ORS 197A.425 Accessory dwelling units, Oregon State Legislature. Accessed October 10, 2026.
  10. Fee Information, City of Beaverton Community Development Department. Accessed October 10, 2026.
  11. Beaverton Development Code 50.35 Type 1, City of Beaverton (enCodePlus). Accessed October 10, 2026.
  12. Beaverton Development Code Chapter 40 Applications (date printed September 17, 2025), City of Beaverton. Accessed October 10, 2026.
  13. Planning, City of Beaverton Community Development Department. Accessed October 10, 2026.
  14. Welcome to Beaverton's Development Code, City of Beaverton (enCodePlus). Accessed October 10, 2026.
  15. Apply for Permits, City of Beaverton Community Development Department. Accessed October 10, 2026.

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