In 2018, the State of California loosened the regulations around accessory dwelling unit—or ADU—development for single-family homeowners as a way to increase density and bring more housing supply to the market. In the last two years, ADU development has increased dramatically as homeowners better understand how they can take advantage of the opportunity.

"This is getting a lot of press because of the legislation," Paul Dashevky, a partner at GreatBuildz, tells GlobeSt.com. "The state legislation has eased up restrictions to create more density, and that has opened up a lot of possibilities. For all intents and purposes, an ADU is a second units. However, it isn't categorized as a second unit, but that is essentially what you will have. It is a property with two homes on it. There are a lot of creative ways for people to use them."

Homeowners are doing everything from adding income-producing units—which was the goal of the legislation—to fitness facilities, home offices and in-law suites. These units are also ideal senior housing units for the homeowner's family. As a result of the uses, the permit requests are increasing rapidly. "In 2016, there were only 300 permitted ADUs," says Dashevky. "In 2017, there were 3,000 permitted, and now there are more than 13,000 permitted. The numbers are definitely skyrocketing."