ADU & DADU Permit Costs in Seattle, by Neighborhood

What accessory dwelling units really cost to permit across Seattle, pulled from real City of Seattle SDCI permit records. Pick a neighborhood for its cost breakdown, plan-review timeline, and recent projects.

Figures are permit-valuation basis (what applicants reported to the City), which typically understates true retail cost. For fees and whether your project needs a permit, see our Seattle permit cost guide.