Single-story detached ADU with gray siding and a blue front door built by Doyle Construction

ADU & DADU Construction

ADUs built to the same standard as our custom homes

More home on the land you already own: detached ADUs, attached units, and garage conversions across Thurston and Pierce counties.

Why an ADU, why now

Washington changed the rules. Your lot got more valuable.

Washington's ADU legislation opened the door for second dwellings on most residential lots, and South Sound cities have been updating their codes to match. That makes an ADU one of the highest-leverage projects a homeowner can build: space for family now, rental income later, and resale value either way.

Doyle builds ADUs with the same crew, the same building science, and the same turn-key pricing as our custom homes. Small building, same standard.

Detached ADUs (DADUs)

Stand-alone backyard homes with maximum privacy and flexibility, the workhorse of rental and family setups.

Attached ADUs

Units integrated into your existing home, sharing a wall but living independently.

Garage conversions

A new garage with living space above or beside it, or converting what you have into a legal dwelling.

Accessible units

As Certified Aging in Place Specialists, we design ADUs that work for aging parents and mobility needs from day one.

Single-story ADU with light blue siding and a blue front door built by Doyle Construction
Open-concept living room and kitchen inside an accessory dwelling unit by Doyle Construction

Straight answers

ADU questions, answered plainly

What is an ADU, and what can I use it for?

An accessory dwelling unit is a second, self-contained home on the same lot as your main house. Owners use them for aging parents, adult kids, guests, home offices, and rental income. Washington's recent ADU legislation made them dramatically easier to permit in most cities.

How much does an ADU cost to build in Thurston or Pierce County?

It depends on size, whether it's detached or attached, and site utilities (sewer or septic, water, power). We produce a complete budget during pre-construction before you commit. Be skeptical of per-square-foot numbers quoted without seeing your site.

What are the ADU rules in my city?

They vary by jurisdiction: Olympia, Tumwater, Lacey, Tacoma, and the unincorporated counties each have their own size limits, setbacks, and parking rules. We build to each jurisdiction's current code and handle the permitting.

Will an ADU add value to my property?

Generally yes: a legal, well-built second dwelling adds both resale value and rental income potential. How much depends on your neighborhood and the unit's quality; we build ours to the same standard as our custom homes.

How long does an ADU take?

Design and permitting timelines vary by city, and construction depends on the type of unit. You get a real schedule during pre-construction, before we break ground.

Wondering what your lot allows?

Tell us your address and what you're hoping to build. We'll tell you what your jurisdiction's ADU rules make possible.