Basement Conversion near Seattle, WA

Cascadia ADU builds attached, detached, garage & basement ADUs across King, Snohomish, Skagit & Chelan Counties, WA. Full-service design, permitting & construction completed in 8–10 weeks with 10+ years experience.

Northwest ADU is a full-service ADU contractor in Western Washington specializing in detached ADUs, garage conversions, and basement conversions. Serving Pierce, King, and Snohomish Counties, projects range from $180K–$350K+, taking 6–10 months.

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.

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.

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.

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.

Harjo Construction builds AADUs & DADUs in Seattle with 300+ projects since 2010. Costs range $275K–$650K, max 1,000 sq ft, 4–6 month build time. Seattle removed owner-occupancy rules, boosting ADU rental potential.

Better Builders is a Seattle-based general contractor specializing in residential remodeling, garage conversions, ADUs, kitchen and bathroom remodels, basement finishing, deck repairs, and exterior work, with dedicated project management.

Levite Construction Co is a Seattle-based family-owned general contractor offering kitchen remodeling, bathroom remodeling, ADU construction, garage conversions, new builds, interior design, and more across the Greater Seattle area.

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.

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.

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.

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.

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.