US Modular, Inc., ADU Builders
Southern California’s Premier Contractor for Manufactured Homes
US Modular, Inc. is a licensed, bonded, and insured manufactured home and ADU builder with over 60 years of combined experience. A true one-stop shop, US Modular is a full-service prefab housing company handling:
- Design
- Permitting
- Installation
- Utilities
- And more!
Call to speak with a licensed project consultant today and schedule an on-site evaluation.
What We Build
Accessory Dwelling Units (ADUs)
US Modular is an ADU specialist, building units that can serve multiple purposes. Whether you need a home for an aging parent, adult children, or for some nice rental income, we are your full-service ADU builder in California.
Manufactured Single-Family Homes
US Modular offers high-quality manufactured single-family homes that provide all the amenities and finishes you expect from a new house. Manufactured homes are built with the same materials as site-built homes, with faster build times and lower costs. Our homes are constructed to the federal HUD code.
MH Advantage® Homes
MH Advantage-eligible manufactured homes are built to the HUD code and combine factory-built efficiency with site-built curb appeal. Low-profile foundations, higher roof pitches, porches, and garages help your home blend seamlessly into established neighborhoods; some buyers may also explore specialized financing through participating lenders (eligibility varies).
Multi-Family Homes
At US Modular, we also offer multi-family duplexes built under manufactured housing standards—the same high quality as our single-family homes—with multiple sign-offs and third-party/state inspections.
Why US Modular
- US Modular is your contractor for end-to-end manufactured home building services.
- With over 60 years of combined experience, we have the know-how to help you design the perfect home for your specific needs.
- Prefabricated homes are built with the same materials as site-built structures, but often with better energy efficiency.
- US Modular offers homes with competitive, transparent starting prices.
- As a premier Southern California prefab home and ADU builder, we have strong knowledge of permitting and construction requirements across SoCal, including San Diego, Riverside, San Bernardino, Orange, and Los Angeles counties.
How It Works
- Your manufactured home or ADU construction journey is completed in four steps:
- Speak with a licensed project consultant and see if a manufactured or ADU home is a good fit for your needs.
- Schedule an on-site evaluation to assess your property.
- Your prefab ADU or manufactured home is designed according to your preferences. Our team acquires permits for construction.
- Your new home is fabricated and installed, typically within 3 months after permits are finalized.
Complete step one today!
Service Areas
US Modular is the manufactured home and ADU builder of choice in Southern California. We’re proud to serve the counties of Riverside, San Bernardino, Orange, Los Angeles, and San Diego.
Connect with our team to ask about prefab homes and ADUs in your area!
Download our free Cottage Series ADU Brochure
Ready to Build?
Get one responsible team for every step of the process with US Modular’s ADU builders and manufactured home experts.
FAQs
How long does a project take?
Most projects run about 6–9 months end-to-end. After permits are approved, the factory build, delivery, and installation typically complete in ~3 months. Timelines vary by city and site conditions, and an on-site evaluation helps set accurate expectations.
Do you handle permits, utilities, and installation?
Yes. We’re a true one-stop shop. From design, permits, site work, utilities, and installation, all the way to the certificate of occupancy, you have a single responsible party from start to finish.
Manufactured vs modular—what’s the difference?
Manufactured homes are factory-built to the federal HUD code (typically single-story) and set on permanent foundations.
Modular homes are factory-built to state/local codes and can be multi-story.
We began as modular home builders years ago, but today we focus on manufactured ADUs, single-family homes, and small duplexes in Southern California, as the quality of manufactured homes typically meets or even exceeds the quality of site-built and modular homes. Manufactured homes are often more affordable and faster to build than modular homes, too!
Do you have prefab homes for sale?
We’re a builder, not a retail lot. Each project is designed and permitted for your property. To explore options and request current starting ranges, browse our floor plans & pricing via our interactive tools.
Where do you build?
We serve Southern California, primarily Riverside, San Bernardino, and San Diego counties, with select projects in Los Angeles and Orange counties. If you’re searching for ADU builders near me, start with a call to confirm feasibility for your address.
What is an ADU and who is it for?
An Accessory Dwelling Unit (ADU) is a secondary home on a residential lot, often used for aging parents, adult children, or rental income. As a prefab ADU/factory-built homes specialist, we help you choose a plan that fits your lot, goals, and local requirements.