Prefab / Modular ADU in California

CityPaks is a minority & woman-owned ADU builder in the San Francisco Bay Area specializing in affordable, sustainable backyard cottages & detached ADUs using SIP panels. No crane needed, no sales tax, pre-approved in San Jose.

Eco Scale Construction builds ADUs in Sunnyvale, Los Altos & Palo Alto, CA. Services include detached ADUs, garage conversions & JADUs. Costs range from $80K–$400K+. Fully compliant with California ADU regulations.

A1 ADU Contractor specializes in garage conversions and custom ADU construction throughout Los Angeles and the San Fernando Valley. With over 15 years of experience, our team provides complete design, permitting, and construction services to transform underutilized spaces into beautiful, functional living areas. Whether you're creating a rental unit, guest house, home office, or multi-family dwelling, we deliver high-quality craftsmanship and personalized solutions tailored to your needs.

Samara's Backyard ADU offers prefab accessory dwelling units for California homeowners. Five sizes available, including the 950 sq ft XL 10. Factory-built, fire-resistant, energy-efficient, with full-service permitting, installation & flexible financing.

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.

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.

Crest Backyard Homes is San Diego's trusted ADU builder, specializing in prefab, detached ADUs, granny flats & garage conversions. Their all-inclusive team guides homeowners from design to completion, ensuring code-compliant, high-quality accessory dwelling units.

Revival Homes is a California ADU project manager handling planning, financing, design, permitting, and construction. They build detached ADUs, garage conversions, JADUs, and more, with costs ranging from $100K to $300K.

Bastion Structures offers modular concrete masonry homes, ADUs, and tiny houses that are fire-, mold-, and termite-resistant. Models range from 305 SF studios to 3,955 SF homes, ideal for California properties seeking durable, weatherproof living solutions.

SnapADU is San Diego's largest detached ADU design-build company, completing 100+ builds with a 4.9+ rating. They offer in-house design, permitting, and construction with fixed pricing across San Diego County.

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.

Ghousetechnologies is a California ADU contractor offering steel frame accessory dwelling units. Models range from 360–1,200 sq ft. Builds are fire, flood, earthquake, and hurricane-resistant, eco-friendly, and completed faster than traditional construction.

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.

Full Circle Builders offers custom ADU construction in Riverside County & the Inland Empire. Detached ADUs start at $185,000 (590 sq ft, 1BD/1BA). Container homes also available. Turn-key builds, permitting assistance included.