Detached ADU near Mountlake Terrace, WA

True Built Home builds custom ADUs in Washington & Oregon, offering 14 floor plans from 495–1,199 sq ft, priced from $119,900. Plans include granny flats, in-law suites & backyard cottages with transparent pricing and customizable design... read more

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.

NW Finishing is a Seattle-area ADU contractor offering full-service accessory dwelling unit design and construction. Serving Bellevue, Kirkland, Redmond, Renton, and more, they handle permits, planning, and builds for detached, cottage, and prefab... read more

Lindal Homes offers custom ADU and DADU kit home solutions across the US and Canada. Flexible floor plans, the Lindal Elements collection, and system-built construction make adding a backyard cottage or guest suite efficient and cost-effective.read more

Seattle Remodeling LLC specializes in ADU construction in Seattle, offering mother-in-law suites, backyard cottages, garage conversions, and granny flats. They help homeowners add value, rental income, and flexible living space.

Haas Development & Construction offers ADU & DADU construction in Greater Seattle. They handle planning, permits, design, and builds for attached & detached units, including prefab DADU plans, helping homeowners add rental income or fa... read more

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-u... read more

Interbay Construction is a Washington State ADU contractor building guest houses, in-law suites, detached ADUs & backyard cottages. Quality materials, clear communication & reliable timelines for every accessory dwelling unit project.

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.

Northwest ADU is a trusted ADU builder in Mill Creek, WA, offering full-service accessory dwelling unit construction, including detached ADUs, garage conversions, and basement conversions, with expert permit and zoning support.

LYD Construction is a Seattle-area ADU builder & remodeling contractor with 25 years of experience. Services include kitchen, bathroom, basement renovations, deck building & ADU construction. Financing up to $200,000 available. Based in Be... read more

BB Builders Pro specializes in ADU construction, garage conversions, home additions, and detached backyard cottages. Services include custom design, permitting, zoning compliance, and renovations—ideal for rental income or family housing.

Cascadia ADU builds attached, detached, garage & basement ADUs across King, Snohomish, Skagit & Chelan Counties, WA. Full-service design, permitting & construction completed in 8–10 weeks with 10+ years experience.

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.

Explore pre-designed ADU floor plans from Modern ADU Plans — studio, 1-bed, 2-bed, garage conversions & more. Save time, reduce costs & maximize property value with ready-to-build accessory dwelling unit designs.