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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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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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.
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Tenhulzen Construction offers ADU and DADU construction services in Washington State, providing pre-approved and custom plans. Options suit various budgets and timelines, with benefits including added property value and flexible living spaces.
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Carriage Houses NW is a Pacific Northwest ADU builder specializing in infill housing. They develop ADUs, duplexes, and townhomes, partner with homeowners, and offer fee-to-build services, leveraging WA State HB 1110 and HB 1337 legislation.
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Era Builders is a Seattle-based ADU contractor offering detached ADU construction, design, permitting, remodeling, and commercial renovations. They handle full ADU projects compliant with Seattle zoning rules, using sustainable practices.
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Olympic View Building is an ADU contractor offering detached ADU construction, garage conversions, in-law suites, granny flats, and JADU services. They help homeowners add value and living space while navigating zoning laws and building codes.
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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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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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Abel Construction LLC builds barndominium ADU shells in Black Diamond & Rochester. Ideal for rentals, guest suites & extra living space. Durable, cost-effective & customizable structures for property owners.
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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 Bellevue, WA.
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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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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.
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.