Attached ADU in Washington
H26 Builders
5207 South Willow Street, Seattle, WA 98118
H26 Builders is a Seattle ADU contractor offering attached ADUs, detached ADUs, and garage conversions. Services include design consultation, permitting support, and project management to help homeowners add functional living or rental space.
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ADA Boomer Construction
806 W 5th Ave., Selah, WA 98942
ADA Boomer references the Americans with Disabilities Act and the aging ‘Boomer’ generation. Our focus on accessibility has stemmed from observing that most homes do not work well for people with mobility issues.
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Coates Design Architects
900 Winslow Way East, Bainbridge Island, WA 98110
Seattle ADUs offer rental income & flexible living. Coates Design Architects guides homeowners through detached, attached, garage & basement conversions. Costs range $200K–$350K+, with 7–11 month timelines. Sustainable design & permit-ready plans included.
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Above & Beyond Construction
13346 Eastbrook Drive Southwest, Port Orchard, WA 98367
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.
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Pelletier Construction Group
1150 North 84th Street, Seattle, WA 98103
BB Builders Pro
801 Southwest 16th Street, Renton, WA 98057
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.
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Haas Development & Construction
4001 Aurora Avenue North, Seattle, WA 98103
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 family housing.
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Armada Design & Build Inc.
15600 Northeast 8th Street, Bellevue, WA 98008
Armada Design & Build Inc., Bellevue, WA, offers full-service residential design-build since 2011. Specializing in remodels, home additions, and custom builds across Puget Sound, they deliver turnkey solutions with in-house design and quality craftsmanship.
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Avead
3600 136th Place Southeast, Bellevue, WA 98006
Avead is an ADU contractor offering full-service accessory dwelling unit construction, including attached, detached, junior ADUs, garage conversions, and custom builds. With 20+ years of experience, transparent pricing, and a 5-year warranty.
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Homecare Heroes
930 1/2 Valley Mall Parkway, Wenatchee, WA 98802
When you choose Your Home Care Heroes, you’re choosing expertise focused on one goal: creating an exceptional building experience. Our clients consistently tell us they ‘love their home and wouldn’t change a thing,’ citing our clear communication, attention to detail, and unwavering support throughout the process.
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Evola Builds LLC
Poulsbo, WA 98370
Evola Builds LLC, led by Michael and Amber Evola, offers residential renovation and construction services including bathroom remodels, ADU work, garage conversions, and structural modifications, collaborating closely with architects and homeowners.
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Northwest Builders & Renovation
1135 Lake Washington Boulevard North, Renton, WA 98057
Bellingham ADU Builders
2111 King Street, Bellingham, WA 98225
Bellingham ADU Builders offers full-service ADU construction in Whatcom County, including detached and attached ADUs. Costs range from $200K–$550K+. Permits included. Free 48-hour feasibility study available. HB 1337 allows up to two ADUs per lot.
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Heartwood Builders
1902 North 34th Street, Seattle, WA 98103
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.
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Puget Sound ADU Builders
2226 Eastlake Ave E, Seattle, WA 98102
At Puget Sound ADU Builders, we create functional and cozy and ADUs (Accessory Dwelling Units) in Washington. Our company was founded by Tanya Mills and built on a passion for providing high-quality, affordable housing solutions that unite families. With rising costs in traditional housing and care, we offer practical alternatives that allow your loved ones to live independently in comfortable spaces—right in your backyard.
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Other cities in Washington
What you need to know
Searching for top Attached ADU ADU Contractors in Washington? Our directory highlights trusted local professionals who specialize in designing and building accessory dwelling units (ADUs).
Working with a qualified Attached ADU ADU Contractor in Washington ensures your ADU project meets local building codes, zoning laws, and permit requirements. Whether you're planning a detached ADU, garage conversion, or backyard cottage, experienced Attached ADU professionals can guide you through every step.
Washington homeowners are increasingly investing in ADUs to create additional living space, generate rental income, or support multigenerational living. The Attached ADU experts featured here bring local expertise and proven experience to help make your project a success.
Browse our listings to find the best Attached ADU ADU Contractors in Washington, and get started today.