Attached ADU near Mountlake Terrace, WA

Sockeye Homes designs & builds custom ADUs and DADUs, offering full-service support from permits to construction. Fixed-cost packages range from $218K–$335K+, suiting retirees, families & rental income seekers.

Home Care Contractors builds ADUs in King County, including DADUs, garage conversions, and basement units. They handle permits, design, and construction. Costs range from $300K–$700K, with timelines of 7–13 months total.

Emerald ADU Builders Seattle specializes in ADU design, permitting, and construction. They build detached ADUs, attached ADUs, and garage conversions, serving Seattle homeowners with quality craftsmanship and transparent pricing.

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.

Deane Home Services builds ADUs in South King County, WA, including garage conversions, basement remodels, and detached backyard cottages. Licensed, bonded & insured. Serving Kent, Renton, Federal Way & more.

ADUs offer self-contained living with kitchen, bath & bedroom for rental or family use. Room additions expand existing home space. Above & Beyond Construction serves Seattle & Puget Sound homeowners with both project types.

Harjo Construction builds AADUs & DADUs in Seattle with 300+ projects since 2010. Costs range $275K–$650K, max 1,000 sq ft, 4–6 month build time. Seattle removed owner-occupancy rules, boosting ADU rental potential.

Gravity Builders LLC is a licensed ADU contractor and custom home builder in Renton, WA. Specializing in ADU/DADU construction, custom homes, outdoor living spaces, and concrete work, they deliver quality craftsmanship with transparency and integr... read more

Neil Kelly Washington offers ADU design and build services in the Northwest, including detached ADUs, garage conversions, and attached units. Their team navigates local permits, balances design with functionality, and helps homeowners add value th... read more

RT Signature Homes, a Redmond, WA-based ADU contractor and design-build firm, builds detached and attached ADUs, garage conversions, and in-law suites, managing feasibility review, permitting, and construction for functional residential living spa... read more

Red's Construction & Renovation serves Federal Way & South King County, WA, specializing in ADU construction including detached, attached, garage conversions & basement units. Costs range from $50K–$300K+. Licensed, insured, transpar... read more

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.

Love Construction builds ADU & DADU units in Seattle & Puget Sound to Passive House standards. Attached ADUs cost $85K–$280K; DADUs $175K–$550K. Includes permitting, energy modeling & a 5-year warranty.