ADU / DADU permits in City of Bellevue: fees, timeline & requirements (2026)
Everything you need to know about pulling a ADU / DADU permit in City of Bellevue, Washington — when one is required, what it costs, how long review takes, what documents are required, and which inspections you can expect. Cited to Bellevue Development Services.
Permit required?
Yes — see threshold below
Permit fee
Full Construction Permit (Addition/Alteration) fees. Sewer capacity charges may apply (King County: ~$8k-$10k). Apply via https://mybuildingpermit.com.
Review timeline
21–90 days
When does a ADU / DADU need a permit in City of Bellevue?
WA HB 1337 (effective 2024) requires cities ≥6,000 pop. to allow 2 ADUs per lot in residential zones, max 1,000 sq ft, no owner-occupancy requirement, no parking requirement near transit. Local size + design caps apply.
Required submittals
- full architectural plans
- structural calcs
- WSEC compliance form
- site plan w/ setbacks
- sewer/water capacity certification
Inspection sequence
- footing
- foundation
- framing
- rough-in (electrical/plumbing/mechanical)
- insulation
- drywall
- final
Contractor specialties needed
general, electrical-01-or-02, plumbing, mechanical
Notes & caveats
Bellevue allows ADU + DADU per WA HB 1337. Permit via MyBuildingPermit.com.
How to apply
- 1. Confirm your parcel's zoning & overlays. Run an address lookup on the main permits page — we'll pull your specific lot polygon, zoning, setbacks, and any shoreline/ECA/historic overlays.
- 2. Assemble submittals (5).
- 3. Submit through the city portal: Bellevue Development Services ↗
- 4. Track review (typical: 21–90 days). Respond to reviewer comments promptly.
- 5. Pay issuance fees (Full Construction Permit (Addition/Alteration) fees. Sewer capacity charges may apply (King County: ~$8k-$10k). Apply via https://mybuildingpermit.com.) and pick up the permit. Inspection card travels with the job.