New laws are freeing up property owners to think about their land in new ways.

Building permits for Accessory Dwelling Units (ADUs) have skyrocketed in San José over recent years. Lot splits and additional residential units allowed under the California HOMES Act (Senate Bill 9 or SB 9) are also opening up new possibilities for property owners and offering relief to the housing crisis.

Many real estate professionals, home buyers, and property owners are interested in taking advantage of ADUs and SB 9. The Filipino American Real Estate Professional Organization of Silicon Valley hosted an event this month that brought together Santa Clara County realtors with key representatives from the Mayor’s Office and the Department of Planning, Building and Code Enforcement. The goal? To share updates on the City’s housing goals and offer some tips on all things ADUs and SB 9. 

ADUs are booming. Back in 2015, the City of San José issued just 10 building permits for ADUs. Fast forward to 2024, and that number skyrocketed to 488 permits. 

We’re also seeing a trend toward bigger ADUs. In 2015, only 6% of permitted ADUs were over 700 square feet. Today, more than one-third are considered large ADUs. Homeowners clearly see the value in maximizing their space. 

There is also an increased desire to subdivide land to increase value and housing availability. Since San Jose became the first city to allow homeowners to sell their ADUs as separate property in 2024, we have received two ADU condominium map filings. But the real interest seems to be in SB 9 subdivisions and SB 9 units. Nearly 60 subdivisions and over two dozen single-family homes and duplexes have been filed as of March 2025.

Here’s something many homeowners don’t know: If you have a house built legally in San José, you could be eligible to have up to three ADUs on your property. That’s a huge opportunity to create extra living space, accommodate multigenerational living, increase property value, or generate rental income.

Thinking of building an ADU? Start with the City’s ADU Universal Checklist. It’s packed with details on where you can build, how big or tall you can build, and other helpful guidance to set you up for success.

Want to save time and money? The City’s Pre-Approved ADU Program might be just what you need. Over 30 vendors offer city-approved plans. With more than 40 master file options available, there’s likely a design that fits your property—and your vision.

-Post written by Sylvia Do, Division Manager, Planning Division