Choose an ADU type for your parcel
State law (RCW 36.70A.681) requires City of Bellevue 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. The per-parcel canvas checks your specific zoning.
DADU — Detached
Backyard cottage with its own foundation and roof. Most flexibility on layout.
AADU — Attached
Basement, garage, or addition conversion inside the primary residence footprint.
Standard Plan
Kolmo has not checked whether City of Bellevue offers pre-approved DADU plans; ask the permit center.
City of Bellevue permit-process facts
ADU permit fees
Fee schedule not yet aggregated. Check the City of Bellevue fee schedule directly.
Fee scheduleReview timeline
Typical: 21–90 business days
HB 1337 conformance
City of Bellevue permits at least two ADUs per single-family lot, with no owner-occupancy requirement and parking limits that respect the HB 1337 ceilings.
Rules above are aggregated from City of Bellevue’s permit-rules table; per-parcel facts (your specific setbacks, easements, ECA buffers) are pulled live on the parcel page. Primary source: https://bellevuewa.gov/ADU-reform. Last verified 2026-09-24.
