Three counties.
One playbook.
We build DADUs across Pierce, King, and Thurston — Tacoma and Olympia at the anchors, every city in between fair game. Pierce is our home county and the bulk of our work, but our crews permit and pour in Auburn, Federal Way, Kent, Renton, and Seattle's south-end neighborhoods, and we know Thurston's UGAs from Olympia to Yelm by heart. Each county runs its own zoning rulebook — minimum lot size, DADU square-footage cap, and second-unit rights all shift across the line. Below is what to know before you build in each one.
Pierce County
Tacoma. Puyallup. Lakewood. Gig Harbor. University Place. We started here, we live here, we know the planners by name.
DADU rules at a glance
- Owner-occupancy not required (Tacoma 2023; unincorporated Pierce 2024)
- Min lot: 3,750 sf in most R zones
- Max DADU: 1,000 sf or 50% of primary structure
- Setback: 5 ft rear and side
- One DADU per parcel (Tacoma has piloted two in some zones)
- Public sewer effectively required on sub-acre lots
Cities we build in
Tacoma · Puyallup · Lakewood · Gig Harbor · University Place · Fircrest · Steilacoom · Bonney Lake · Sumner · Spanaway · Frederickson · Parkland · South Hill · Edgewood · Milton · Fife · Browns Point · Northeast Tacoma
What makes a Pierce lot work
- Alley access is gold — a rear alley lets us set + service the DADU without cutting through your front yard.
- Public sewer is effectively required on sub-acre lots. Septic-only parcels need a design exception or a sewer tie-in.
- Tacoma pilot zones allow a second ADU — worth checking if you're inside city limits.
- Watch the 50% rule: the DADU can't exceed 1,000 sf or half your main house, whichever's smaller.
- Flat, cleared, rectangular rear yards keep horizontal cost down. Slopes and big trees add site work.
King County
South King focus: Auburn, Federal Way, Kent, Renton. Tukwila and Burien on demand. Rents trend ~10% above Pierce. We absorb the labor premium — same price as Pierce.
DADU rules at a glance
- Two ADUs per lot permitted since 2024 (one DADU + one attached ADU)
- Min lot: 5,000 sf in most R zones
- Max DADU: 1,500 sf (or 1,000 sf in some city codes)
- Setback: 5 ft rear and side
- Owner-occupancy not required in unincorporated King
- Cities vary — Seattle, Renton, Kent each have wrinkles we know
Cities we build in
Auburn · Federal Way · Kent · Renton · SeaTac · Tukwila · Burien · Des Moines · Normandy Park · Covington · Maple Valley · Black Diamond · Newcastle · Vashon · South Park · White Center · Beacon Hill · Rainier Valley
What makes a King lot work
- Two ADUs by right — King is the only county where a second unit is a clean yes, not a pilot. Great for stacking income or a condoized resale.
- City code rules over county: Seattle, Renton, Kent, Auburn each have their own size and parking wrinkles. We confirm the exact jurisdiction before design.
- Watch the 1,500 sf line — above it some cities trigger an exterior firewall. We hold the Rainier at 1,200 to dodge it.
- 5,000 sf minimum lot in most R zones — bigger than Pierce, so check the parcel first.
- Impact fees and SDCs run higher here, but HB 1337 caps them at half the single-family rate.
Thurston County
Olympia. Lacey. Tumwater. Yelm. State-employee tenant base means stable rents. WA HB 1337 fully implemented since 2024 — two ADUs in UGAs.
DADU rules at a glance
- HB 1337 compliant — two ADUs per lot in urban growth areas
- Min lot: 5,000 sf typical (3,500 sf in Olympia LD-II)
- Max DADU: 1,200 sf
- Setback: 5 ft rear and side
- One ADU permitted in rural zones
- Lowest soft costs of our three counties
Cities we build in
Olympia · Lacey · Tumwater · Yelm · Rainier · Tenino · Bucoda · Rochester · Grand Mound · East Olympia · West Olympia · Boston Harbor · Cooper Point
What makes a Thurston lot work
- HB 1337 fully implemented — two ADUs per lot inside urban growth areas (UGAs), no pilot-zone guessing.
- UGA vs rural matters most: inside a UGA you get two units; rural-zoned land is capped at one. Confirm the designation early.
- Olympia's LD-II zone drops the minimum lot to 3,500 sf — the easiest small-lot path in our area.
- 1,200 sf DADU cap — enough for a true 3-bedroom Rainier trim.
- Lowest soft costs of the three counties, and a steady state-employee tenant base keeps vacancy low.
Zoning, at a glance.
We build the same plans, the same way, in all three counties. What changes is the rulebook — minimum lot, how big the DADU can go, and whether a second unit is allowed. Here's the side-by-side.