Seattle's 2019 ADU law changes made it easier to build accessory dwelling units on single-family lots. DADUs can't exceed 50% of the main home's size. No parking required. New detached ADUs start around $350,000.
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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 & per... read more
Sockeye Homes designs & builds custom ADUs and DADUs, offering full-service support from permits to construction. Fixed-cost packages range from $218K–$335K+, suiting retirees, families & rental income seekers.
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HiLine Homes is an experienced ADU builder in Idaho with nearly 30 years in custom home construction. They offer attached and detached ADU designs for rental income, multigenerational living, or home offices, with financing options available.
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Northwest ADU builds custom detached ADUs, garage conversions & basement ADUs across Western Washington. Serving King, Pierce & Snohomish Counties with full-service ADU construction, build-ready plans & permit management.
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Puget Sound ADU Builders is a leader in ADU construction in western Washington state, excelling in design, construction, finishing, and permitting ADUs, DADUs, backyard cabins, garage conversions, duplexes, town homes, and multi-unit projects.
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New Day Construction is a licensed ADU builder in Bellevue, WA, with 21+ years of experience and 250+ projects. They build detached, attached, garage, basement, and custom ADUs, managing permits and design from start to finish.
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Seattle Tiny Homes, based in Buckley, WA since 2005, builds tiny houses, park models, and modular ADUs under 400 sq ft. Washington state-certified, they offer financing options and helped establish the Washington Tiny House Association.
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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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J Hanby LLC offers ADU and basement conversion services in the Eastside area. Specializing in detached ADUs, garage conversions, granny flats, and basement renovations, they help homeowners maximize property value and ROI.
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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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Volcano Builders is a licensed, family-owned construction company serving Seattle, Bellevue & Monroe, WA. Specializing in kitchen remodels, bathroom renovations, home additions, deck builds, and ADU construction since 2021.
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Hammer & Hand is a Portland & Seattle general contractor with 30+ years of experience in new homes, remodels, ADUs & commercial builds. Employee-owned, they offer expert craftsmanship, custom woodwork & trusted subcontractor networ... read more
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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Federal Way, Washington, is one of the fastest-growing cities in South King County, with a diverse population and a strong demand for affordable housing solutions. As the city continues to expand, Accessory Dwelling Units (ADUs) have become an increasingly popular option for homeowners looking to add rental income, house extended family members, or increase property value. Working with experienced ADU contractors in Federal Way, WA is essential to navigating the city's specific zoning codes, permitting requirements, and construction standards.
Federal Way operates under its own municipal code, separate from King County, which means ADU regulations are governed by the Federal Way Revised Code (FWRC). Homeowners and contractors must be familiar with these local rules before beginning any ADU project. Key regulations include:
Obtaining the proper permits is a critical step in any ADU construction project in Federal Way. The Federal Way Community Development Department oversees building permits, and all ADU projects must comply with Washington State Building Code (WSBC) as well as local amendments. A qualified ADU contractor in Federal Way will handle the full permitting process, including submitting architectural plans, site plans, and engineering documents. Permit timelines can vary, so working with a contractor experienced in Federal Way's specific review process can help avoid costly delays.
Choosing the right contractor for your ADU project in Federal Way is crucial to a successful outcome. Here are some important qualities to look for:
With Federal Way's growing rental market and rising property values, building an ADU is a smart long-term investment. Whether you're considering a garage conversion, basement ADU, or a brand-new detached unit, partnering with a knowledgeable ADU contractor in Federal Way, Washington ensures your project meets all local requirements and is completed to the highest standard. Start your ADU journey today and take advantage of one of South King County's most promising housing opportunities.