Prefab / Modular ADU in California

US Modular Inc. is a trusted ADU builder in Riverside County, CA, with 35+ years of experience. They offer prefab ADUs, garage conversions & casitas starting at $150,000, completed in 6–9 months.

Cali ADU is a top Los Angeles ADU builder offering custom and pre-designed accessory dwelling units, garage conversions, and granny flats. Fixed pricing, fast permitting, and expert project management ensure stress-free builds from design to move-in.

Addition Builders LA is a full-service ADU contractor in Los Angeles offering custom ADUs, prefab units, and garage conversions. Licensed, bonded, and insured, they manage design to construction, completing projects in as little as nine months with transparent pricing.

ADU Design Homes is a full-service ADU design and build firm in Los Angeles and Orange County. They handle detached ADUs, JADUs, garage conversions, permitting, engineering, and construction under one roof.

LiveLarge Home is a California prefab ADU builder offering full-service solutions from permits to final inspection. Build times start at 4–6 weeks, with fixed pricing from $412/sq. ft. Models range from studios to 2-bed/2-bath units with premium finishes.

ADU Company San Diego County specializes in off-site ADU construction, offering efficient, affordable accessory dwelling units. From granny flats to detached ADUs, their expert team guides clients from concept to Certificate of Occupancy.

Framework First is a family-owned ADU builder in Monterey County, CA, with 40+ years of experience. They offer modular ADUs from 450–1,200 sq ft, handling permits, delivery, and installation with transparent pricing.

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.

Nestadu is a full-service ADU builder offering custom site-built and prefab accessory dwelling units. Prefab models range from $115K–$317K. Custom builds start at $400/sq ft. Financing options include HELOCs, construction loans, and CA grants.

Type Five is a Berkeley, CA-based ADU builder offering custom backyard cottages, granny flats & in-law suites. They combine modular design, transparent pricing & streamlined construction for stress-free, high-quality detached ADUs built to last.

Eagle ADU is a licensed ADU builder in Northern California offering three signature models: Eagle Studio ($180K–$220K), Eagle One ($230K–$280K), and Eagle Two ($310K–$360K), with rental income potential up to $4,000/month.

West Coast ADU is a California-based ADU builder offering prefab & manufactured accessory dwelling units. They help homeowners add rental income, house family members & boost property value with streamlined permitting & construction.

Homestead ADU offers turnkey accessory dwelling units for California homeowners. Models range from 451 to 1,200 sq ft. Offsite modular construction cuts costs by 30% and delivers units in 6–7 months. Serving Shasta & San Luis Obispo County.

prefabADU is a Bay Area ADU builder with 16+ years of experience offering affordable kits and plans from under $45K. With 12 state-approved plans valid across California, they simplify permits, design, and installation for homeowners.

California Tiny House, based in Fresno, CA, builds custom tiny homes, ADUs, granny flats & commercial structures. Offering in-stock models, DIY programs & financing via 21st Mortgage for residential & commercial clients.