sb 9, explained
Two homes, or two lots, where there used to be one
Since January 1, 2022, California's SB 9 has let owners of single-family lots add a second home or split the lot in two with a ministerial approval: no public hearing and no discretionary review, as long as the project meets objective standards. On a lot that's split, that can mean up to four homes where there was one. On Silicon Valley land values, the numbers can be significant, and so can the costs.
units on one lot
units after a lot split
smallest new lot
city decision deadline
the two paths
Duplex or lot split
Two units on your lot
Build a second home, or convert or replace the existing one, so the lot holds two units. You keep one parcel. Cities can't use their standards to block two units of at least 800 square feet each.
Urban lot split
Divide one single-family lot into two. Neither new lot can be smaller than 40% of the original or 1,200 square feet (unless your city allows smaller), and each new lot can hold up to two units. You can't split a lot next to one you or an associate already split under SB 9.
the rules that matter
What SB 9 requires
Live there three years
For a lot split, you sign an affidavit that you intend to live in one of the units as your primary home for at least three years after approval.
No short-term rentals
Units created under SB 9 can't be rented for less than 30 days at a time.
Setbacks and parking
Cities can require side and rear setbacks of no more than 4 feet, and no more than one parking space per unit. No parking can be required within a half mile of high-quality transit or a major transit stop.
Places SB 9 doesn't reach
Historic districts and landmarks, very high fire hazard zones without mitigation, flood zones, wetlands and some other protected land are excluded.
Tenant protections
Projects can't demolish or alter rent-controlled or deed-restricted affordable housing, or housing that was occupied by tenants in the last three years.
Faster, firmer decisions
Since January 1, 2025 (SB 450), cities must approve or deny a complete application within 60 days or it's deemed approved, must explain any denial in writing, and can only apply standards that apply across the zone.
property nerd note
Every Silicon Valley city implements SB 9 with its own objective standards: lot coverage, height, privacy and design rules, plus utility and fee requirements. Two lots of the same size on different streets can have very different outcomes. We start every SB 9 conversation with your city's current rules and a quick look at the lot: frontage, slope, trees, easements and utilities.
does it pencil?
SB 9 is a math problem first
Value of the new lot
What a buildable lot sells for in your neighborhood, minus the survey, engineering, map and utility costs to create it.
Cost to build
Construction, design, permits and impact fees for a new home, compared with what that home would sell or rent for when it's done.
Effect on your home
A smaller lot or a second home nearby can change your own home's value. We price your home both ways, so you can see the whole trade.
nextgenagents™
How NextGenAgents™ evaluate an SB 9 lot
Lot screening
Parcel size, frontage, zoning, hazard maps and easements checked before you spend money on design.
Comps for every outcome
Sales of comparable lots, new homes and smaller-lot homes nearby, so each option has a real number attached.
The right team
Introductions to surveyors, civil engineers, architects and builders who have taken SB 9 projects through local cities.
Official sources: California Senate SB 9 resource · California Department of Housing and Community Development · Santa Clara County (unincorporated areas). Cities set their own SB 9 standards; check your city's planning department. General information, not legal advice. Also see Proposition 19.
SB 9, the California Housing Opportunity and More Efficiency (“HOME”) Act, facilitates the process for homeowners to subdivide their current residential lot or build a duplex. State law currently provides for the creation of accessory dwelling units by local ordinance, or, if a local agency has not adopted an ordinance, by ministerial approval, in accordance with specified standards and conditions. SB 9 allows for ministerial approval, without discretionary review or hearings, of duplex residential development on single-family zoned parcels. Let the Boyenga Team provide you with the resources you need to help you take advantage of SB 9 today.
What this bill does: Senate Bill 9 – the California Housing Opportunity and More Efficiency (HOME) Act streamlines the process for a homeowner to create a duplex or subdivide an existing lot. Any new housing created as a result of this bill must meet a specific list of qualifications that protects historic districts, preserves environmental quality and the look of communities, and prevents tenants from being displaced. This legislation will enable homeowners to create intergenerational wealth, and provide access to more rental and ownership options for working families who would otherwise be priced out of neighborhoods.
Do you qualify for SB 9?
SB 9 also allows for qualifying lot splits to be approved ministerially upon meeting the bill requirements. Each parcel may not be smaller than forty (40%) percent of the original parcel size and each parcel must be at least one thousand two hundred (1,200) square feet in size unless permitted by local ordinance. The parcel must also be limited to residential use. Neither the owner of the parcel being subdivided nor any person acting in concert with the owner may have previously subdivided an adjacent parcel using a lot split as provided for in SB 9. The applicant must also provide an affidavit that the applicant intends to use one of the housing units as a principal residence for at least three (3) years from the date of approval. Find out by reaching out to the Boyenga Team.
HOW DO YOU TAKE ADVANTAGE OF SB 9.
MEET WITH THE BOYENGA TEAM
The Boyenga Teams can provide guidance on utilizing SB 9 and whether it will be the highest and best use for your land.
MEET WITH ARCHITECT
Once you chosen an architect and engineer you can put together a proposal to submit to the city of your subdivision.
MEET WITH CONTRACTORS
Once your SB 9 plan is approved you can finalize the build-out. The Boyenga Team recommends that you reach out to us for a consult.
start here
Is your lot an SB 9 opportunity?
Send us your address. We'll check the lot against SB 9 and your city's standards, and show you what each option could be worth.
faq
SB 9: FAQ
What is SB 9?
A California law, in effect since January 1, 2022, that lets owners of single-family lots build a second unit or split the lot in two with a ministerial approval: no public hearing or discretionary review, as long as the project meets objective standards.
How many homes can a lot end up with?
Up to two units on a lot that isn't split. If you split the lot, each of the two new lots can have up to two units, for up to four in total.
How small can the new lots be?
Neither new lot can be smaller than 40% of the original lot or 1,200 square feet, unless your city allows smaller lots.
Does the owner have to live on the property?
For a lot split, yes: you sign an affidavit that you intend to live in one of the units as your primary residence for at least three years after approval.
Can SB 9 units be rented out?
Yes, but not as short-term rentals. Units created under SB 9 can't be rented for terms shorter than 30 days.
How long does city approval take?
Since January 1, 2025, cities must approve or deny a complete SB 9 application within 60 days, or it is deemed approved. Design, engineering and building permits take additional time.
- Los Altos Real Estate Listings
- Los Altos Hills Real Estate Listings
- Los Gatos Real Estate Listings
- Palo Alto Real Estate Listings
- Menlo Park Real Estate Listings
- Portola Valley Real Estate Listings
- Sunnyvale Real Estate Listings
- San Jose Real Estate Listings
- Mountain View Real Estate Listings
- Santa Clara Real Estate Listings
- Redwood CIty Real Estate Listings
- Saratoga Real Estate Listings
Ask the Property Nerds about SB 9
