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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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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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 valu... read more
Neil Kelly Washington offers ADU design and build services in the Northwest, including detached ADUs, garage conversions, and attached units. Their team navigates local permits, balances design with functionality, and helps homeowners add value th... read more
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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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.
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Love Construction builds ADU & DADU units in Seattle & Puget Sound to Passive House standards. Attached ADUs cost $85K–$280K; DADUs $175K–$550K. Includes permitting, energy modeling & a 5-year warranty.
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Huskies Construction in Renton specializes in home additions, ADUs, and DADUs. Services include garage conversions, granny flats, in-law suites, backyard cottages, and room additions, helping homeowners expand living space or generate rental incom... read more
Gordon T. Jacob is a family-run ADU builder and home remodeling contractor in South Puget Sound. Specializing in detached ADUs, backyard cottages, middle housing, and full home renovations in the Tacoma area.
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Home Care Contractors builds ADUs in King County, including DADUs, garage conversions, and basement units. They handle permits, design, and construction. Costs range from $300K–$700K, with timelines of 7–13 months total.
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An Accessory Dwelling Unit (ADU) is an independent living space on a single-family property. Washington State's HB 1337 boosted ADU construction, easing zoning rules, removing owner-occupancy requirements, and capping impact fees at 50%.
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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.
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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.
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.