Redmond ADU Cost
Real Redmond, 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
| Cost category | Under 3,000 sqft | 3,000–3,999 sqft | 4,000–4,999 sqft | 5,000–6,999 sqft | 7,000–9,999 sqft | 10,000+ sqft |
|---|---|---|---|---|---|---|
| All-in (DADU) | $288k–$420k | $326k–$480k | $364k–$540k | $402k–$600k | $440k–$660k | $478k–$720k |
| DADU construction | $255k–$375k | $290k–$430k | $325k–$485k | $360k–$540k | $395k–$595k | $430k–$650k |
| AADU conversion | $162k–$248k | $184k–$286k | $206k–$324k | $228k–$362k | $250k–$400k | $272k–$438k |
| Design & engineering | $9,000–$20,500 | $10,000–$23,000 | $11,000–$25,500 | $12,000–$28,000 | $13,000–$30,500 | $14,000–$33,000 |
| Permit & city fees | $6,800–$14,200 | $7,600–$16,400 | $8,400–$18,600 | $9,200–$20,800 | $10,000–$23,000 | $10,800–$25,200 |
Click a lot-size band to compare across cities.
Redmond ADU pricing questions
What does a typical detached ADU cost in Redmond?
On a 5,000–7,000 sqft lot in Redmond, WA, an all-in detached ADU runs $402k–$600k including design, permits, site work, and construction. Larger or constrained lots shift the number up; we publish the full lot-size matrix above.
What's included in the Redmond construction line?
Construction in Redmond is priced separately from design, permits, and site work so you can see exactly where your dollars go.
How much do design and permits add in Redmond?
Redmond design typically runs $12,000–$28,000, with permit and review fees of the city's published schedule on a 5–7k lot. Both scale with project size and review complexity.
Why is ADU pricing in Redmond so different from online averages?
Internet averages mash together every market, lot type, and finish level. Our Redmond 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 Redmond 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.