Basement Conversion in Washington

Seattle ADU & DADU contractor Emerald City Construction & Renovation builds accessory dwelling units across Seattle, Bellevue & Eastside. Projects cost $350K–$500K+, take 8–14 months, and support rental income, multigenerational living & 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.

Tiny Cottage Builders NW offers ADU construction, garage conversions, basement finishing & home remodeling in Tri-Cities, WA. Led by Brandon Lott, every project is personally managed ensuring quality craftsmanship & clear communication.

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.

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.

Exceptional Home Builders is a Seattle ADU contractor with 20+ years of experience. They offer full-service ADU construction, design-build, permitting, interior design, and renovations for backyard cottages, garage conversions, and basement units.

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.

Heartwood Builders is a Seattle ADU contractor specializing in backyard cottages, basement ADUs, and mother-in-law suites. They handle permitting, use sustainable materials, and help homeowners add rental income or family housing.

Cascade Master Builders builds ADUs in Wenatchee & East Wenatchee, WA. Services include detached, attached, and garage/basement units. They handle permits, pre-approved plans, and financing guidance via HELOC for North Central Washington homeowners.

Huskies Construction in Renton specializes in home additions, ADUs, and DADUs. Services include garage conversions, granny flats, in-law suites, backyard cottages, and room additions, helping homeowners expand living space or generate rental income.

Rybak & Company LLC builds ADUs in Vancouver, Camas, Washougal & Portland Metro. Services include detached ADUs, garage conversions & in-law suites. Projects start at $175K–$250K+. Free estimates available.

Deane Home Services builds ADUs in South King County, WA, including garage conversions, basement remodels, and detached backyard cottages. Licensed, bonded & insured. Serving Kent, Renton, Federal Way & more.

JDI Construction is a Portland-based ADU contractor offering full design-build services for detached, attached, garage conversion, basement, above-garage, and interior ADUs, including permits and eco-friendly practices.

An ADU (accessory dwelling unit) is a secondary dwelling on a single-family lot. Types include basement apartments, garage conversions & detached cottages. Costs vary by size, design, permits & materials. Professional ADU contractors ensure smooth project execution.

Northwest ADU is a trusted ADU builder in Mill Creek, WA, offering full-service accessory dwelling unit construction, including detached ADUs, garage conversions, and basement conversions, with expert permit and zoning support.