Prefab / Modular ADU

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... read more

Pathway Builders offers custom and semi-custom ADU construction in Boise and Treasure Valley. They build detached, attached, and garage conversion ADUs. Use their online instant quote tool to estimate costs before consulting.

Gauntlet Construction is a licensed ADU builder & design-build contractor in Roseville, CA. Serving Sacramento & Placer County, they offer ADU construction, garage conversions, home renovation & commercial builds with 15+ years of expe... read more

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... read more

Tiny Mountain Houses, based in Silverton, Oregon, builds custom tiny house RVs certified to ANSI/NFPA 1192/1195 codes. Offering diverse floor plans and sizes, the BBB-accredited company serves full-time living, travel, or backyard cottage needs ac... read more

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.

BSPK Design is a Venice, CA residential studio founded by Chris Faulhammer & Roman Reiterer, with 50+ years combined experience. Services include custom homes, fire rebuilds & prefab NextGen Building. Multiple Houzz Best of Design award wi... read more

Studio Home is a Colorado-based prefab ADU builder serving all 50 states. With 18+ years experience and 6,000+ projects, they offer panelized ADU kits, backyard studios, granny flats, and in-law suites with fixed pricing and full project managemen... read more

Park Atlanta Construction builds custom homes, ADUs, remodels & more across Atlanta. With 30+ years experience, they handle design, permitting & construction. Standard ADU plans from 352–750 sq ft available. Serving south metro Atlanta t... read more

Specialist ADU builder constructing durable, eco-friendly homes from repurposed shipping containers. Hurricane, earthquake & tornado resistant, IBC-compliant. Models range from 208–1760 sq ft. Custom designs available for backyard cottages &... read more

Harmony Design & Build specializes in ADU construction in San Diego, CA. Services include detached ADUs, garage conversions, attached units & custom designs. Ideal for rental income, in-law suites & added property value.

BuildLabs is a design-build company specializing in ADU construction across all 50 states. They offer custom and pre-approved plans, sustainable materials, and a streamlined 16-week build process covering planning, permitting, and final inspection... read more

Lifescape Builders Inc provides ADU construction services in Temecula and Riverside County, including detached ADUs, granny flats, in-law suites, casitas, garage conversions, and JADUs, with customizable layouts, finishes, and full custom build op... read more

Victory Home Remodeling builds detached, attached, garage conversion, Junior, and above-garage ADUs in Los Angeles. Benefits include added property value, rental income, and multi-generational living. Timelines range from 2–10 months depending o... read more