Attached ADU in Washington

Twin Brothers Group is a licensed framing contractor in Washington State specializing in ADU, DADU, garage conversions, and home additions across King and Snohomish County, serving Seattle-area GCs and owner-builders.

Lakeside ADU & Home Planning, based in Lake Stevens, WA, is a full-service ADU builder serving the Puget Sound Region. They specialize in backyard cottages, mother-in-law suites, garage conversions, and new builds, managing design, permitting, and construction.

Drew Thatcher Construction builds ADUs in Lakewood, WA, including detached units, attached ADUs, and garage conversions. Founded by a Navy nuclear engineer, they offer design-build services with local Pierce County expertise.

Greenpod Design builds custom DADUs in Washington using SIP construction and sustainable materials. They handle permits, ADA-compliant design, and energy-efficient builds. WA law allows up to two ADUs per lot, up to 1,000 sq ft.

NorthLight Custom Builders offers ADU construction in King & Snohomish County. Services include attached & detached units for rental income, family living, or home offices. Structured process from consultation to one-year warranty follow-up.

Zee Design & Build is a Kirkland, WA ADU contractor serving King, Snohomish, Skagit & Island Counties. Offering full-service ADU construction—garage conversions, basement units, backyard cottages & more—since 2012.

Greater Seattle Remodeling builds code-compliant ADUs across the Seattle metro, including detached ADUs, garage conversions, and basement apartments. They match homeowners with vetted contractors for permits, design, and construction.

Adair Homes offers custom ADU builder solutions, including stand-alone and attached accessory dwelling units. With a six-step building process, financing via Basis Home Loans, and expert guidance, Adair simplifies new home and ADU construction.

An Accessory Dwelling Unit (ADU) is an independent living space on a single-family property. Washington State's HB 1337 boosted ADU construction, easing zoning rules, removing owner-occupancy requirements, and capping impact fees at 50%.

JDI Construction is a Portland-based ADU contractor offering full design-build services for detached, attached, garage conversion, basement, above-garage, and interior ADUs, including permits and eco-friendly practices.

NW Build specializes in ADU & DADU construction in Bellevue and the Puget Sound region. They manage permits, design, and builds for detached ADUs, attached units, and granny flats, adding value to residential properties.

Alta Casa Remodeling is a Vancouver, WA ADU builder specializing in accessory dwelling units, garage conversions, in-law suites, and home additions. They also offer kitchen, bathroom, and full home remodels, backed by a one-year workmanship warranty.

Backyard ADU is a full-service ADU contractor managing every stage of accessory dwelling unit builds, including feasibility, permits, site surveys, foundations, construction, utility connections, and condo legal services.