If you own a home in Everett, an ADU is likely the highest-return square footage you can add. Here’s what it costs in 2026 — with real numbers, not ranges designed to hide the answer.
The short answer
Garage conversions run $150–$300 per sq ft ($80,000–$180,000 typical). Detached backyard cottages (DADUs) run $300–$500 per sq ft — a 750 sq ft cottage lands around $225,000–$375,000 all-in, plus design (8–12%) and Everett permit fees ($5,000–$15,000).
Why detached costs more per foot
A DADU concentrates a full house’s systems — kitchen, bath, HVAC, water heater — into a small footprint. Systems don’t scale down with square footage, so the per-foot rate rises. The tradeoff: maximum privacy and the strongest rents.
The rental math in Everett
Everett one-bedroom ADUs rent around $1,400–$1,900/mo, two-bedrooms $1,800–$2,300/mo. A $250,000 cottage renting at $1,800/mo generates ~$21,600/yr gross — often covering financing while you build equity. And with HB 1337, you can even sell the ADU separately via condo declaration.
Your next step
Get a free lot check: we confirm what your Everett lot allows, sketch what fits, and give an honest budget range. Call 425-341-5430