Basement Conversion in California

Coastal ADU Construction is a Bay Area design/build contractor specializing in accessory dwelling units. They handle detached ADUs, garage conversions, in-law suites, and granny flats, managing both design and construction while navigating local zoning regulations.

Elite Construction builds ADUs in Santa Cruz County, offering detached units, garage conversions & addition ADUs. Projects range 250–1,200 sq ft, cost $115K–$450K, and take 6–9 months. Free estimates available.

Bartona Builders specializes in ADU construction in Los Angeles, offering detached ADUs, garage conversions, and in-law suites. They manage the full build process, ensuring code-compliant construction that adds value to residential properties.

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.

ADUs are secondary units built on existing lots. ORR Construction builds detached ADUs, garage conversions, JADUs & in-law suites in California. Costs range $50–$300/sq ft. California laws like SB 897 simplify the permitting process.

Build Method Construction is a licensed ADU contractor in Los Angeles County with 25+ years of experience. They build detached ADUs, garage conversions, JADUs, and more—handling design, permits, and construction for single and multi-family properties.

Element Home Remodeling is a Mountain View ADU contractor offering full design-build services in Silicon Valley. They specialize in garage conversions, backyard cottages, in-law suites & rental units, serving Palo Alto, Sunnyvale & San Jose.

Fortune ADU is a Southern California ADU contractor offering full-service design, permitting, and construction. Services start at $3,999.99, covering detached ADUs, JADUs, garage conversions, and more, with most projects completed in 6–12 months.

Y.O.R. Construction & Investments is a licensed Southern California general contractor (Lic. #978430) offering residential & commercial services including remodeling, room additions, pool construction, and ADU/garage conversions.

Humboldt ADU is a Humboldt County program helping homeowners build Accessory Dwelling Units (ADUs) like granny flats or backyard cottages to boost affordable housing. It offers guides on types, permits, financing, and construction.

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.

C.J. Skeeles General Contractor specializes in ADU construction in Hayward, Oakland & San Francisco, CA. Services include detached ADUs, garage conversions & interior conversions, all built to California zoning & permitting requirements.

ADU Los Angeles (ADLA) is a specialized ADU contractor serving LA County. They offer consulting, custom design, construction, garage conversions, basement ADUs, attached and detached units, helping homeowners maximize property value.

ADU 4 You Pros is a California Central Valley ADU contractor offering full-service accessory dwelling unit solutions, including detached ADUs, garage conversions, and in-law suites, handling design, permitting, and construction.

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