Basement Conversion in California

ADU Builders Bay Area specializes in detached ADUs, garage conversions, in-law suites & more. Expert ADU contractors offering transparent pricing, full permitting & quality construction throughout the Bay Area.

Building a granny flat (ADU) in San Diego can boost property value and ease housing needs. Detached ADUs up to 1,200 sq ft start at $250/sq ft. Fee waivers may save homeowners $14,000+. Rules apply regarding zoning, lot use, and size limits.

MyADU4Less is a Southern California ADU builder specializing in prefabricated accessory dwelling units. Offering models from 160–1,200 sq ft, they handle design, permitting, and construction. CalHFA grants up to $40,000 may apply.

Home 360 Construction Inc. offers full-service ADU construction in San Diego, including detached, attached, and garage conversion units. They manage planning, permits, design, and inspections across San Diego County neighborhoods.

American Builders is a San Francisco ADU contractor specializing in garage conversions, detached units, in-law suites & basement conversions. They handle permits, zoning, and deliver code-compliant accessory dwelling units on time and on budget.

Central Coast ADU offers full ADU planning, design, and permitting services for homeowners on the Central Coast. From granny flats to garage conversions, they deliver construction-ready plans and approved permits.

ADUscale is an independent ADU advisory service offering feasibility assessments, contractor verification, escrow-based payment protection, and construction oversight. Fixed-fee, conflict-free guidance for homeowners planning detached ADUs, garage conversions, or backyard cottages.

ORO Coast Builders is an ADU contractor in Los Angeles & the Bay Area with 25+ years of experience. They build detached ADUs, garage conversions, basement conversions & JADUs—fully custom, no prefab.

Golden ADU, serving Southern California since 2021, specializes in custom ADU construction including garage conversions and detached backyard cottages. They offer flexible financing with no upfront costs, completing most projects in 6–12 months.

Bay Area design-build ADU specialists. One project, one point of contact — design, engineering, permitting, and construction from start to finish. CSLB #1130783.

Backyard Homes is a top ADU builder in Sacramento with 80+ completed units. They offer detached, attached, and conversion ADUs, handling design, permitting, and construction for a seamless experience across the greater Sacramento region.

Urbatect Development LLC is a California & Washington ADU contractor offering custom homes, garage conversions, JADUs & detached ADUs. 15+ years experience, 3,500+ projects, fixed pricing, fast permitting & 3D design.

Aldridge Construction builds ADUs in Salinas, CA—detached, attached, garage conversions & interior units. Projects cost $150K–$300K, take 4–8 months, and include full permitting support. Free consultations available.

Premium ADU is a Los Angeles ADU specialist offering design, permitting, and construction of detached ADUs, garage conversions, and JADUs. Operating since 2021 with an in-house team, projects typically complete in 6–12 months.

ExpandADU is a California-based prefab ADU builder offering full-service accessory dwelling unit construction, including consultation, design, planning, and build. Serving the Bay Area and beyond, they specialize in detached ADUs, granny flats, and JADUs.