Basement Conversion near Mercer Island, WA

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.

Seattle ADUs offer rental income & flexible living. Coates Design Architects guides homeowners through detached, attached, garage & basement conversions. Costs range $200K–$350K+, with 7–11 month timelines. Sustainable design & permit-ready plans included.

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.

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.

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.

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.

Explore pre-designed ADU floor plans from Modern ADU Plans — studio, 1-bed, 2-bed, garage conversions & more. Save time, reduce costs & maximize property value with ready-to-build accessory dwelling unit designs.

New Day Construction is a licensed ADU builder in Bellevue, WA, with 21+ years of experience and 250+ projects. They build detached, attached, garage, basement, and custom ADUs, managing permits and design from start to finish.

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.

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.

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.

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.

Greater Seattle Remodeling builds code-compliant ADUs across the Seattle metro, including detached ADUs, garage conversions, and basement apartments. They match homeowners with vetted contractors for permits, design, and construction.

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.

Giant Builders Seattle is a Kent, WA general contractor with 20+ years of experience offering ADU construction, garage conversions, kitchen & bathroom remodeling, room additions, roofing, deck building, and more.