Prefab ADU · California
Prefab ADU California — Factory Speed, Permit-Ready
Epic Modulars builds your ADU in a factory while permits process — cutting your total timeline nearly in half. Starting at $79K, fully permitted, all 17 cities.
The Prefab ADU Time Advantage — Why It's So Fast
Site-built ADUs wait for permits before construction starts. Prefab doesn't.
Site-Built ADU Timeline
Epic Modulars Prefab ADU
What's Included in Every Epic Modulars Prefab ADU
No hidden fees. Your all-in price covers:
Prefab ADU California FAQs
How much does a prefab ADU cost in California?
Epic Modulars prefab ADUs start at $79,000 all-in — that includes permits, factory build, delivery to your California property, installation on a permanent foundation, and a 1-year workmanship warranty. Site-built ADUs in California run $150,000–$450,000+. The difference is factory efficiency: bulk materials, consistent labor, and no weather delays.
How fast can I get a prefab ADU installed in California?
From contract signing to move-in: 6–10 months total. The factory build runs 8–12 weeks. While your unit is being built, permits are in process simultaneously. After permit approval, delivery and installation take 4–6 weeks. Contrast with site-built: construction can't start until permits are issued, often 3–6 months later.
Is a prefab ADU treated the same as site-built by California cities?
Yes. California HCD-certified factory-built ADUs are legally identical to site-built ADUs — they require the same building permits, sit on permanent foundations, and are assessed the same way for property tax. Cities cannot impose additional requirements on factory-built ADUs beyond what they require for site-built. Epic Modulars' units carry HCD certification.
Do I need a contractor to install a prefab ADU in California?
Epic Modulars handles the entire installation as part of your all-in price. We prepare the foundation, coordinate utility connections, deliver the unit, set it in place, and complete all final connections and inspections. You don't need to hire a separate contractor — we manage everything.
Can a prefab ADU speed up the California permit process?
Yes, meaningfully. California cities are more familiar with HCD-certified factory plans than with custom site-built designs. Plan check reviewers have fewer questions, and some cities (like San Jose) have streamlined programs specifically for pre-certified factory units. We've found this consistently reduces permit timelines by 2–8 weeks versus custom site-built ADU plans.
Get Your Prefab ADU Moving Now
Epic Modulars handles everything — design, permits, build, install. One call starts it all.
Start My Prefab ADU Project