Federal Way ADU Cost
Real Federal Way, WA pricing for detached and attached ADUs across six lot-size bands. Numbers reflect current bids and recent projects, not internet averages.
Last updated 2026-05-15
We're verifying Federal Way's cost data this quarter. Contact us for a current estimate on your specific lot.
Click a lot-size band to compare across cities.
Federal Way ADU pricing questions
What does a typical detached ADU cost in Federal Way?
Federal Way all-in detached ADU pricing varies by lot size and site complexity. Send your address for a same-week range.
What's included in the Federal Way construction line?
Construction in Federal Way is priced separately from design, permits, and site work so you can see exactly where your dollars go.
Why is ADU pricing in Federal Way so different from online averages?
Internet averages mash together every market, lot type, and finish level. Our Federal Way numbers come from current bids and recently completed projects on Puget Sound lots — same trades, same suppliers, same code cycle you'll be building under.
How do I get a firm number for my Federal Way lot?
Send the address. We'll pull zoning, overlays, and utility constraints, walk the buildable envelope, and return a written range tied to your specific parcel — no charge, no obligation. Book it on the contact page.