Bay Area Pre-Fab and Modular ADU Vendors
When looking at houses with clients, I often point out that a living space can essentially be extended at relatively low cost by plunking an 8×10 studio in the backyard — not to mention the bigger investment of an ADU.
So when the 2026 Bay Area ADU Expo in San Jose popped up in my inbox, I had to trek the 60 miles to see in person what’s up with all the ADU options these days.
What a great investment in gas! The ADU Expo was a fantastic education and opportunity to meet many Accessory Dwelling Unit (ADU) builders, financing providers, and even land surveyers we have access to in California.
Having the expo in San Jose was especially meaningful; this Bay Area city was the first to legalize condoizing an ADU and house. Homeowners can then sell each building as a distinct property. (Recently Sebastopol, in Sonoma County, became the second city to legalize condo’izing ADUs. This is especially exciting as the average home buyer is more likely to find large lots with space to drop in a modular, assembled ADU than in a dense city.)
We’re in a golden age of backyard cottages.
KQED reported that a 2026 report study by UC Berkeley’s Terner Center for Housing Innovation “found factory-built housing, also known as prefab and manufactured housing, could cut costs by up to 20% and slash building timelines in half — a key innovation needed to ramp up construction and meet California’s goal of building 2.5 million homes by 2030.”
Like any hot trend, it can be a wild west when it comes to ADUs and modular building. NBA Bay Area reported in 2026 about ADU companies going out of business. Over the years, hot new concepts have come out only to run out of funding. BUYER BEWARE! Please take time to research thoroughly before committing. “If it sounds too good to be true…”
Here are a few options for adding an ADU to a backyard or creating a co-housing community:
| Pre-fab modular ADUs / Tiny Homes completely built and delivered, ready to drop in and connect to utilities at the property. Pros: Quickest delivery and easiest building process. Cons: The lot needs to accomodate the ability for a crane to raise and lower the ADU on to the foundation. Could be expensive if detaching electrical lines on the street is required. Examples: Samara, Abodu, Origin Homes | Completely built with all finishes and appliances, ready to deliver on a flatbed truck (caution: wide load!) The home gets dropped into place. Before you get all excited, know that a quick conversation with a pre-fab ADU builder is the first step. You need to have clearance for a crane to be able to lift and drop the ADU on to the building site. In urban areas, electrical wires and a small driveway may make or break the idea. Verify exactly how and if a pre-fab ADU could be installed on your lot AND how much it would cost, if avoiding electrical wires, or other barriers, are involved. |
| Panelized ADUs / Cottages / Studio Sheds built in a factory then assembled and finished on site (on your property) Pros: Quick and usually easy to get into a backyard space. Cons: Limited design options although many pre-fab ADU companies will say they can customize their designs. | Built in a factory and delivered flat packed, or in modules, for a contractor to assemble on a property. Some say even a home owner could tackle the project (moreso for studios than full ADUs). You always need to consider the plan for electrical and permitting, though. |
| Stick built ADUs — custom built units, built from scratch on site. (Here are some Bay Area builders.) Pros: Most customized to your property, potentially optimizing the space if you are fitting the building into a tight space. Cons: Most expensive (usually) and longest timeframe to build (usually). | “Stick” built refers to the typical construction built from scratch. The wood are the “sticks.” This is essentially the type of building most contractors do. If you want to build on a lot line and need to conform to a city’s lot line roof height requirements, for example, stick built might be a better option. Architects / designers such as Inspired ADUs are creating ADU designs to help lower the cost and speed up the custom ADU process. |
Pre-fab / panelized ADUs are a dynamic industry and every month brings a new development. That being said, everything I learned at the 2026 Bay Area ADU Expo is obviously subject to change. So please check for the latest information and company reviews…ideally from locals who have worked with the company you’re thinking about.
Studio Home ADUs (formerly Studio Shed)
Studio Home may sound like a new company. But no: they were formerly known as Studio Shed. Costco members and clients of mine might be familiar this name. Studio Shed‘s backyard She Shed / office sheds have been a summer feature for years.
They’ve come a long way. The Colorado-based company has expanded their selection of backyard studios to a series of ADU models and tiny homes, ready to assemble on site. One rep says they have expanded their list of vendors who can help homeowners set up their Studio Home ADU once it lands on your driveway.
Masaya Homes
Masaya’s mission is to create “sustainable homes from 100% reforested solid teak.” Their designs are straight out of a zen retreat, beautifully peaceful. Instead of a “Zoom room,” these designs, which are delivered flat-packed and assembled on your property, will work more as a “zen room.”
Masaya has a showroom off of Berkeley’s Fourth Street shopping district where you can see a studio set up along with their teak furniture. (My office is nearby if you want to meet there and chat ADUs!)
Also, if you or someone you know has a Masaya ADU or studio, I’d love to hear how it’s working out for you.
Epic Modulars — “California’s Most Affordable Homes and ADUs”
Featured in the video, Epic Modulars says they are California’s most affordable homes and ADUs. According to the owner, the company sources panelized and pre-fab Accessory Dwelling Units from factories around California. (When looking at affordability, always look at quality and warranties. If they deliver all of this, they could be instrumental in California’s construction goal!)
The company features a wide variety of panelized ADU designs. The guy I spoke with (in the video) says they are general contractors as well as having the ADU company.
The cool-looking Axis “starts at $114,000” and is a model, they say, that an entrepreneur is using to create a vacation rental camp in Northern California. Currently their website gives the all-in price at the high end of around $221K. What a beautiful design, perhaps for senior co-housing or any friends and family community? Here is a link to Epic Modular’s Google reviews.
Wellmade Panelized ADUs and Saunas
Wellmade builds their paneled ADUs and studio sheds in San Leandro, in the East Bay.
Unlike pre-fabricated ADUs, they point out “No cranes needed. Our prefabricated system eliminates the need for heavy machinery on-site.” I visited Wellmade’s factory, and there’s something nice about seeing your house being built in person. Contact them if you’re nearby!
Beyond ADUs, Wellmade has tiny models including super tiny sauna / bath houses! See Slovenian bee houses and bee tourism. Maybe we need that in California!
Samara
Samara named their ADU “Backyard” and describe it as the “meticulously crafted, smartly, customizable, completely turn key ADU.”
Samara builds the pre-fab ADUs offsite and uses a crane to drop the ADU onto the foundation on your property. Step one is to find out if that is physically possible with your property. (Over the years I’ve watched one of the early pre-fab ADU companies, Abodu, and bemoaned that my property just isn’t crane-friendly.)
This company was founded by one of the founders of Airbnb, Joe Gebbia. You can imagine the tie in of having a new ADU and potentially Airbnb’ing it to have the flexibility to also use it for friends, family and yourself.
Financing ADU’s is always a question. Leave it to an Airbnb founder to also make sure the company is a licensed mortgage broker in California. They provide their own capital for financing the loans and currently say there is 0% downpayment with no payments for six months. (Be sure to check the latest terms and also compare to other financing options, of course. A line of credit on your house might make more financial sense.)
Is there a section on Airbnb featuring Samara ADU rentals? You tell me! 🙂
Origin Studio Prefab (Pre-built) ADUs
Origin Studio, based in Indiana, builds ADUs in their factory and delivers them all over the country. The ADU’s are craned into the site. They had an ADU on display at the fair that was scheduled for delivery to a hillside home in wine country. Watch the YouTube video to hear from founder Brian English. It’s an amazing pandemic “origin” story.
English says that even when trucking them all the way from Indiana to California, it is more cost efficient than building in California.
Pacifica Tiny Homes on Wheels
Pacifica Tiny Homes has RV Tiny homes on wheels with “60 different design options and more than 120 materials choices.” If you’ve got land and like to move around and the place, these could be an affordable and flexible. The company says that its tiny homes on wheels have a lifetime warranty and are built on a custom trailer that has RV certification.
Veev by Lennar Panelized Luxury Homes
Hearing about Veev and seeing panelized, large, all electric homes was an interesting addition to the exhibitor mix. The panelized houses are built in the East Bay, in Hayward California — and they even offered a factory tour.
What’s the difference between Veev homes and an ADU? About 2000 feet. For example, they have one steel-framed house that has four bedrooms 3 1/2 baths and a two car garage with storage, all in 3045 ft.². Plus a 10 year structural warranty.
Symbihom – Pre-approved San Jose ADU Plans!
Symbihom is an especially interesting company to me as they have a number of services using customized, panelized wall panels that get assembled on your property.
Their example services include converting garages into ADUs, converting parts of a home into an ADU or JADU, building cottages, and convert commercial spaces to residential homes.
Most importantly, the website says Symbihom offers ADU plans that are pre-approved San Jose and that the company is “The only modular conversion system built to commercial specification. Check out Symbihom’s customizable floor plans.
This seems like a great model for other cities such as Oakland to adopt. (Please!)
More ADU Vendors and ADU Help
Also at the Bay Area ADU Expo were:
The company Maxable guides California homeowners through the ADU decision, design, and building process. Definitely check out their knowledge base and webinars to learn all you can.
Also look at Type Five ADUs (not at the fair)
I must give a nod to ADU company Type Five, based in Berkeley. They have an excellent tutorial on ADUs and all the ways to build them. Featured in the New York Times, this East Bay ADU builder has a goal to optimize, thus lower the price, of ADU design and construction. They are definitely worth a conversation if your property is in the Bay Area.
Yes, I admit, the green painted, corrugated metal siding has enchanted me. It could be ideal in high fire zones. Or in my backyard.
ADU Financing from Credit Unions
Several credit unions were at the fair, promoting their ADU financing products. For example Meriwest Credit Union was offering rates similar to conventional loans for ADUs up to $500,000. Their website says “Whether you’re planning a garage conversion, a backyard cottage, or a basement apartment, our ADU loan option is designed to help you finance your project with ease.”
If you talk to them or other lenders and ADU companies, I’d love to hear about your experiences.
See the full list of vendors at the Bay Area ADU Expo.
Read this disclaimer! All of this is informational / educational only. Please do your own research for options, laws, and requirements for building and renting that are specific to your town / city / county. These will differ from California laws. Also read reviews of the various companies. It’s aways important to know what may be coming down the line as far as legislation so take your time researching.
Discover more from Susie Wyshak, Real Estate Agent & Advisor | Compass Berkeley & Maine
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