Prefab Accessory Dwelling Units are coming to the North Bay
By Edward Booth
Abodu, a company focused on building prefabricated Accessory Dwelling Units, installed its first North Bay unit in unincorporated Sonoma County roughly two weeks ago. The company says more units will be coming to both Sonoma and Napa counties in the coming months.
ADUs are small, self-contained living units that can be attached or detached to single family homes, within the single family lot. A statewide boom in ADU approvals started up roughly five years ago, when California legislators required local municipalities to relax their regulations on ADUs approvals. Further legislation, particularly in 2020, has made building such units even easier.
Legislators have framed opening up the approval process for ADUs as one part of an effort to take on California’s housing crisis. Though getting ADU plans approved by local governments has become swifter and easier, that’s only one part of the process. The time and financial burden of building such units falls on homeowners who typically have no experience with construction, said John Geary, CEO of Abodu.
That’s a problem because even if a homeowner has sufficient money and interest to build such a structure in their backyard — perhaps because doing so could give them needed rental income, because they’d like to move a family member in there or a variety of other reasons — they might see the time commitment and uncertainty of trying to learn how to navigate the process as too much of a burden.
Abodu designed its business around taking stress out of the process by handling most of it themselves, Geary said. Renée Schomp, director of the Napa Sonoma ADU Center nonprofit, said that similar options are offered by a several other prefab ADU companies.
“Construction is tough. It’s dirty. It’s expensive. It’s confusing. And when the average homeowner is building an ADU, they’re essentially building a home in their backyard,” Geary said. “What we saw is most homeowners aren’t equipped to do that well. It’s a scary endeavor; there’s a lot of opacity in the industry. And so our goal was, how do we make this as simple as buying a car or a product; how do we make it easy as possible for folks?”
Cindy Loughridge and Seth Restaino, owners of the ADU in Sonoma, said that when they bought their home roughly a year ago, there was already an old, run down ADU on the property. The homeowner at the time was working with another company to replace that with a new ADU, which Loughridge said was a selling point for the house.
“The state of the old ADU was almost a deal-breaker,” Restaino recalled. “It was an eyesore, and it had to either come down or be reworked.”
But the company that would’ve built the ADU ended up busy for at least a year, perhaps because of supply chain delays, Loughridge said. Loughridge then discovered Abodu as a replacement option that would get the new ADU installed there relatively quickly. Restaino said the unit — the most expensive model out of three possible Abodu choices, a two-bedroom unit with some upgrades — cost roughly $425,000 in total.
Loughridge said they began talking with Abodu in August 2021 and signed a contract for the ADU in October. Abodu started building the unit at a factory in November, Restaino said, and it took three months for the custom build to be finished. Owing to various permitting and code compliance delays, the unit was installed in late May, and it will be ready to serve as a residence for the bride and groom during a wedding June 25.
“We knew we were the guinea pigs,” Restaino said. “I’m just also a realist about permitting and stuff going to take a little while.”
Restaino said the main point of the ADU for now is that it will serve as a guest house to the two-bedroom main house. He added that it’s possible they might move their parents into the unit when they get older, or it could serve as a long-term rental should they decide to sell the property.
The speed of building such prefab units depends on whether homeowners buy in-production units or wish to design various aspects of the unit. Geary said the organization has installed more than 100 units in California over the past two years, and has several hundred in production behind that.
Schomp said she sees prefab ADUs as one important way to fill California’s extreme need for housing. (Though ADU approvals have been picking up in Napa County and across the state in recent years, the number of total ADU approvals is still minuscule compared to the state’s housing need.)
Schomp added there’s essentially three categories of prefab unit: manufactured, factory built and panelized.
Manufactured housing is certified and regulated on the federal level through the U.S. Department of Housing and Urban Development. That means building requirements are less onerous than factory built, or modular, housing — which is what Abodu builds — because it’s certified at the state level and must be built to state building code standards. As a result, manufactured ADUs tend to be cheaper than factory-built, Schomp said.
Panelized ADUs allow a greater level of customization because only the outer shell of the house is prefabricated, and it’s delivered in flat panels that then have to be assembled.
All prefab ADUs have the advantage of generally being built more quickly than traditionally constructed units and taking a much shorter time to be installed on the property, Schomp said.
“What we do is we manage the ADU process from start to finish, the home is built entirely off site,” Geary said. “So there’s no months and months and months of construction in a homeowner’s backyard. We’re talking about two weeks before delivery, one day of delivery and then about two weeks after delivery, and that’s all the homeowner sees of us in that backyard.”
But, Schomp added, it’s important to recognize that other options — traditional “stick-built” ADUs, junior ADUs that convert areas inside an existing home into housing, multifamily affordable housing — have upsides as well.
And there are also a few limitations to prefab units to consider, she said. Having a flat lot and enough access to the site that a truck can drive in there with the unit, or so a crane can place it, is essentially a requirement.
The ADU center recently launched a “Standard Plans Program” which features a gallery of plans that at least some of 16 Napa and Sonoma county jurisdictions have pre-approved. That allows for a diversity of options for interested buyers, and helps the center pursue a goal of saving homeowners and cities time and money on the design and permitting process for ADUs, Schomp emphasized.
And though organizations like Abodu also work with local governments to have their ADU options essentially be pre-approved to cut down on delivery time and hassle, the ADU Center’s program attempts to solve another potential flaw of prefab ADUs: the relative lack of options most prefab companies offer on their own. Those looking for ADUs can see options from a variety of companies: Abodu, Villa, Connect Homes, Inspired ADUs, Homes for Sonoma and more.
“What I have seen time and time again in the housing space is there’s no single silver bullet solution,” Schomp said. “You cannot say prefab is the answer; it’s one of the tools in the toolkit. And we’re going to be the most successful to meet our housing crisis if we approach with a diversity of housing options.”
Schomp added that she was initially skeptical of prefab ADU companies given that many of them started up, backed by venture capital, after the state’s 2020 housing laws that made local permitting processes for ADUs more uniform came into effect. Those processes still aren’t entirely uniform, she said, which means that in order for the companies to be successful, they need teams of employees that work closely with every jurisdiction they’re building ADUs in.
Schomp said she didn’t anticipate that she’d feel the prefab companies have proven themselves this quickly, but she now feels confident referring people to them. And she believes prefab ADUs are a vital part of solving California’s current housing puzzle.
“I’m pleasantly surprised by how successful these companies have been so far, and I’m seeing homeowners significantly shifting from wanting to do traditional construction to wanting to do prefab,” Schomp said.