ADU Permit Fees & Costs in Seattle, Washington
Everything you need to apply for a adu permit in Seattle, Washington — documents, fees, steps, and a downloadable submission packet.
Key Facts
- Permit required
- Yes
- Submission method
- Online
- Typical fee range
- $7,500 – $24,750
- Review time
- Varies by jurisdiction
- Inspections
- 6 inspections required
Limited Data Available
Some information on this page has not been fully verified. We're working to improve data quality. Always verify with Seattle directly.
Estimated Total Fees
$7,500 – $24,750
Range based on typical residential solar PV system. Actual fees depend on project valuation and system size.
| Fee Component | Range | Confidence |
|---|---|---|
| ADU Permit Fee[1][2] Master Use Permit and building permit fees based on valuation. Seattle progressive DADU (Detached ADU) policies allow relaxed parking requirements in many zones. | $5,000 – $15,000 | ✓ |
| Plan Review Fee[3][4] Plan review fee is typically 50-65% of the permit fee. | $2,500 – $9,750 | ✓ |
| Estimated Total | $7,500 – $24,750 |
Fees shown as ranges. Always verify the exact amount with Seattle before submission. Additional fees may apply for expedited review or resubmittals.
Generate your permit packet
Get a personalized ADU permit packet for Seattle, Washington — tailored to your project details.
- Required forms: Master Application and Permit, and more
- Pre-filled templates: Permit Cover Sheet
- Fee breakdown: $2,500–$15,000 estimated total
- Step-by-step Seattle SDCI portal submission guide
- Inspection prep checklist (6 items)
- Personalized for your specific project details
Free to preview · Pro to download
Required Documents
Seattle requires the following documents for this permit application.
Master Application and Permit
Completed Seattle Master Application (Master Use Permit) for ADU/DADU projects
Architectural Plans
Architectural drawings prepared by Washington licensed architect including floor plans, elevations, sections, and building details
Site Plan
Site plan showing lot boundaries, setbacks, building location, parking, open space, and access ways
Structural Plans and Calculations
Structural design sealed by Washington licensed structural engineer
Utility System Plans
Utility connection plans for water, sewer, electric, gas, and separate metering details
Geotechnical Report (if required)
Geotechnical investigation report if site conditions warrant or foundation type requires
Permit Process
Follow these steps to submit your permit application through Seattle SDCI.
- 1
Pre-Design Review
Attend neighborhood consultation meeting and verify zoning compatibility for ADU/DADU
- 2
Master Use Permit Application
Submit Master Use Permit application with all architectural, structural, and utility plans
You'll need: Master Application and Permit, Architectural Plans, Site Plan, Structural Plans and Calculations, Utility System Plans
- 3
Master Use Permit Review
SDCI reviews application for compliance with Seattle Municipal Code and Land Use Code
- 4
Address Comments and Revisions
Submit revised plans addressing reviewer comments and conditions
- 5
Building Permit Issuance
Transition to building permit phase and pay permit fees
- 6
Construction with Inspections
Perform construction with required inspections at key phases
- 7
Final Certificate of Occupancy
Receive final inspection approval and occupancy certificate
Authority Sources
Data on this page is sourced from official records published by the permitting authority. Always verify requirements directly before submitting.
Verified February 15, 2026
Verified February 15, 2026
Verified February 15, 2026
Frequently Asked Questions
- Do I need a adu permit in Seattle?
- Yes. Seattle requires a adu permit for this type of project. Submitting without a permit may result in fines, required removal, or complications when selling your property.
- How long does adu permit approval take in Seattle?
- Processing times in Seattle vary depending on project complexity and current review volume. The process involves 7 steps. Contact Seattle Development Services for current timelines.
- What documents are required for a adu permit in Seattle?
- Seattle requires 6 documents including Master Application and Permit, Architectural Plans, Site Plan, Structural Plans and Calculations, and others. See the full list above for details.
- What happens if I build without a adu permit in Seattle?
- Building without a permit in Seattle can result in stop-work orders, fines, required removal of work, difficulty selling your property, and insurance complications. It is strongly recommended to obtain proper permits before starting work.
- Can PermitMagic help prepare my adu permit submission in Seattle?
- Yes. PermitMagic generates a submission-ready packet tailored to Seattle's requirements, including a document checklist, workflow steps, and authority references. Start a permit plan to get your personalized packet.
- How much does a adu permit cost in Seattle?
- ADU permit fees in Seattle typically range from $7,500 to $24,750, depending on project scope. Fees may include building permit, plan review, and technology surcharges. Verify current fees with Seattle.
Related Permits
Other permits in Seattle
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Answer a few project questions and get a adu permit packet for Seattle, Washington — with every document, form, and fee organized for submission.
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