ADU Builder in Seattle, Washington
Verified adu builder businesses in Seattle, WA
Showing 1–16 of 16 listings
Better Builders
As your Seattle home remodeling experts, we create tailored ADU designs—perfect for generating rental income or offering a comfortable space for a loved one.
Blue Lake Construction
Da Vinci Design & Build
DIGS Construction & ADU Builders
DIGS specializes in ADU and DADU construction in Seattle and the surrounding area with custom designs, quality craftsmanship, and local expertise. At DIGS, we believe in the power of possibility and are excited to start this building journey with you.
Fuller Living Construction
Gaspar's Design Build Remodel
Harjo Construction
HSP Garage Conversion
Level Up Construction & Remodeling
Model Remodel
MR Garage Conversion
Puget Sound ADU Builders
At Puget Sound ADU Builders, we create functional and cozy ADUs (Accessory Dwelling Units) in Washington. Our company was founded by Tanya Mills and built on a passion for providing high-quality, affordable housing solutions that unite families.
Renovate Builders
Seattle ADU Builders
Emerald ADU Builders Seattle is your favorite contractor when it comes to the design and building of the ADUs. You may have come across a prefab ADU Seattle going by different names like in-law units, granny flats, sidekick homes, backyard guest houses, and laneway homes among others.
Seattle Backyard Homes
Transform your Seattle backyard into additional living space with expert ADU construction tailored to your home and property. Our specialized builders design and build accessory dwelling units that maximize your land's potential while meeting local regulations and your family's needs.
Seattle-ADU
Frequently Asked Questions — ADU Builders in Seattle
How much does it cost to hire an ADU builder in Seattle?
ADU construction costs in Seattle, Washington vary widely depending on size, type, and site conditions. Detached ADUs typically range from $150,000–$400,000+, while garage conversions and attached ADUs can be more affordable. Contact multiple builders in Seattle to get accurate quotes for your specific project.
How long does it take to build an ADU in Seattle?
In Seattle, the ADU construction timeline typically ranges from 6 to 18 months from permit application to move-in. Permitting alone can take 2–6 months depending on Washington local regulations. Prefab and modular ADUs often have faster timelines than site-built units.
Do I need a permit to build an ADU in Seattle?
Yes, a building permit is required for ADU construction in Seattle, Washington. Your ADU builder will typically handle the permit application as part of their service. Washington has adopted streamlined ADU permitting laws in recent years, which may reduce wait times.
What types of ADUs can be built in Seattle?
Common ADU types in Seattle include detached ADUs (backyard cottages), attached ADUs, garage conversions, basement conversions, and prefab/modular ADUs. The best type for your property depends on lot size, zoning, and budget. A local Seattle ADU builder can advise on what's allowed on your specific parcel.