Understanding SB 9 From A Silicon Valley Real Estate Expert

Payne Sharpley January 3, 2026

SB 9, also known as the California Housing Opportunity and More Efficiency (HOME) Act, changed the rules for homeowners in Silicon Valley by allowing most single-family lots to be split in two and up to two housing units to be built on each parcel. This allows for up to four separate homes where only one was permitted before. The law’s goal is to provide more housing options in high-demand areas without requiring major new construction or subsidies, but it also comes with clear rules, limitations, and important considerations for anyone looking to take advantage of these new possibilities.

What Is SB 9?

SB 9 requires cities to allow homeowners to either split a qualifying single-family lot into two and/or build an additional home on each of those lots, effectively legalizing duplexes and lot splits in most neighborhoods. Owner-occupied requirements, minimum lot sizes, and local planning criteria still apply, but most local governments must issue approvals as long as an application meets the state’s requirements. Homeowners must sign an affidavit to live in one of the new units for a minimum of three years, which aims to prevent investor speculation.

How SB 9 Impacts Silicon Valley Real Estate

SB 9 unlocks important opportunities for homeowners in Silicon Valley. Instead of being restricted to one home per lot, qualifying owners can now add more housing, potentially increasing property value, creating new rental income, and enabling multigenerational living on a single plot. This law gives homeowners the tools to make the most of their property, while also helping to address California’s urgent housing shortage.

The approval process is now much faster and easier for qualified projects, and property owners no longer need to navigate layers of discretionary city review. Local governments must review SB 9 applications within 60 days and can only deny them for specific health or safety reasons. For many, SB 9 can turn their home into a foundation for long-term financial stability, family support, or smart investment.

Understanding how to take advantage of SB 9’s benefits can be complex, but you don’t have to figure it out alone. Payne Sharpley guides clients through every step of the process, helping you assess your property’s potential, navigate the requirements, and realize your goals with confidence. Reach out to Payne for local expertise and hands-on support to make the most of this exciting new option.

Key Requirements and Limitations

Each split parcel must be at least 40% of the original property’s size, with a minimum of 1,200 square feet per lot.
Homeowners are required to sign an affidavit agreeing to live in one of the units as their primary residence for at least three years.
Local governments can only deny applications for clear and objective reasons such as health or safety concerns.
SB 9 does not override rules for historic preservation or certain environmental protections.
No short-term rentals: SB 9 units must be rented for at least 30 days if not owner-occupied.

Opportunities and Challenges

Homeowners may benefit from increased property values and additional rental income. SB 9 may help families accommodate multiple generations or create new ways to afford living in Silicon Valley. However, challenges include construction costs, financing, and strict eligibility rules. The need for owner occupancy and minimum lot size limit how many owners can actually use SB 9’s provisions. While there is potential to increase homeownership and housing access, full neighborhood transformations are unlikely in the near future.

FAQ

Can any homeowner in Silicon Valley use SB 9?
Not all homes qualify. The property must be in a single-family zone, not in a historic or protected area, and must meet local requirements and lot size minimums.

Do I have to live on the lot if I split it or add units?
Yes, homeowners must commit to occupying one of the units as their primary residence for three years after getting approval.

How many homes can I build using SB 9?
You can build up to two units on each resulting lot, for a total maximum of four homes on what was originally a single-family plot.

Can the city say no to my application?
Local governments can only deny SB 9 requests for specific, objective reasons, like health or safety concerns or if the lot is in an exempted area, such as a historic district.

Will SB 9 reduce my property value?
In most cases, the law is intended to increase flexibility and, potentially, home value. However, every property is different, and there are costs and considerations to weigh, including construction expenses and neighborhood context.

Connect with Payne Sharpley

If you’re interested in understanding your home’s SB 9 potential or want expert advice on buying, selling, or developing property in Silicon Valley, reach out to Payne Sharpley, your trusted Silicon Valley real estate agent. Payne offers personalized guidance on SB 9, and helps you evaluate your property’s options. Contact Payne today to schedule a consultation and discover what’s possible for your home.

"This blog is for informational purposes only and should not be considered legal, financial, or real estate advice. Readers should consult with a qualified real estate professional or attorney before making any real estate decisions. The author and publisher assume no responsibility for errors, omissions, or changes in law or policy."