Prefab / Modular ADU in California

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.

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.

ADU Geeks is a full-service ADU contractor offering planning, design, permitting, and build support. They also provide a $150 online ADU Development Masterclass covering feasibility, financing, and construction, ideal for California homeowners and investors.

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.

Bay Area Home Remodelers builds ADUs in Daly City, San Francisco & San Jose. Services include garage conversions, granny flats, JADUs & detached units. Full project support from permits to completion.

Joy Line Homes offers the ADURA ADU Series — factory-built backyard cottages and granny flats featuring modern design, high-end finishes, and durable materials. An affordable, plan-based ADU solution for homeowners seeking quality detached accessory dwelling units.

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.

California Backyard Homes Inc specializes in prefab ADUs, tiny houses, and modular homes across California. Starting from $44,500, they offer turnkey installation including permits and utility connections, with financing available up to 23 years.

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.

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.

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.

LADU is a full-service ADU builder in Los Angeles managing design, permits, and construction end-to-end. Serving LA, Orange, San Diego & more counties, they offer custom and prefab ADUs with transparent pricing and free on-site evaluations.

Sacramento's Summit Building Group offers full-service ADU construction, including custom design, permitting, garage conversions, and detached units. They serve homeowners seeking rental income, multigenerational living, or guest suites, backed by a lifetime workmanship warranty.

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.

Econstruct Inc is a Los Angeles ADU contractor offering full-service construction of accessory dwelling units. With 40+ pre-approved designs and 3D/AR tools via Ohana Dwellings, costs range from $200K–$450K+.