Is Your Backyard ADU-Ready? What the Newest California Law Says
California just passed new legislation that could make it much easier to build an ADU (Accessory Dwelling Unit)—and homeowners in San Mateo and Santa Clara Counties stand to benefit in a big way. Senate Bill 1211 (SB 1211) became effective January 1, 2025. Additionally, Assembly Bill 2533 (AB 2533) offers protections for homeowners with unpermitted ADUs or Junior ADUs (JADUs) constructed before January 1, 2020. Under this law, local agencies cannot deny a permit solely based on building standard violations unless those violations render the structure “substandard” under health and safety criteria.
As of 2025, cities must process ADU permits within 60 days, HOAs have fewer ways to block them, and zoning restrictions are more relaxed than ever. Some properties that were previously ineligible due to lot size or setbacks may now qualify.
In both counties, this opens the door for homeowners to:
- Add a detached unit for rental income
- Create private space for extended family
- Build a home office, studio, or guest house
- Increase overall property value
With rising demand for flexible living spaces—and growing pressure on housing inventory—this law puts more power in the hands of property owners.
Want to explore what’s possible on your lot?
We’re happy to help you assess feasibility and connect you with experienced local builders.
In the meantime, here are some resources to help you get started:
- San Mateo County ADU Resource Center – Zoning maps, cost estimates, and permit info
- Santa Clara County ADU Guide – County-wide rules and design guidelines
- California HCD ADU Handbook – State-level guidance and law updates
Why Build an ADU?
For many homeowners, an ADU is more than just extra space—it’s a smart investment. Some use it to generate passive rental income, especially in high-demand rental markets like San Mateo and Santa Clara Counties. Others build to create a private space for aging parents, adult children, or long-term guests. And as remote work continues to evolve, detached home offices or creative studios are becoming more common. An ADU can increase your property’s value, flexibility, and long-term livability—without having to leave the neighborhood you love.
We’re proud to share that our team has been nationally recognized by RealTrends, the leading authority on real estate performance in the U.S.
Based on our 2024 sales data, we were named a RealTrends Verified Top Team number of transactions and sales volume, ranking among the top performers at the state and national levels:
- $183.33M in closed sales volume
- 90 homes sold
- #3 team for in San Mateo County.
Thirty years in, and we’re still setting the pace. This recognition reflects the trust of our clients, the strength of our local network, and the commitment our team brings to every transaction. We’re especially grateful to you, our clients, whose continued confidence in our team makes it all possible.
RealSmart is Officially a RealTrends Verified Top Team!
Recognized for both sales volume and performance in 2024.
Looking Ahead: Summer 2025 Predictions
As we move into the summer of 2025, several trends are shaping the single-family home market in these counties:
- San Mateo County: The median sale price for single-family homes at the end of April 2025 was $2,100,000, up from $2,000,000 in April 2024. Inventory levels have slightly increased, with 1.7 months of supply available to buyers. Homes are selling for a median of 105.4% of the original asking price, indicating continued strong demand.
- Santa Clara County: The median sale price as of May 2025 was $2,166,120, a 1.7% increase from the previous month. The average home value in the county is $1,746,723, up 5.8% over the past year. Homes are going ‘pending’ in around 11 days, reflecting a competitive market.
Key Takeaways for Buyers and Sellers
- Buyers: While inventory has seen a slight uptick, competition remains strong. It's crucial to have financing in place and be prepared to act quickly when a desirable property becomes available.
- Sellers: The market continues to favor sellers, with homes selling above list price and in a relatively short timeframe. Proper pricing and presentation remain key to attracting multiple offers.
#3 TEAM BY SALES VOLUME IN SAN MATEO COUNTY
Why This Matters, For YOU
Rankings like these aren’t just accolades, they’re proof. Proof of consistent results in one of the most competitive real estate markets in the country. For our clients, it means you’re working with a team that knows how to price strategically, market effectively, and negotiate with confidence. Whether you’re buying or selling, our experience translates into smoother transactions, stronger outcomes, and a partner you can trust every step of the way.
Key market indicators in San Mateo & Santa Clara Counties
Summer 2025 Market Outlook
Looking Ahead: Summer 2025 Predictions
As we move into the summer of 2025, several trends are shaping the single-family home market in these counties:
- San Mateo County: The median sale price for single-family homes at the end of April 2025 was $2,100,000, up from $2,000,000 in April 2024. Inventory levels have slightly increased, with 1.7 months of supply available to buyers. Homes are selling for a median of 105.4% of the original asking price, indicating continued strong demand.
- Santa Clara County: The median sale price as of May 2025 was $2,166,120, a 1.7% increase from the previous month. The average home value in the county is $1,746,723, up 5.8% over the past year. Homes are going ‘pending’ in around 11 days, reflecting a competitive market.
Key Takeaways for Buyers and Sellers
- Buyers: While inventory has seen a slight uptick, competition remains strong. It's crucial to have financing in place and be prepared to act quickly when a desirable property becomes available.
- Sellers: The market continues to favor sellers, with homes selling above list price and in a relatively short timeframe. Proper pricing and presentation remain key to attracting multiple offers.
