Twin Brothers Group is a licensed framing contractor in Washington State specializing in ADU, DADU, garage conversions, and home additions across King and Snohomish County, serving Seattle-area GCs and owner-builders.
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Brutsky Builds is a licensed ADU contractor in Bellevue offering full-service accessory dwelling unit construction. Services start from $210,000, covering design, permitting, and build completion in ~6 months.
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Cruvers Contracting LLC builds ADUs in Snohomish, WA, tackling rural challenges like septic systems, slopes, and wooded lots. Serving areas including Lake Stevens, Monroe, and Everett with phased planning and durable, site-specific construction.read more
Microhouse is a Seattle-based ADU builder specializing in custom detached ADUs (DADUs). They guide homeowners through zoning, design, and construction. Seattle permitted 551 DADUs in 2022, with a 40% increase in 2023. Microhouse offers site assess... read more
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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RT Signature Homes, a Redmond, WA-based ADU contractor and design-build firm, builds detached and attached ADUs, garage conversions, and in-law suites, managing feasibility review, permitting, and construction for functional residential living spa... read more
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.
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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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FTS Excavation offers full-service ADU site development in South Puget Sound, Western Washington. Services include grading, utilities, septic systems, foundation excavation & permits. Certified, reliable ADU contractor for backyard homes &... read more
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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Cast Architecture specializes in ADU and backyard cottage design in Seattle since 2009. With 80+ projects, their Cedar Cottage is pre-approved by Seattle & Kirkland. Award-winning designs include Widner Cottage and Lichtenstein Studio. Visit c... read more
Raincap Construction, a Seattle-based family-owned contractor, specializes in ADU and DADU construction. They build backyard cottages, in-law suites, and garage conversions, helping homeowners add living space, rental income, and property value.read more
Gravity Builders LLC is a licensed ADU contractor and custom home builder in Renton, WA. Specializing in ADU/DADU construction, custom homes, outdoor living spaces, and concrete work, they deliver quality craftsmanship with transparency and integr... read more
SeaTac, Washington is a unique city shaped largely by its proximity to Seattle-Tacoma International Airport. This means that ADU contractors working in SeaTac must navigate not only standard King County and city zoning regulations, but also Federal Aviation Administration (FAA) height restrictions and noise compatibility guidelines. These aviation-related constraints can directly impact the design and construction of Accessory Dwelling Units, making it essential to hire an experienced ADU contractor who understands the local landscape.
SeaTac operates under its own municipal code, separate from unincorporated King County. Homeowners looking to build an ADU in SeaTac must comply with the SeaTac Municipal Code Title 15, which governs land use and zoning. Key considerations include:
One of the most distinctive challenges for ADU contractors in SeaTac is addressing aircraft noise. The city falls within the Airport Influence Area, and many properties are subject to significant noise levels measured in Day-Night Average Sound Levels (DNL). Contractors must often incorporate sound attenuation measures such as enhanced insulation, double-pane or triple-pane windows, and specialized ventilation systems to meet habitability standards. Some properties may even qualify for the Port of Seattle's Residential Sound Insulation Program, which can offset certain construction costs.
Working with an ADU contractor who has direct experience in SeaTac provides significant advantages. A knowledgeable local contractor will be familiar with:
Despite its unique regulatory environment, SeaTac presents a strong opportunity for ADU development. The city's location along the Link Light Rail corridor and its proximity to major employment hubs make rental ADUs highly attractive. With Washington State's ADU-friendly legislation continuing to evolve, now is an excellent time to consult with a qualified SeaTac ADU contractor to explore your options, maximize your property's potential, and ensure full compliance with all local, state, and federal requirements.