With over 20 years of experience, Built ADU is Southern California’s trusted installation team for Pre-Fab structures both manufactured and modular covering Multi-Family, Single-Family Residences and Accessory Dwelling Units.
As a licensed B & C-47 contractor, we’re the go-to partner for contractors, dealers, and homeowners who rely on us to manage the entire process—from permitting to final installation—start to finish.
At BuiltADU, we install manufactured and modular homes for developers and homeowners alike — from full single-family residences to Accessory Dwelling Units (ADUs). Whether you’re a developer building out a multi-lot project, a homeowner constructing a new single-family residence from the ground up, or a property owner adding a private, self-contained living space, a manufactured or modular home delivers a cost-effective, high-quality solution. From scaling a development to housing a family member or generating rental income, it’s a smart investment that increases property value and puts space to work.
Every prefab unit we deliver is built to the highest standards at the factory — and our manufactured units arrive HUD-approved. Once installed on a permanent foundation, each home undergoes all required on-site inspections to ensure full compliance with local and state codes, and can be legally registered as real property through Form 433A.
Whether your project is a single-family residence, a multi-family build, or an ADU, you’re investing in durable, high-quality construction designed to stand the test of time.
It's the first question everyone asks — and we answer it with clear, itemized estimates that break down the installation scope and every phase of the project. As a solid ballpark, the combined cost of the home itself plus installation and construction work typically runs $250–$325 per square foot, depending on site conditions, finishes, and project scope. For manufactured homes, the unit is purchased through a licensed dealer — and as a Mobile Home Dealer ourselves, we can handle that for you directly.
We begin by understanding your goals and project needs — whether you want a contractor to perform a single scope of work or to provide full-service turnkey delivery. Licensed as a B General Building Contractor and a C-47 Manufactured Housing Contractor, we manage the entire process: permits, site prep, foundation, utilities, and setup. Expect a property visit within 2–3 days of your call and a detailed estimate shortly after.
How Long Does It Take?
Prefab structures come together much faster than traditional stick-built homes. A typical timeline looks like this:
Permitting: 25-60 weeks (varies by city/county)
Factory Build and Delivery: 6-10 weeks (can run concurrently with permitting, site prep, utility work, and foundation work)
Site Prep and Foundation: 2-4 weeks
Installation and Finishes: 4-6 weeks
Final Inspections and Touch-ups: 1-2 weeks
Most projects wrap up in 6–15 months, with local permitting and site conditions driving where you land in that range.
We are manufactured and modular home installers. Our homes are built offsite in factories using premium materials and expert craftsmanship — manufactured units to strict HUD standards, and modular units to the same state and local building codes as site-built homes. Once delivered, BuiltADU handles the full scope of permitting, site prep and grading, utility work, foundation work, setup, and construction work both inside and outside the home once it’s on the foundation. The result is a durable, long-lasting home built to the highest standards, from the factory floor to the final walkthrough.
From planning and permitting to site prep, utility and foundation work, delivery, installation, and final touch-ups, we handle every detail so you don’t have to.
One team, one point of contact. We handle the entire architectural scope — from design through securing your building permit with the city or county — then coordinate the factory and transportation and manage all on-site construction, keeping your project on schedule and stress-free.
Escrow (if you purchase the home through our Mobile Home Agents dealership), warranty, inspections, and HCD documentation — we manage it all to ensure your prefab home is fully registered as real property.
Got questions? Concerns? We're here every step of the way to guide, inform, and make sure you're completely confident and satisfied.
No vague numbers, no surprise costs. From day one, you'll get transparent, line-by-line estimates — so you know exactly what you're paying for and what you're getting.
Manufactured homes are factory-built to HUD standards and modular homes to building codes — both delivered ready to install. Less time, fewer inspections, and far less disruption to your property.
Call, text, email, or meet in person — whatever works for you, we keep the process smooth, responsive, and personal.