Ballard Backyard Cottages
Seattle, WA
4.4(7)
ADU ConstructionBackyard CottageDesign-Build ADU
Specializing in ADU construction and related services in Seattle, WA.
Looking for the best ADU design-build firms in Seattle, Washington? Our directory features 1 vetted adu design-build firms serving the Seattle area. Whether you're planning a new ADU construction, garage conversion, or backyard cottage, find the right builder for your project.
Specializing in ADU construction and related services in Seattle, WA.
Seattle is one of the top markets for accessory dwelling units in Washington. With growing demand for affordable housing, ADU construction in Seattle offers homeowners an excellent opportunity to add living space, generate rental income, or house family members. Our curated list of adu design-build firms in Seattle helps you find experienced professionals who understand local building codes, zoning regulations, and permit requirements.
ADU construction costs in Seattle typically range from $150,000 to $350,000 depending on size, design, and finishes. Garage conversions are generally less expensive ($80,000–$150,000), while custom-built detached ADUs can cost more. Get free quotes from our listed adu design-build firms to compare prices.
Yes, ADU construction in Seattle requires building permits. Washington has specific ADU regulations, and local zoning laws may have additional requirements. Our listed builders can help you navigate the permitting process.
ADU construction timelines in Seattle typically range from 4–12 months, depending on the project type. Prefab ADUs can be installed in 2–4 months, while custom builds may take 8–12 months including design and permitting.