We design, permit and build detached DADUs, attached ADUs and home additions across King County — for rental income, for family, for long-term value. Before you spend a dollar, we check your lot against zoning, critical areas and utilities — free.
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Licensed WA general contractor · ELEVAPL755NL · Bonded & insured · Bellevue & Greater Seattle
A DADU is a detached accessory dwelling unit — a separate little cottage on your own lot. An AADU is the same idea attached to your house or built into a garage. Under Washington's HB 1337 (RCW 36.70A.680), cities within urban growth areas — which covers nearly all of our service area — must allow up to two ADUs per lot in addition to your house, at a minimum of 1,000 sq ft and no owner-occupancy requirement — so you can rent out both units long-term (short-term rental rules vary by city). And many cities go bigger: Seattle, Bellevue and much of the Eastside now allow a detached DADU up to 1,200 sq ft (Bellevue at 24 ft tall, LUC 20.20.120). What actually fits your lot is exactly what the free feasibility study confirms.
Home additions are the third thing we build here: expanding your existing house — a new room, a second story, a bigger kitchen. An addition grows your home rather than creating a separate dwelling, so the ADU-specific rules (renting it out, selling it separately) don't apply — but the feasibility, permitting and build process is the same, and it still starts with a free lot review.
Every lot is different — but almost every ADU we build comes down to one of these three. The free feasibility study tells you which one your lot can deliver.
Backyard units on the Eastside typically ask $1,800–$3,500/mo in long-term rent, and state law lets you rent out both your home and the ADU. What yours could earn depends on size, location and finish — the study gives you a real picture. Typical asking rents, not a projection.
Independent living for parents or adult kids — their own front door, kitchen and bathroom, just steps from home. The same idea works as an addition when you'd rather grow the house you're in.
An ADU can add six figures to resale value — appraisers and lenders now count them. And Washington law now allows ADUs to be sold separately as condominiums in many cases; the process and cost depend on your city. Market data, not a projection or financial advice.
One licensed crew from the first lot check to the final walk-through — no handoffs between a designer, a permit expediter and a builder who've never met.
A desktop check of zoning, setbacks, critical areas, trees, easements and utilities. You get a written verdict — what fits and what drives the cost — before spending anything.
Survey, title and city and utility confirmations — we verify on the ground what the desktop study flagged, so there are no surprises later.
Architectural, structural and MEP drawings, energy-code report, full submission and correction handling — one flat design-and-permitting fee for a standard detached ADU. After you sign, you work with our architects directly; we manage the process. See the flat-fee estimate →
One dedicated crew builds it, finished in the James Hardie fiber-cement siding we already specialize in.
A room-by-room punch list, then move-in — backed by our written workmanship warranty.
Typical timing: design about two months · permit review two to six months depending on your city (unincorporated King County ~2 months; a custom Seattle DADU toward the top of the range) · construction four to ten months. Review times are set by your city and outside any builder's control — these are typical ranges, not promises.
“Appears feasible — subject to verification.”
That's what a feasibility study looks like: your lot run against the zoning code and every King County GIS critical-area layer, ending in a plain-English verdict — never a bare yes or no, but "appears feasible, subject to verification," with the exact list of what to confirm next. The photo is our own crew's exterior work — the Hardie fiber-cement finish that goes on every home we build.
The same end-to-end process as the big Seattle DADU firms — from a leaner company, with the owner still on the phone.
We check whether your lot works before you pay for anything. If it doesn't pencil, you'll know — and it costs you nothing.
You know the number before you commit. City fees, surveys and city-required studies are itemized separately — nothing buried.
A small team means the people who priced your project are the ones building it — no sales layer between you and the builder.
We finish every home in James Hardie fiber-cement siding — the exterior standard that clears the strictest city material rules for ADUs.
No pressure — clear answers about your lot, your city's rules and what a build involves.
Get my free feasibility study → (425) 394-8849Send your address and we'll run the free feasibility study — a written verdict on what fits, what drives the cost, and what could bite. No obligation.
We'll reply within one business day. Need to talk sooner? Call (425) 394-8849.
