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ADU design and permits in Seattle

We draw the plans or adapt a pre-approved design, then manage plan check until the permit is issued.

Floor plan drawing with symmetrical rooms on pale green paper

What goes into a permit set?

A survey-based site plan
Architectural drawings
Structural and energy design
Any planning forms the city requires before building review

White kitchen cabinets above a counter with a framed print

Custom or pre-approved plans?

A pre-approved design is faster to permit when it fits the lot. When it does not, a custom plan avoids forcing the yard to fit the drawing.

How long does review take?

Washington has no fixed ADU review deadline like California's. SDCI review time depends on the project and how quickly corrections come back. A pre-approved DADU plan can shorten design and review.

Seattle permits

ADU permits go through the Seattle Department of Construction and Inspections and the Seattle Services Portal. The city also publishes pre-approved DADU plans that can shorten design.

Is your lot ready for an ADU?

Send your address and a sentence about what you want. We look up the zoning, setbacks and utility routes and reply with the ADU types that fit.

We build in Seattle, WA.