Prefab / Modular ADU in California

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.

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.

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.

Sequoia Homes & Backyard Bungalows offer affordable ADU builder services in Carlsbad, CA. From granny flats to in-law suites, they handle design, permits, financing & installation. Projects completed in as little as 8 weeks.

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.

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.

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.

Zume Builders, based in San Mateo, CA, specializes in custom homes, ADUs, and prefab construction across the Peninsula, serving Atherton, Palo Alto, Hillsborough & more.

Nestadu is a full-service ADU builder offering custom site-built and prefab ADUs. Site-built units start at $400/sqft; prefab models from $115K. They handle design, permitting, and construction, plus financing guidance including HELOCs and grants.

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.

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.

North County ADU Construction is a local ADU contractor serving north San Diego County. They specialize in garage conversions, JADUs, detached ADUs, and prefab installs. With 500+ builds and a 96% satisfaction rate, they handle design, permitting, and construction.

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.

Los Angeles Advanced ADU Builders offers full-service ADU construction across LA, including garage conversions, detached units, JADUs & prefab ADUs. With 20+ years experience & 500+ builds, they handle design, permits & zoning compliance.

MTR (Modern Technology Resources Inc.) offers full-service ADU design and construction in Sacramento, CA. Services include custom builds, garage conversions, permit management, and prefab options—helping homeowners add value with functional, affordable accessory dwelling units.