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USModular ADU Review (2026): Prices, Timeline and License

7.8/ 10

By the Renology editorial team · Reviewed by Dror Gigi, Co-Founder · Facts checked

Best for a budget turnkey ADU in the Inland Empire and San Diego

USModular, which also sells as MyADU4Less, is a Calimesa design-build company that has installed manufactured and modular homes in Southern California since 2009. Its San Diego all-in pricing starts at $155,000 for a prefab ADU and $145,000 for a tiny home ADU, including design, permits, a raised pier foundation, delivery, installation and utility connections.

Good to know: The state contractor board lists a completed 2026 citation on USModular's license, for requesting payment ahead of work completed and for a home improvement contract issue. The license is active through February 2028. The CSLB page does not show the details of the case.

USModular at a glance

Price
Turnkey from $155,000 in San Diego (tiny ADUs from $145,000)
What the price covers
Design, permits and fees, raised pier foundation, transport, installation and utility connections to existing lines
Price per sq ft
Not listed per model
Time to move-in
6 to 9 months from permit submission
Serves
Riverside, San Bernardino and San Diego counties, plus parts of Los Angeles and Orange County
How it is built
Built to California's modular code or the federal HUD code for manufactured homes
Warranty
Ask for terms in writing
Owner feedback
BBB A+, 1 closed complaint. Birdeye 4.1 from 50 reviews.
Status
Operating since 2009

What a USModular ADU costs

USModular publishes several price points, and each means something different. A 400 sq ft HUD-code unit starts at $64,200, and site construction for it starts at $46,500 on a flat lot, before permits, fees and civil engineering. In San Diego the company quotes all-in starting prices of $145,000 for a tiny home ADU and $155,000 for a prefab ADU.

Crane sets, decks, landscaping, retaining walls, tile roofs, solar and demolition are listed as extras. Ask for an all-inclusive quote for your lot, which the company says it offers for standard sites.

Plans and timeline

The catalog shows roughly 50 plans from 395 to 1,176 sq ft, up to three bedrooms, built to either the federal HUD code for manufactured homes or California's modular code. Most projects take 6 to 9 months end to end, with the factory build, delivery and installation finishing in about 3 months once permits are approved.

License and track record

USModular's contractor license (CSLB 943047) is active through February 2028, with a $25,000 bond. The CSLB page also lists a citation dated August 2026, now completed, for requesting payment ahead of work completed and for a home improvement contract issue. The details of the case are not shown.

Owner feedback is mixed but mostly positive: 4.1 on Birdeye from about 50 reviews and an A+ BBB rating. A payment schedule tied to completed work is a good idea with any builder.

What we like, and what is worth knowing

What we like

  • One of the lowest turnkey starting prices, including permits and foundation
  • 17 years in business
  • More than 100 floor plans
  • A clear list of what the price includes

Worth knowing

  • Southern California only
  • A raised pier foundation may not suit every city

Choose USModular if

  • You are in Riverside, San Bernardino, San Diego or parts of LA and Orange County
  • You want one company to handle design, permits and installation
  • You want a wide choice of plans at a lower price

Look elsewhere if

  • You are outside Southern California
  • You want a steel-framed or custom-designed unit (Samara, LiveLarge or Cover)

How USModular scores

7.8 out of 10 on our published method. Every listed company starts at 7.0. Information a company does not publish counts as neutral.

  • Total installed costStandout
  • Price transparencyGood
  • Time to move-inGood
  • Build methodStandard
  • WarrantyStandard
  • Owner feedbackStandard
  • Company stabilityGood
  • California coverageStandard
  • Design choiceGood
Visit USModularCompare the best prefab ADU companies in California

The part most prefab prices leave out

Get your site work checked by a local contractor

Foundation, trenching, utility connections and crane access decide most of the gap between a sticker price and a finished ADU. A licensed local contractor can walk your yard and price that part before you sign with a factory.

Find a vetted ADU contractor

USModular FAQ

What is the typical cost of a prefab ADU in Southern California?

USModular quotes all-in starting prices of $145,000 for a tiny home ADU and $155,000 for a prefab ADU in San Diego, including design, permits, foundation, delivery, installation and utility connections.

How long does a USModular ADU take?

About 6 to 9 months end to end. After permits are approved, the factory build, delivery and installation typically finish in about 3 months.

Is USModular licensed?

Yes. CSLB license 943047 is active through February 2028. The CSLB page also shows a completed 2026 citation related to payment timing and a home improvement contract.

Does USModular offer a referral bonus?

Yes. The company advertises $1,500 for a referral that builds a new home or ADU with USModular.

Other prefab ADU reviews

Sources: USModular: Southern California ADU FAQ · USModular: backyard ADU in San Diego · CSLB license 943047 · MyADU4Less: pricing