ADU Contractors near Federal Way, WA
FTS Excavation
12714 151st Street East, Puyallup, WA 98374
13.6 miles
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 & accessory dwelling units.
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The DADU Guy
2522 North Proctor Street, Tacoma, WA 98406
7.7 miles
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 value.
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ModernSpace ADU Construction Redmond
17181 Redmond Way, Redmond, WA 98052
27.1 miles
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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Bicknell Builds
19616 Southeast 310th Place, Kent, WA 98042
12 miles
Bicknell Builds offers ADU construction in the greater Seattle area, including detached ADUs, backyard cottages, granny flats, and in-law suites. Ideal for rental income, family housing, or added property value.
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Marksymov Brownstone
12814 Northeast 139th Street, Kirkland, WA 98034
29.8 miles
Marksymov Brownstone LLC is a licensed Seattle ADU contractor offering basement, garage & attic conversions. They handle design, permits & construction, ensuring code compliance across Seattle, Bellevue & Kirkland.
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H26 Builders
5207 South Willow Street, Seattle, WA 98118
16.3 miles
H26 Builders is a Seattle ADU contractor offering attached ADUs, detached ADUs, and garage conversions. Services include design consultation, permitting support, and project management to help homeowners add functional living or rental space.
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Ballard Backyard Cottages
4142 2nd Avenue Northwest, Seattle, WA 98107
24.1 miles
Seattle's trusted DADU & ADU builder offers custom builds, ADU conversions, and prefab cabins. Transparent pricing, expert guidance, and hands-on construction help homeowners add lasting value with backyard cottages and granny flats.
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Neil Kelly Washington
804 North Alberta Street, Seattle, WA 97217
24.2 miles
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 through custom accessory dwelling units.
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Cast Architecture
115 North 36th Street, Seattle, WA 98103
23.8 miles
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 castcottages.com.
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Model Remodel
1111 West Nickerson Street, Seattle, WA 98119
23.9 miles
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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Tacoma DADU
7809 Pacific Avenue, Tacoma, WA 98408
6.4 miles
Tacoma DADU Builders is a premier detached ADU builder serving Tacoma and Puget Sound. With 40+ years of experience, they offer turnkey ADU construction—design, permitting, and build—for investors, homeowners, and first-time buyers.
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Era Builders
911 Northeast 70th Street, Seattle, WA 98115
25.6 miles
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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Homez Remodel
13213 Southeast 278th Street, Kent, WA 98042
8.6 miles
Homez Remodel is a Seattle ADU builder specializing in DADUs, backyard cottages, garage conversions & basement ADUs. With 10+ years experience, they handle permits, design & construction across Seattle, Bellevue, Kirkland & more.
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Gravity Builders LLC
17422 108th Avenue Southeast, Renton, WA 98055
11.5 miles
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 integrity.
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New Image Construction Management
8305 Dallas Avenue South, Seattle, WA 98108
15.2 miles
New Image Construction Management is a Washington State general contractor and building company based in Seattle, WA. With a primary focus of new home construction and renovation of residential and commercial properties.
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Other cities in Washington
What you need to know
ADU Contractors in Federal Way, WA: Building in a Growing South King County City
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 ADU Regulations and Zoning Requirements
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:
- ADUs are permitted in single-family residential zones, including RS 5.0, RS 7.2, RS 9.6, and RS 35.0 zones.
- Both attached ADUs and detached ADUs (DADUs) are allowed, subject to lot size and setback requirements.
- The maximum size for a detached ADU is typically 1,200 square feet or 50% of the primary dwelling's square footage, whichever is less.
- Owner-occupancy requirements may apply, meaning the property owner must reside in either the primary home or the ADU.
- Setbacks, lot coverage limits, and height restrictions must all be carefully reviewed before design begins.
The Permitting Process for ADUs in Federal Way
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.
What to Look for in Federal Way ADU Contractors
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:
- Local experience: Contractors familiar with Federal Way's zoning codes and permitting process will save you time and money.
- Licensing and insurance: Always verify that your contractor holds a valid Washington State contractor's license and carries liability insurance.
- Design-build capabilities: Contractors who offer both design and construction services can streamline the entire ADU process.
- Transparent pricing: Look for detailed, itemized estimates to avoid unexpected costs during construction.
Invest in an ADU in Federal Way Today
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.