Seattle ADU Plan Review (Land Use + Building)
Plan review is when Seattle actually reads your drawings. Building, land use, fire, and public works reviewers each mark up the plans, then the city issues a consolidated set of correction comments. Most of the calendar time on an ADU permit lives here.
Last verified 2026-05-15
| Typical timeline | 6–10 weeks |
|---|---|
| Direct city fees | $3,000–$8,000 |
| Reviewing department | SDCI |
| Submittal portal | https://cosaccela.seattle.gov/portal/ |
Timeline and fee ranges are project-level averages aggregated from public data and Golden State ADU project history. Authoritative current numbers live in the Seattle published fee schedule and the city's permit portal — verify before budgeting.
What plan review (land use + building) actually means in Seattle
In review, each discipline checks the plans against the code it owns. Building reviewers look at structural, life-safety, egress, and energy code. Land use checks setbacks, height, lot coverage, parking, and ADU-specific zoning standards. Fire looks at access, hydrants, and sprinkler thresholds. Public works looks at right-of-way, driveway, stormwater, and utility connections.
Reviews typically run in parallel, but the slowest discipline sets the schedule. If land use takes 8 weeks and building takes 4, the project is in review for 8 weeks, not 12.
When reviews complete, the city consolidates comments into a corrections package and bounces the project back to the applicant. Almost every ADU permit gets at least one corrections cycle.
SEATTLE NOTE
Seattle uses electronic plan review. Reviewers leave markups directly on the plan set and publish a summary report at the end of each cycle; applicants respond inside the same plan set rather than as a separate document.
Why Seattle plan review (land use + building) hits the high end
- 01Plan completeness at intake — incomplete packages add full review cycles, not just days
- 02Whether the project triggers SEPA, design review, shoreline, or critical-areas review
- 03Reviewer workload at the time of submittal
- 04Whether outside agencies (water/sewer district, fire district, county) are in the review chain
- 05How quickly the applicant returns corrections in later cycles
Where the dollars actually come from
- 01Most cities invoice the bulk of plan review fees after intake based on valuation
- 02Hourly review fees can apply when reviewers spend more than the included hours — check the city's published fee schedule
- 03Re-review hours after multiple corrections cycles are usually billed at the same hourly rate
Exact dollar amounts vary by project. Use the Seattle fee schedule linked below for the current numbers.
Common homeowner mistakes
First reviews almost always produce corrections. Plan calendar and budget for at least one full corrections cycle before issuance.
Submitting architectural plans without structural calculations or WSEC energy compliance forms guarantees a corrections cycle just to add what should have been there.
Public works comments on driveway approach, frontage improvements, or stormwater management are often more disruptive than building comments — and easier to design for early.
Plan Review (Land Use + Building) checklist
These are typical artifacts for an ADU project at this phase in Washington cities. Exact requirements depend on the project and the current Seattle submittal checklist — verify with the city before submitting.
- Designer of record available to issue review-comment responses
- Structural calculations and details
- Washington State Energy Code (WSEC) compliance forms
- Stormwater planRequired for most ADU projects that add impervious surface.
- Geotech reportRequired on steep slopes, fill, or sensitive soils.
- Side-sewer / utility availabilityRequired when adding a new dwelling unit.
When to call a pro
A contractor who has cleared recent Seattle ADU permits knows which reviewer flags what, and can pre-empt the comments that always show up before the package even gets uploaded.
Seattle Plan Review (Land Use + Building) questions
How long does Seattle ADU plan review (land use + building) take?
For an ADU project in Seattle, WA this phase typically runs 6–10 weeks. Complex sites, missing reports, first-time submittals, or busy permit seasons trend toward the upper end. Resubmittals reset the clock for that round. These ranges are project-level averages — verify the current published timeline with Seattle for your specific project.
Go deeper: Read the Seattle Design Review for ADUs: when it applies (2026) guide
What does plan review (land use + building) cost in Seattle?
Direct Seattle fees for this phase typically run $3,000–$8,000. That excludes designer/consultant time, impact fees, side-sewer / utility connection charges, and inspection fees that may apply separately. The authoritative current numbers live in the Seattle published fee schedule.
Go deeper: Read the Seattle Design Review for ADUs: when it applies (2026) guide
Which Seattle department handles plan review (land use + building)?
SDCI handles this phase; submittals and status live in https://cosaccela.seattle.gov/portal/. See Seattle Department of Construction & Inspections (SDCI): https://www.seattle.gov/sdci/permits/common-projects/accessory-dwelling-units.
Go deeper: Read the Seattle Design Review for ADUs: when it applies (2026) guide
What's the most common reason plan review (land use + building) stalls in Seattle?
Incomplete drawings, missing structural/energy/stormwater pages, and corrections returned without a comment-response letter are the usual stall causes in Seattle. We pre-screen every submittal against the current Seattle checklist before it goes to the city.
Go deeper: Read the Seattle Design Review for ADUs: when it applies (2026) guide
Do I need a contractor or designer for Seattle plan review (land use + building)?
Not legally required for owner-applicants, but in Seattle every ADU permit eventually touches building, land use, fire, and public works review tracks. A designer of record is effectively required because review comments are technical and time-bound.
Go deeper: Read the Seattle Design Review for ADUs: when it applies (2026) guide
How do I check Seattle permit status during plan review (land use + building)?
Seattle publishes live status inside https://cosaccela.seattle.gov/portal/. The same record carries application data, review comments, fee balances, and (after issuance) inspection results.
Go deeper: Read the Seattle Design Review for ADUs: when it applies (2026) guide
Seattle permit sources we used
Every claim on this page about Seattle permits, fees, portals, or departments traces to an official city or zoning-code source. Numbers in the at-a-glance table come from our project history and public data; verify current values with the city before budgeting.
- Seattle Department of Construction & Inspections (SDCI) · city pageAccessory Dwelling Unit — SDCI
Defines AADU vs DADU in Seattle, lists the permit types required, and links to current standards.
Accessed 2026-06-03
- SDCI · help articleHow Do You Get a Permit?
Seattle's general permit pipeline: research, pre-app, application, intake, review, issuance, inspections.
Accessed 2026-06-03
- City of Seattle · portalSeattle Services Portal
Official submittal portal for SDCI permits, document uploads, and corrections.
Accessed 2026-06-03
- SDCI · help articleHow to Respond to Review Comments
Seattle's electronic plan-review process and how applicants respond to corrections cycles.
Accessed 2026-06-03
- SDCI · fee schedule2026 Fee Subtitle (Seattle Municipal Code Ch. 22.900) — PDF
Seattle's 2026 fee subtitle — base permit, plan review, and hourly review fees that apply during review.
Accessed 2026-06-03