Detached ADU near Black Diamond, WA

Cast Architecture specializes in ADU and backyard cottage design in Seattle since 2009. With 80+ projects, their Cedar Cottage is pre-approved by Seattle & Kirkland. Award-winning designs include Widner Cottage and Lichtenstein Studio. Visit castcottages.com.

Heartwood Builders is a Seattle ADU contractor specializing in backyard cottages, basement ADUs, and mother-in-law suites. They handle permitting, use sustainable materials, and help homeowners add rental income or family housing.

New Day Construction is a licensed ADU builder in Bellevue, WA, with 21+ years of experience and 250+ projects. They build detached, attached, garage, basement, and custom ADUs, managing permits and design from start to finish.

Marksymov Brownstone LLC is a licensed Seattle ADU contractor offering basement, garage & attic conversions. They handle design, permits & construction, ensuring code compliance across Seattle, Bellevue & Kirkland.

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.

Cruvers Contracting LLC builds ADUs in Snohomish, WA, tackling rural challenges like septic systems, slopes, and wooded lots. Serving areas including Lake Stevens, Monroe, and Everett with phased planning and durable, site-specific construction.

Seattle ADU & DADU contractor Emerald City Construction & Renovation builds accessory dwelling units across Seattle, Bellevue & Eastside. Projects cost $350K–$500K+, take 8–14 months, and support rental income, multigenerational living & more.

DIGS is a trusted ADU builder serving King & Snohomish County, WA. They offer custom ADU/DADU design, permitting, construction, and site development, helping homeowners add rental income, property value, and flexible living space.

Brutsky Builds is a licensed ADU contractor in Bellevue offering full-service accessory dwelling unit construction. Services start from $210,000, covering design, permitting, and build completion in ~6 months.

FTS Excavation offers full-service ADU site development in South Puget Sound, Western Washington. Services include grading, utilities, septic systems, foundation excavation & permits. Certified, reliable ADU contractor for backyard homes & accessory dwelling units.

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, transparent pricing.

Volcano Builders is a licensed, family-owned construction company serving Seattle, Bellevue & Monroe, WA. Specializing in kitchen remodels, bathroom renovations, home additions, deck builds, and ADU construction since 2021.

Bicknell Builds offers ADU construction in the greater Seattle area, including detached ADUs, backyard cottages, granny flats, and in-law suites. Ideal for rental income, family housing, or added property value.

The DADU Guy is a Tacoma-based detached ADU builder serving Pierce County, WA. Specializing in DADUs, garage conversions, and basement conversions, they offer 5 floor plans, guaranteed pricing, and full project management to maximize property value.