ADU Permits in City of Issaquah
Rules for detached (DADU) and attached (AADU) accessory dwelling units inCity of Issaquah, 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 City of Issaquah 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 Issaquah offers pre-approved DADU plans; ask the permit center.
City of Issaquah permit-process facts
ADU permit fees
Fee schedule not yet aggregated. Check the City of Issaquah fee schedule directly.
Fee scheduleReview timeline
Typical: 45–120 business days
HB 1337 conformance
City of Issaquah 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 Issaquah’s permit-rules table; per-parcel facts (your specific setbacks, easements, ECA buffers) are pulled live on the parcel page. Primary source: https://issaquah.municipal.codes/LUC/18.500.090. Last verified 2026-05-16.