ADU Permits in Woodinville

Rules for detached (DADU) and attached (AADU) accessory dwelling units in Woodinville, King County.

Free lookup. We’ll resolve your zoning, setbacks, and which ADU types are allowed on your specific parcel.

Choose an ADU type for your parcel

State law (RCW 36.70A.681) requires Woodinville to allow two ADUs on a lot in a single-family zone — one attached and one detached, two attached, or two detached — except on lots with critical areas or their buffers. An address’s own page checks its lot’s zoning.

DADU — Detached

Backyard cottage with its own foundation and roof. Most flexibility on layout.

See DADU rules in Woodinville

AADU — Attached

Part of the house or built onto it: a converted basement or garage, or an addition.

See AADU rules in Woodinville

Pre-approved plans

None in Woodinville on Washington Commerce’s statewide list of pre-approved plan programs (November 2026): an ADU here is drawn for its lot.

The state’s list

Woodinville permit-process facts

Permit department

Submit through the Woodinville permit portal.

Permit portal

ADU permit fees

Set by the Woodinville fee schedule.

Fee schedule

Review timeline

Not published by Woodinville.

HB 1337 conformance

Woodinville permits at least two ADUs per single-family lot, with no owner-occupancy requirement and parking limits that respect the HB 1337 ceilings.

Building code: 2021 IBC w/ WA amendments · Residential: 2021 IRC w/ WA amendments · Energy (WSEC): 2021 WSEC

These are Woodinville’s ADU rules as Kolmo reads them; an address’s own page adds its setbacks, easements and critical-area buffers. Source: codepublishing.com, last verified 2026-11-07.

ADU permits in Woodinville — FAQ

Does Woodinville allow detached ADUs (DADUs)?

Yes. Washington's HB 1337 (RCW 36.70A.681) requires Woodinville to allow at least two accessory dwelling units on a lot in a single-family zone within the urban growth area, attached or detached in any combination, except on lots with critical areas or their buffers.

What is the maximum ADU size in Woodinville?

State law bars a city from setting a maximum ADU size below 1,000 sq ft of gross floor area (RCW 36.70A.681(1)(f)). Woodinville's own maximum may be higher — the per-parcel page shows it with the city's code citation.