Prefab / Modular ADU

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.

Humbuildt Homes is an Arcata, CA general contractor specializing in sustainable prefabricated homes for Humboldt County. They offer affordable, energy-efficient housing guided by integrity, innovation, and quality, with a streamlined build process from consultation to completion.

Small House Solutions is Houston's premier ADU and tiny home builder, offering custom homes, granny flats, backyard cottages, and tiny home communities. Services include permitting, design, construction, and full turnkey development across Houston and surrounding areas.

Irontown Modular builds prefab ADUs in Southern California starting at $155,000. They manage planning, permitting, factory fabrication & installation. Park Model ADUs start at $145,000. Free site review available.

PANDEN Construction builds custom ADUs in Utah, including detached units, granny flats, and Casitas. Serving Utah, Salt Lake, Davis & Weber Counties, they offer a 1BD/1BA 14x28 model with financing options available.

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.

Pro-built Homes builds factory-constructed Accessory Dwelling Units (ADUs) delivered 99% complete. Ideal as in-law suites, rental units, or backyard cottages, their ADUs offer quality, speed, and long-term value with minimal on-site disruption.

The Smartest Modular ADU for your Backyard

McCain Homes offers prefab ADUs built with 90%+ recyclable modular wall systems, costing 20% less than traditional builds. Models range from 400 sq ft studios to larger series. Acquired by SwiftWall Solutions in 2020.

Skyline Homes offers prefab Accessory Dwelling Units (ADUs) for guest suites, rentals, or multigenerational living. Features include Net Zero Ready builds, smart home options, and flexible configurations like detached ADUs, Casitas, and JADUs.

Bay Builders & Remodeling specializes in custom ADU construction across Santa Clara, San Mateo, and East Bay. Services include attached, detached, garage conversions, and JADUs, helping homeowners add rental income, family housing, or workspace.

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+.

Turnkey ADUs is a Leominster, MA ADU contractor offering modular, prefabricated accessory dwelling units across New England. Models range from $119K–$249,900. Massachusetts' 2024 Affordable Homes Act now allows ADUs up to 900 sq. ft. by right.

Virginia ADUs—backyard cottages, garage conversions, basement apartments—add living space or rental income. Premier Structures builds compliant ADUs statewide, navigating local zoning, permits, and size rules (250–1,200 sq ft).

Paramount Manufactured Sales in Riverside offers Skyline Homes-built ADUs for Southern California homeowners in LA, Orange, Riverside, San Bernardino & San Diego Counties. Models range from 479–849 sq ft. California law now allows detached ADUs up to 1,200 sq ft.