Prefab / Modular ADU in California

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.

BuildShure specializes in ADUs and tiny homes, offering models like Studio Pod, Casita, and 2-bed Residence built with SIP Panels. They guarantee fixed pricing and pay $500/day for delays, ensuring reliable, energy-efficient backyard cottages.

Dan Boyle Construction offers expert ADU construction in Santa Rosa & Sonoma County. With 30+ years experience, they handle site evaluation, permits, design & full builds for detached ADUs, granny flats & backyard cottages.

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.

Prefab vs. stick-built ADUs explained. Homeplex offers the Clever ADU, an HCD-certified modular unit built all-electric in a factory, saving 5–6 months vs. traditional construction. Costs vary based on site conditions.

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.

Eureka Modular builds steel frame modular ADUs and single family homes. Steel framing offers durability, design flexibility, and sustainability. Ideal for detached ADUs, backyard cottages, granny flats, and casitas with efficient, precise 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.

The Springfield by Superior ADUs is a 2-bed, 2-bath detached ADU with open-concept living, vaulted ceilings, mini-split HVAC, kitchen island, ample storage, and optional ethanol fireplace—ideal as a granny flat or in-law suite.

American Helical (CA LIC #1128975) is a full-service ADU contractor in California offering planning, design, permitting, and construction. A 3rd-generation builder, they provide pre-designed models, custom ADUs, and prefab installs across multiple counties.

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.

Regency Construction & Remodeling BA is a San Francisco ADU contractor offering new builds, space conversions, and prefab ADU solutions. They handle design to completion, manage permits, and ensure compliance with local zoning laws.

Jaws Construction Services builds ADUs, garage conversions, and JADUs. They handle permits, HOA coordination, and offer site-built or prefab options. East Bay ADUs rent for $1,500–$3,500+/month, potentially boosting property value.

Cousin Gary Homes – Sacramento specializes in ADU & JADU construction, offering 80+ floor plans from 546–2,536 sq. ft. Benefits include added property value, rental income & flexible living. California's 2023 ADU laws make building easier than ever.