An ADU (accessory dwelling unit) is a secondary dwelling on a single-family lot. Types include basement apartments, garage conversions & detached cottages. Costs vary by size, design, permits & materials. Professional ADU contractors ensure smooth project execution.
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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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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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Giant Builders Seattle is a Kent, WA general contractor with 20+ years of experience offering ADU construction, garage conversions, kitchen & bathroom remodeling, room additions, roofing, deck building, and more.
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Better Builders is a Seattle-based general contractor specializing in residential remodeling, garage conversions, ADUs, kitchen and bathroom remodels, basement finishing, deck repairs, and exterior work, with dedicated project management.
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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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Avio Homes is a Seattle-based ADU contractor specializing in detached ADUs, backyard cottages, and in-law suites. Serving Seattle, Tacoma, and Olympia, they handle design, permitting, and construction with local zoning expertise.
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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.
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ModernSpace ADU Construction is a certified ADU builder serving Redmond, offering tailored accessory dwelling unit services. Competitive pricing, no hidden fees, and a satisfaction guarantee make them a trusted local choice.
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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.
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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.
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We specialize in building high-quality, custom Accessory Dwelling Units (ADUs) that provide both functionality and style for homeowners in Port Orchard, WA, and the surrounding areas. Whether you’re looking to add a rental property, create a cozy space for family, or simply expand your living area, an ADU is a versatile and valuable investment.
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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.
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Chapman Projects offers ADU design and construction in Seattle, Bellevue, and King County. With 20+ years of experience, they provide custom accessory dwelling units, detached ADUs, and backyard cottages using sustainable building practices.
read moreSeattle, Washington has become one of the most ADU-friendly cities in the United States. In 2019, the city passed landmark legislation that significantly relaxed restrictions on Accessory Dwelling Units (ADUs), allowing homeowners to build both an attached ADU and a detached ADU (DADU) on the same property simultaneously. This progressive policy shift has created a booming demand for experienced ADU contractors in Seattle, making it essential to find professionals who understand the city's unique regulatory landscape.
Hiring a knowledgeable Seattle ADU contractor means working with someone who is well-versed in the city's specific building codes and zoning requirements. Seattle's Department of Construction and Inspections (SDCI) oversees all ADU permits, and navigating this process requires expertise. Some critical regulations include:
Finding the right ADU builder in Seattle is critical to the success of your project. The city's hilly terrain, frequent rainfall, and older housing stock present unique construction challenges. A qualified contractor should have experience working with Seattle's soil conditions, understanding of stormwater management requirements, and familiarity with the city's energy code, which aligns with Washington State's strict energy efficiency standards. Always verify that your contractor holds a valid Washington State contractor's license and carries proper liability insurance.
The permitting process for ADUs in Seattle can be complex and time-consuming. Working with an experienced Seattle ADU contractor who understands the SDCI's online permitting portal and plan review process can save significant time and money. The typical steps include:
With Seattle's consistently high rental demand and competitive housing market, building an ADU is a smart financial investment. Seattle ADU contractors report strong interest from homeowners looking to generate rental income, house family members, or increase overall property value. Whether you're considering a backyard cottage, a garage conversion, or a basement ADU, partnering with a skilled and licensed contractor who knows Seattle's building environment is the key to a successful and compliant project.