Prefab / Modular ADU

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+.

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.

EHD Builders offers ADU construction services in Los Angeles, CA, including garage conversions, detached units & additions. Costs range from $150K–$350K+. Services cover permits, framing, plumbing, electrical & more.

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.

Caserella Tiny builds custom ADUs using durable steel framing. Models start at $65,000 (200 sq ft) to $99,000 (400 sq ft). Benefits include termite resistance, fire safety, mold resistance, and high thermal efficiency—ideal for rental, family, or workspace use.

Genesis Homes is a leading ADU builder in the US, specializing in factory-built accessory dwelling units for developers. Available in 48 states, their offsite construction model offers speed, cost savings, and quality for granny flats, in-law suites, and backyard cottages.

Maui Eco Built offers prefab & custom ADUs, granny flats, and homes on Maui. Panelized construction cuts build time. Structures range from permit-exempt under 200 sq ft to 3,000 sq ft homes. Design, permits & site planning available.

LiveLarge Home is a California prefab ADU builder offering full-service solutions from permits to final inspection. Build times start at 4–6 weeks, with fixed pricing from $412/sq. ft. Models range from studios to 2-bed/2-bath units with premium finishes.

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 & granny flats.

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.

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 counties.

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.

Sioux Falls Home Remodeling builds custom ADUs in Sioux Falls, SD. Services include detached ADUs, garage conversions, granny flats & in-law suites. Costs range from $25K–$180K+. Serving Minnehaha & Lincoln Counties.

Alpine Forge builds precision ADUs and tiny homes in Nampa, Idaho. Using a panelized method, they offer faster timelines, cost predictability, and energy-efficient designs for rental units, guest houses, in-law suites, and backyard cottages.

TinyMod (TMOD™) is an offsite development partner offering feasibility analysis, project management, and factory coordination for builders. Services support ADUs, modular communities, BFR, and missing middle housing with up to 60% faster build times.