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Best Prefab and Modular ADU Companies in California (2026): 12 Compared and Scored

Twelve prefab and modular ADU companies that sell to California homeowners, compared on what a homeowner actually needs to know: the real installed price, what that price leaves out, how long it takes, and whether the company is still standing.

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

The short answer

A prefab ADU in California costs about $155,000 to $498,800 all-in as of September 2026, based on the companies that publish a full installed price. Of the 12 companies we scored, Perpetual Homes scores highest, on low home prices and wide coverage, Abodu is the only one we reviewed that publishes exactly what its price leaves out, and USModular and Boxabl publish the lowest turnkey prices. Two names people still search for, Connect Homes and Mighty Buildings, no longer sell ADUs to homeowners.

Quick picks

8.1/ 10
Highest score overallPerpetual Homes ADU
7.8/ 10
Know the full price up frontAbodu
7.8/ 10
Low turnkey price, Southern CaliforniaUSModular
7.8/ 10
Published turnkey price, small unitBoxabl
7.9/ 10
Steel-built, design-ledSamara Backyard
7.8/ 10
Turnkey in LA, Bay Area and San DiegoVilla Homes

All 12 companies, side by side

Prices and terms as published by each company, checked September 26, 2026.

Prefab ADU companies in California compared
#CompanyScorePricePer sq ftTime to move-inBest for
1Perpetual Homes ADUPerpetual Homes ADU review8.1Homes from $123,000 (440 sq ft) to $170,000 (1,173 sq ft); all-in from the mid $200,000s, per the company$145 to $280 (home only, before site work)About 2 to 4 months on site after delivery, per the company; permitting is extraLow home prices and many floor plans across 24 counties
2Samara BackyardSamara Backyard review7.9Units from $152,000 (studio) to $277,000 (950 sq ft), plus installation$292 to $362 (unit only, before installation)About 8 to 9 months, including about 5 months of permittingA design-led, steel-built unit from a well-funded maker
3AboduAbodu review7.8All-in from $298,800 (385 sq ft studio) to $498,800 (1,195 sq ft)$417 to $776 (all-in)About 9 to 12 months including permits; installation in one dayKnowing the whole number before you sign
4BoxablBoxabl review7.8Turnkey $185,000 to $200,000 for the California-approved 1- and 2-bedroom (promotional pricing)$256 to $277 (turnkey, California-approved models)About 2 months from the factory, plus permittingA clear, published turnkey price on a small unit
5USModularUSModular review7.8Turnkey from $155,000 in San Diego (tiny ADUs from $145,000)Not listed per model6 to 9 months from permit submissionA budget turnkey ADU in the Inland Empire and San Diego
6Villa HomesVilla Homes review7.8Turnkey from about $225,000About $258 to $442 (from 2023 model prices)9 to 12 monthsA turnkey build with many floor plans in Los Angeles, the Bay Area and San Diego
7CoverCover review7.8Quoted per design, with no published price list. One owner on Reddit reported about $500 per sq ftAbout $500 (one owner report)As little as 4 months for an ADU; 6 to 8 weeks on siteFire-zone lots and fully custom designs in Southern California
8DveleDvele review7.6ADU-size models from $167,400 (532 sq ft) to $283,200 (900 sq ft), factory priceAbout $315 (factory price only)6 to 12 months to move-inA high-performance steel home and the longest structural warranty here
9StudioHOME (formerly Studio Shed)StudioHOME review7.6Finished models from $98,029 (308 sq ft) to $191,523 (1,000 sq ft), plus installation; shell kits from $44,304$192 to $318 (kit only)Kits ship in 4 to 6 weeks; permitting is separateSmall studios and hands-on owners
10Azure Printed HomesAzure Printed Homes review7.6Models from $89,900 (360 sq ft) to $219,900 (900 sq ft)$244 to $250 (unit only)8 to 23 days from factory to installed, per the company; permits are extraEarly adopters of new materials
11LiveLargeLiveLarge review7.6Models from $140,000 (350 sq ft) to $355,000 (1,190 sq ft), before installation$298 to $400 (unit only, before installation)4 to 6 weeks on siteA steel-frame ADU in Silicon Valley
12Plant PrefabPlant Prefab review7.5Quoted per projectNot publishedDesign 4 to 6 weeks, fabrication 8 to 16 weeks, site work 8 to 16 weeks, finish 6 to 12 weeksArchitect-led custom projects

Scores run from 7.0 to 10 (every listed company starts at 7.0). Every company here cleared the same entry bar, so the differences are about fit, not about good and bad. How we score.

Prefab ADU company reviews

1. Best for low home prices and many floor plans across 24 counties

Perpetual Homes ADU

8.1/ 10

An authorized Skyline Homes dealer in Danville that sells factory-built ADUs across 24 California counties and coordinates the project from design to delivery.

Price
Homes from $123,000 (440 sq ft) to $170,000 (1,173 sq ft); all-in from the mid $200,000s, per the company
What the price covers
Catalog prices are the home only. The all-in estimate adds a raised foundation, standard utilities, $9,500 of planning and a $20,000 allowance for city fees
Price per sq ft
$145 to $280 (home only, before site work)
Time to move-in
About 2 to 4 months on site after delivery, per the company; permitting is extra
Serves
24 California counties, including the Bay Area, Sacramento, the Central Coast, the Central Valley and Los Angeles
How it is built
Factory-built by Skyline Homes (manufactured housing), set on a raised foundation
Warranty
1-year limited plus a 6-year structural warranty through Assurant
Owner feedback
BBB A+ (accredited), 0 complaints. Birdeye 4.6 from 16 reviews.
Status
Operating

What we like

  • An all-in figure that already includes fees and tax
  • 24 named counties, the longest service list here
  • A 1-year limited warranty plus 6 years of structural cover through Assurant
  • A published payment schedule and named financing partners

Worth knowing

  • Site work is done by a licensed contractor you engage, since Perpetual is a dealer rather than a general contractor
  • Its site quotes three different starting prices, so ask for a written all-in quote
  • Total installed costStandout
  • Price transparencyGood
  • Time to move-inStandard
  • Build methodStandard
  • WarrantyGood
  • Owner feedbackGood
  • Company stabilityGood
  • California coverageStandout
  • Design choiceGood
Visit Perpetual Homes ADURead the full Perpetual Homes ADU review

Sources: Perpetual Homes: areas served · Perpetual Homes: models · Perpetual Homes: financing · BBB profile · Perpetual Homes: model catalog · Perpetual Homes: 10-step process

2. Best for a design-led, steel-built unit from a well-funded maker

Samara Backyard

7.9/ 10

A steel-framed ADU from Samara, a Redwood City company backed by Airbnb that builds in its own factory.

Samara Backyard XL 8, an 800 sq ft two-bedroom steel-clad ADU, in a backyard
Photo: Courtesy of Samara
Price
Units from $152,000 (studio) to $277,000 (950 sq ft), plus installation
What the price covers
The unit. Installation is quoted after a site visit and covers design, permits, site prep, foundation, utilities, crane and decks
Price per sq ft
$292 to $362 (unit only, before installation)
Time to move-in
About 8 to 9 months, including about 5 months of permitting
Serves
California
How it is built
Built as complete rooms in the factory (volumetric modular), with a cold-formed steel frame and California's factory-built housing seal from HCD, the state housing department
Warranty
In the purchase contract; ask for it before signing
Owner feedback
Google 5.0 from 15 reviews. BBB A+, 0 complaints. TIME Best Inventions 2024.
Status
Operating and expanding

What we like

  • A steel volumetric build with state factory approval
  • Its own factory and strong financial backing
  • Clear published unit prices
  • Financing with no payments for 180 days, through Samara Finance

Worth knowing

  • Installation is quoted per site, so the all-in number comes later
  • Five models, so less room to customize
  • Total installed costGood
  • Price transparencyGood
  • Time to move-inGood
  • Build methodStandout
  • WarrantyStandard
  • Owner feedbackGood
  • Company stabilityStandout
  • California coverageGood
  • Design choiceStandard
Visit Samara BackyardRead the full Samara Backyard review

Sources: Samara: models and prices · Samara: how it works · Samara: financing · Samara acquires Mexicali factory (GlobeNewswire) · BBB profile

3. Best for knowing the whole number before you sign

Abodu

7.8/ 10

Abodu sells factory-built backyard homes with a fixed, itemized all-in price in the Bay Area and Greater Los Angeles.

Good to know: Abodu's own site says Bobby Shokri acquired the company in 2025, after reports that summer that the original company had stopped paying some vendors. We found no bankruptcy filing. If you signed before the change, confirm in writing who holds your contract and deposit.

Price
All-in from $298,800 (385 sq ft studio) to $498,800 (1,195 sq ft)
What the price covers
Design, engineering, permits, sprinklers, delivery, foundation, site work, trenching up to 50 ft, crane up to 100 ft and a project manager
Price per sq ft
$417 to $776 (all-in)
Time to move-in
About 9 to 12 months including permits; installation in one day
Serves
The San Francisco Bay Area and Greater Los Angeles, 90+ cities
How it is built
Factory-built modular, to California's state standard for factory-built housing (HCD)
Warranty
Ask for terms in writing
Owner feedback
Birdeye 4.0 from 81 reviews. Yelp 3.5 from 34. BBB 0 complaints.
Status
Operating under new ownership

What we like

  • The most complete, itemized all-in pricing in California
  • A written list of exactly what is quoted separately
  • Pre-approved plans in San Jose and Sonoma County
  • A one-day installation

Worth knowing

  • Higher per square foot than most, especially on small models
  • Some owners report delays, so agree dates in the contract
  • Total installed costStandard
  • Price transparencyStandout
  • Time to move-inGood
  • Build methodGood
  • WarrantyStandard
  • Owner feedbackStandard
  • Company stabilityStandard
  • California coverageGood
  • Design choiceStandard
Visit AboduRead the full Abodu review

Sources: Abodu: pricing · Abodu: fixed pricing and exclusions · Abodu: about (ownership) · August 2025 vendor report (LinkedIn) · Abodu: process · San Jose pre-approved Abodu plans

4. Best for a clear, published turnkey price on a small unit

Boxabl

7.8/ 10

Boxabl is a Las Vegas manufacturer whose folding Casita units ship on a truck and unfold on site, with California approval for its one- and two-bedroom models.

A Boxabl Casita finished with an adobe-style front at Boxabl headquarters
Photo: GrowTheWorld9 / Wikimedia Commons, CC BY-SA 4.0 (license)

Good to know: Boxabl's own SEC filing notes financial risk, so paying in stages tied to delivery is sensible.

Price
Turnkey $185,000 to $200,000 for the California-approved 1- and 2-bedroom (promotional pricing)
What the price covers
Permits, survey, engineering, utility hookups, foundation, installation, shipping, crane and final inspection, per the company
Price per sq ft
$256 to $277 (turnkey, California-approved models)
Time to move-in
About 2 months from the factory, plus permitting
Serves
California approval for the 1-bedroom and 2-bedroom Casita; California installs are just starting
How it is built
Folding factory-built modules
Warranty
1-year manufacturer warranty plus a 6-year extended warranty
Owner feedback
Google 4.7 from 872 reviews for the Las Vegas factory. BBB rating F with 9 closed complaints.
Status
Operating, listed on Nasdaq (BXBL) since July 2026

What we like

  • A turnkey price published for every model
  • Unit and turnkey prices shown side by side
  • A public company, so its finances are disclosed
  • A 1-plus-6-year warranty

Worth knowing

  • Early in California, with the studio not yet confirmed for the state
  • Little room to customize the fixed Casita shape
  • Total installed costStandout
  • Price transparencyStandout
  • Time to move-inGood
  • Build methodStandard
  • WarrantyGood
  • Owner feedbackStandard
  • Company stabilityStandard
  • California coverageStandard
  • Design choiceStandard
Visit BoxablRead the full Boxabl review

Sources: Boxabl: Casita Studio · Boxabl: Casita Two Bedroom · Boxabl SEC filing, Q2 2026 · Boxabl expands California general contracting (Nasdaq) · BBB profile

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

USModular

7.8/ 10

A Calimesa modular dealer in business since 2009, selling turnkey ADUs across Southern California.

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.

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 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
  • Total installed costStandout
  • Price transparencyGood
  • Time to move-inGood
  • Build methodStandard
  • WarrantyStandard
  • Owner feedbackStandard
  • Company stabilityGood
  • California coverageStandard
  • Design choiceGood
Visit USModularRead the full USModular review

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

6. Best for a turnkey build with many floor plans in Los Angeles, the Bay Area and San Diego

Villa Homes

7.8/ 10

Villa is a California ADU builder that designs units, has them built in partner factories and handles the project from permits to move-in.

Good to know: Villa now describes itself as a homebuilding platform that works with a network of off-site factories and also builds its own neighborhoods, under CEO Sean Roberts.

Price
Turnkey from about $225,000
What the price covers
Permits, site and foundation prep, construction, appliances, utility hookups and installation, per Dwell
Price per sq ft
About $258 to $442 (from 2023 model prices)
Time to move-in
9 to 12 months
Serves
Los Angeles, the Bay Area and San Diego
How it is built
Kiln-dried wood frame, built off-site by partner factories and craned in
Warranty
A standard warranty; ask for the length in writing
Owner feedback
Google 4.7 from 15 reviews. BBB A+ (accredited since January 2026), 0 complaints.
Status
Operating

What we like

  • Pre-approved plans in Los Angeles and San Jose
  • A turnkey price that covers permits and site work
  • Many floor plans plus a design studio
  • Strong owner ratings and a clean BBB record

Worth knowing

  • Current prices were not available for us to check, so get a written quote
  • The business is widening beyond backyard ADUs, so ask who will run your project
  • Total installed costGood
  • Price transparencyStandard
  • Time to move-inGood
  • Build methodGood
  • WarrantyStandard
  • Owner feedbackGood
  • Company stabilityGood
  • California coverageStandout
  • Design choiceGood
Visit Villa HomesRead the full Villa Homes review

Sources: Dwell: Villa prefab California ADU builder · Villa delivers first homes at Acacia Village (Newswire) · San Jose pre-approved ADU plans (ADU Plan Finder) · BBB profile

7. Best for fire-zone lots and fully custom designs in Southern California

Cover

7.8/ 10

A Gardena company that designs custom homes and ADUs and builds them from non-combustible steel panels made in its own factory.

Price
Quoted per design, with no published price list. One owner on Reddit reported about $500 per sq ft
What the price covers
Design through construction, with a refund if permits cannot be obtained
Price per sq ft
About $500 (one owner report)
Time to move-in
As little as 4 months for an ADU; 6 to 8 weeks on site
Serves
Ten Southern California counties, from San Luis Obispo to San Diego and Imperial
How it is built
Panelized light-gauge steel, non-combustible, no crane needed
Warranty
Ask for terms in writing
Owner feedback
Google 4.7 from 23 reviews.
Status
Operating, with a growing focus on custom homes and fire rebuilds

What we like

  • Non-combustible steel construction, strong for wildfire areas
  • Fully custom design
  • A full refund if permits cannot be obtained
  • Its own Los Angeles-area factory

Worth knowing

  • A premium price, and no published price list
  • Southern California only
  • Total installed costStandard
  • Price transparencyStandard
  • Time to move-inGood
  • Build methodStandout
  • WarrantyStandard
  • Owner feedbackGood
  • Company stabilityGood
  • California coverageStandard
  • Design choiceStandout
Visit CoverRead the full Cover review

Sources: Cover: FAQ (service area) · Owner report on Reddit · Cover: our process · Cover completes first Palisades rebuild (PR Newswire) · CSLB license 1039029 · Cover completes first ADU in Redondo Beach (PR Newswire)

8. Best for a high-performance steel home and the longest structural warranty here

Dvele

7.6/ 10

A steel modular maker, now based in Mesa, Arizona, that sells finished modules for your own contractor to install.

A Dvele steel modular home at dusk in Ventura, California (a full-size home, not an ADU)
Photo: Courtesy of Dvele
Price
ADU-size models from $167,400 (532 sq ft) to $283,200 (900 sq ft), factory price
What the price covers
The home, including electrical, plumbing, mechanical, finishes and appliances. Delivery, site work, installation and $15,000 to $100,000 of design and permit fees are extra
Price per sq ft
About $315 (factory price only)
Time to move-in
6 to 12 months to move-in
Serves
California, as a product you install through your own contractor; currently prioritizing Altadena fire rebuilds
How it is built
Built as complete rooms in the factory (volumetric modular), with a steel frame
Warranty
2-year fit and finish, 5-year on the building shell, 10-year structural
Owner feedback
BBB A+, 0 complaints.
Status
Operating, now headquartered in Mesa, Arizona

What we like

  • The longest published structural warranty here (2, 5 and 10 years)
  • Solar and battery storage available
  • A steel, high-performance build
  • Model prices published

Worth knowing

  • Sold as a product, so you manage the site contractor
  • Site work and design and permit fees are on top of the factory price
  • Total installed costStandard
  • Price transparencyGood
  • Time to move-inGood
  • Build methodStandout
  • WarrantyStandout
  • Owner feedbackStandard
  • Company stabilityGood
  • California coverageStandard
  • Design choiceStandard
Visit DveleRead the full Dvele review

Sources: Dvele: homes · Dvele: FAQ · Dvele: Altadena rebuild program

9. Best for small studios and hands-on owners

StudioHOME (formerly Studio Shed)

7.6/ 10

The company formerly called Studio Shed sells panelized kits, installed by its network of certified assemblers or by you.

Price
Finished models from $98,029 (308 sq ft) to $191,523 (1,000 sq ft), plus installation; shell kits from $44,304
What the price covers
The kit. Installation, foundation, delivery and permits are extra
Price per sq ft
$192 to $318 (kit only)
Time to move-in
Kits ship in 4 to 6 weeks; permitting is separate
Serves
Northern California and, per a new company page, Los Angeles, Orange and San Diego counties
How it is built
Panelized kit, no crane, Title 24 and zero-net-energy ready
Warranty
1 year on materials and workmanship
Owner feedback
Google 4.3 from 63 reviews. BBB A+, 1 complaint.
Status
Operating, renamed from Studio Shed in March 2025

What we like

  • Kit prices published for every model
  • A long track record, with more than 6,000 projects
  • No crane needed, which helps on tight lots
  • Choose DIY, a shell, or a fully finished install

Worth knowing

  • Installation and site work are priced separately
  • Some buyers report difficulty finding a local installer
  • Total installed costGood
  • Price transparencyGood
  • Time to move-inGood
  • Build methodGood
  • WarrantyStandard
  • Owner feedbackGood
  • Company stabilityGood
  • California coverageGood
  • Design choiceGood
Visit StudioHOMERead the full StudioHOME review

Sources: StudioHOME: models · StudioHOME: Northern California · Studio Shed becomes StudioHOME (PR Newswire) · StudioHOME: Southern California · StudioHOME: process

10. Best for early adopters of new materials

Azure Printed Homes

7.6/ 10

A Gardena company that 3D-prints ADUs from recycled polymer, with a claimed install time measured in days.

Price
Models from $89,900 (360 sq ft) to $219,900 (900 sq ft)
What the price covers
The unit; confirm what installation adds
Price per sq ft
$244 to $250 (unit only)
Time to move-in
8 to 23 days from factory to installed, per the company; permits are extra
Serves
California, per the company
How it is built
3D-printed recycled polymer with fiberglass, plus steel
Warranty
10 years on materials and workmanship, plus 15 years on the UV coating, per the company
Owner feedback
Google 5.0 from 5 reviews. Named to TIME Best Inventions 2025.
Status
Operating, raising funds through Wefunder

What we like

  • Low unit prices
  • Very fast installation, per the company
  • A 10-year warranty
  • Named to TIME Best Inventions 2025

Worth knowing

  • A newer building method with a short track record
  • Check which models are on your city's approved list
  • Total installed costGood
  • Price transparencyStandard
  • Time to move-inGood
  • Build methodStandard
  • WarrantyGood
  • Owner feedbackStandard
  • Company stabilityStandard
  • California coverageGood
  • Design choiceStandard
Visit Azure Printed HomesRead the full Azure Printed Homes review

Sources: Azure: models · Azure mid-year milestones (GlobeNewswire) · TIME Best Inventions 2025 · Azure: FAQ

11. Best for a steel-frame ADU in Silicon Valley

LiveLarge

7.6/ 10

A San Jose maker of steel-frame, fire-resistant ADUs with a published model price list.

Price
Models from $140,000 (350 sq ft) to $355,000 (1,190 sq ft), before installation
What the price covers
The unit. LiveLarge then gives one fixed all-in quote covering permits, site work, delivery and installation after a site review
Price per sq ft
$298 to $400 (unit only, before installation)
Time to move-in
4 to 6 weeks on site
Serves
The Bay Area, with deliveries also listed in Altadena and Los Angeles
How it is built
Steel frame, fire-resistant for wildland-urban interface areas, with a state (HCD) insignia on each unit, per the company
Warranty
10-year structural, 5-year doors and windows, 2-year plumbing and electrical
Owner feedback
Google 5.0 from 15 reviews.
Status
Operating

What we like

  • A published price for every model
  • Steel frame, built for fire-prone areas
  • A 10-year structural warranty
  • One fixed all-in quote after a site review

Worth knowing

  • The all-in number comes after a site review
  • Less independent review history so far
  • Total installed costGood
  • Price transparencyStandard
  • Time to move-inGood
  • Build methodGood
  • WarrantyGood
  • Owner feedbackGood
  • Company stabilityStandard
  • California coverageGood
  • Design choiceGood
Visit LiveLargeRead the full LiveLarge review

Sources: LiveLarge: models and prices · LiveLarge: FAQ (warranty, HCD) · LiveLarge: models

12. Best for architect-led custom projects

Plant Prefab

7.5/ 10

A large California factory that builds custom and LivingHome designs, mostly through architects and general contractors.

Price
Quoted per project
What the price covers
Varies by project and by the builder you work with
Price per sq ft
Not published
Time to move-in
Design 4 to 6 weeks, fabrication 8 to 16 weeks, site work 8 to 16 weeks, finish 6 to 12 weeks
Serves
California, mainly through general contractors and architects
How it is built
Hybrid panels and modules, with third-party state-certified inspection
Warranty
Ask for terms in writing
Owner feedback
Google 4.7 from 21 reviews.
Status
Operating

What we like

  • A large factory in California
  • Flexible panel and module system
  • Custom and LivingHome designs
  • A clear, published phase-by-phase timeline

Worth knowing

  • Usually bought through an architect or contractor rather than directly
  • No published prices
  • Total installed costStandard
  • Price transparencyStandard
  • Time to move-inGood
  • Build methodStandout
  • WarrantyStandard
  • Owner feedbackGood
  • Company stabilityGood
  • California coverageGood
  • Design choiceStandout
Visit Plant PrefabRead the full Plant Prefab review

Sources: Plant Prefab: models · Plant Prefab: wildfire help (timeline) · The Planning Report interview, February 2026

Also an option: a manufactured-home ADU through a dealer

Large manufactured-home builders such as Cavco (Palm Harbor, Fleetwood) and Skyline Champion (Silvercrest) make ADU-size models in California factories, sold through local dealers. Base prices listed by one dealer run from $78,607 to $119,173 for 744 to 1,173 sq ft, before delivery, setup, tax and site work. They are built to the federal HUD code, the national standard for manufactured homes, and must sit on a permanent foundation to count as an ADU. The all-in cost depends on the dealer and your site, so compare two dealer quotes. We do not score this route because terms vary dealer by dealer.

Sources: Homes Direct ADU list · Silvercrest 790 ADU

Prefab ADU companies by region: Los Angeles, Bay Area, San Diego and Sacramento

Based on the service areas each company publishes. Companies marked statewide still quote per site, so confirm your address before a deposit.

Prefab ADU companies serving each California region
RegionCompanies that list it
Los AngelesAbodu, Villa Homes, Cover, Perpetual Homes ADU, USModular, LiveLarge, StudioHOME (USModular serves parts of LA County.)
Bay Area and Silicon ValleyAbodu, Villa Homes, Perpetual Homes ADU, LiveLarge, StudioHOME
San DiegoVilla Homes, USModular, Cover, StudioHOME
Orange County and the Inland EmpireUSModular, Cover, StudioHOME
Sacramento and the Central ValleyPerpetual Homes ADU, StudioHOME
Statewide or through your own contractorSamara Backyard, Boxabl, Azure Printed Homes, Plant Prefab, Dvele

Which prefab ADU companies closed or changed?

Several names that still show up in older lists have closed, been sold or changed what they sell. This is what we found in public records and reporting, checked September 26, 2026.

Prefab ADU company status changes
CompanyStatusWhenWhat happened
Connect HomesClosedJanuary 2025Home EC Inc. (doing business as Connect Homes) went through an assignment for the benefit of creditors, an out-of-court liquidation. Its old domain now redirects to a "Connect Shelters" site whose operator we could not confirm. SF Chronicle, via Allen Matkins, Dwell
Mighty BuildingsSold, no longer sells homes to homeowners2025The 3D-printing company was sold and now operates as a LUMUS brand selling wall systems. Mighty Buildings: about, 3D Printing Industry
AboduOperating under new ownership2025Acquired by Bobby Shokri after reports in August 2025 that the original company had stopped paying some vendors. No bankruptcy filing found. Abodu: about
Villa HomesOperating, broader model2026Now a homebuilding platform using partner factories and building its own neighborhoods, under CEO Sean Roberts. Still offers ADUs. Newswire
Studio ShedRenamed StudioHOMEMarch 2025Same company, new name. PR Newswire
DveleOperating, moved headquarters2026Headquarters and a new factory in Mesa, Arizona. Blu Homes is now part of Dvele. Dvele: contact
CottageAbsorbed by RenoFiDate not confirmedThe ADU design and permitting service is now part of RenoFi. Cottage on LinkedIn
Avava SystemsClosedDate not confirmedThe flat-pack ADU maker no longer operates. Dwellito
Anchored Tiny HomesClosedJuly 2024The Sacramento ADU builder shut down abruptly. ABC7
VeevClosedNovember 2023The panelized home builder shut down. The Real Deal
KaterraClosedJune 2021Filed for Chapter 11 and wound down US operations. ENR
NestronOperating, no California ADU approval stated2026Units are made in Shenzhen and sold from a Cabazon showroom. We found no California factory-built approval, so we do not rank it. Nestron: about

How to protect your deposit

  • California caps a home-improvement down payment at $1,000 or 10% of the contract, whichever is less.
  • Ask for a payment schedule tied to delivery and installation, not to the calendar.
  • Look up the company's license, bond and workers' comp on the CSLB website before you sign.

Unit price vs all-in price

Prefab prices are published in two different ways, and mixing them up is an easy way to under-budget. Some companies publish a unit price: the building, delivered or ready to ship. Samara, Dvele, StudioHOME, LiveLarge and Azure work this way. Others publish an all-in price that includes permits, foundation, utility connections and installation: Abodu, Boxabl's turnkey option, USModular, Perpetual Homes and Villa.

The gap between the two is site work. Abodu, the only company here that itemizes it, prices installation at $64,000 to $105,000 depending on the model, and still lists a survey, long trenching runs, long crane reaches, tree removal and sales tax as extras. On the published all-in prices, a finished prefab ADU runs roughly $256 to $776 per square foot, with small studios at the top of that range because site work costs about the same whatever the size.

For a line-by-line look at what 13 companies publish and what their prices leave out, read our guide to prefab ADU cost in California. For the full ADU picture, including garage conversions and site-built units, see our California ADU guide.

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

How we score

To be listed, a company must be operating, sell factory-built ADUs to California homeowners, and hold state approval or build to California code. Every listed company starts at 7.0. It can earn up to 3 more points across nine criteria, in proportion to each criterion's weight. Information a company does not publish counts as neutral, never against it. No company pays to be listed or to change its score, and scores are updated when the facts change.

Scoring criteria and weights
CriterionWeightWhat we look at
Total installed cost20%How far a dollar goes once the unit is actually installed and permitted, from published all-in prices where they exist.
Price transparency15%Whether a homeowner can see a price, and what it covers, before a sales call.
Time to move-in10%The published window from contract to a finished unit.
Build method10%A proven factory method with state approval, and how well the finished shell (walls, roof, windows) holds up.
Warranty10%Published warranty terms, especially structural coverage.
Owner feedback10%What owners say on Google, BBB and other public review sites.
Company stability10%Track record, funding and ownership, read from public records and news.
California coverage10%How much of California the company serves, and pre-approved plans in city programs.
Design choice5%How many plans there are and how far they can be changed.

Sources are company websites, pricing and FAQ pages, SEC filings, BBB, Google reviews, city pre-approved plan lists and news reporting, each linked beside the fact it supports. Found something out of date? Email editor@therenology.com and we will check it.

Change log

  • : First published. 12 companies scored, 12 status changes tracked.
  • : Added full reviews for the other eight companies, a price per sq ft column and photos. Corrected Perpetual Homes (dealer, home-only catalog prices), Dvele (solar now optional) and LiveLarge (10-year structural warranty).
  • : Editorial pass: Boxabl price floor now uses its California-approved models, Perpetual Homes warranty wording corrected, regions table and new FAQs added.

Frequently asked questions

How much does a prefab ADU cost in California?

Published all-in prices in California run from about $155,000 to $498,800 as of September 2026, from USModular's turnkey starting price to Abodu's 1,195 sq ft three-bedroom. Unit-only prices start lower, from about $90,000, but site work, foundation, utilities and permits come on top. Abodu, the only company we reviewed that itemizes it, prices installation at $64,000 to $105,000.

Which prefab ADU company is the best in California?

It depends on what you need. In our September 2026 review, Perpetual Homes scored highest overall for a managed all-in build, Samara for a steel-built design-led unit, Abodu for knowing the full price up front, and USModular or Boxabl for the lowest published turnkey prices.

What are the drawbacks of prefab ADUs?

Four are worth knowing. Site work, foundation and utilities still cost about as much as for a site-built ADU and are often priced separately. Most makers offer a handful of fixed floor plans. A crane or truck needs access to your yard. And several prefab companies have closed in recent years, so check a company's license and ask how your deposit is held.

What is the difference between a prefab and a modular ADU?

Prefab is the umbrella term for any ADU built mostly in a factory. A modular ADU is one kind: it arrives as complete rooms (volumetric modules), like Samara, Abodu or Dvele. Other prefab ADUs arrive as wall and roof panels assembled on site, like Cover or StudioHOME, or are built to the federal HUD code for manufactured homes.

Are prefab ADUs worth it?

For many California lots, yes. A factory-built unit usually spends weeks on site instead of months, and several makers publish prices up front. The savings are smaller than the sticker suggests, because site work, foundation and utilities cost about the same as for a site-built ADU.

What is the cheapest way to get a prefab ADU in California?

The lowest published turnkey starting prices are USModular's (from $155,000 in Southern California) and Boxabl's ($185,000 to $200,000 for its California-approved models). Manufactured-home ADUs through dealers can have lower unit prices, but delivery, setup and site work are extra.

Is it cheaper to build or prefab an ADU?

Prefab is usually faster, and sometimes cheaper. Site-built ADUs in California commonly run $300 to $550 per sq ft. Published prefab all-in prices range from about $256 to $776 per sq ft, depending on size and maker.

Do prefab ADUs need a foundation?

Yes. A California ADU sits on a permanent foundation, and your city permits it along with the utility connections. Some makers include it in the price; others quote it separately.

What is the $40,000 grant in California for ADUs, and is it still available?

It was the CalHFA ADU Grant Program, which paid up to $40,000 toward pre-construction costs such as design, permits and impact fees. It has been fully allocated since December 2023 and is not accepting applications. Some cities and counties run their own programs, so check with your local housing department.

What happened to Connect Homes?

Connect Homes closed in January 2025 through an assignment for the benefit of creditors, an out-of-court liquidation, as reported by the San Francisco Chronicle and Dwell.

How do I protect my deposit with a prefab ADU company?

California caps a home-improvement down payment at $1,000 or 10% of the contract, whichever is less. Ask for a payment schedule tied to delivery and installation milestones, and check the company's license on the CSLB website before signing.