SB 1123 builds on SB 684, which simplified and streamlined approvals for small subdivisions in multifamily zones. The new law extends that same fast-track approval process to vacant lots in single-family zones, a big step forward for small-scale housing.

In short, if a project meets the bill’s objective standards, cities and counties must approve it ministerially within 60 days, meaning no public hearings, no planning commission votes, and no discretionary delays.

Senate Bill 1123 Key Highlights

• Applies to vacant lots in single-family zones up to 1.5 acres
• Allows up to 10 new homes per subdivision
• No minimum street frontage required
• Parcels as small as 1,200 sq ft (depending on local standards)
• Accessory Dwelling Units (ADUs) don’t count toward the 10-unit cap
• Ministerial (fast-track) approval — no public hearings

This change supports “gentle density” — modest increases in housing that fit existing neighborhoods without large-scale redevelopment.

Why This Matters 

There are four very good reasons why this is a big deal and matters:

1. Faster, More Predictable Approvals
   Under SB 1123, qualifying projects can bypass lengthy public reviews and environmental studies, reducing approval timelines from a year or more to just a few months. That means less uncertainty and faster starts for builders and property owners.
   
   
2. Lower Soft Costs
   Every month spent in entitlement adds costs. By shortening timelines and reducing consultant requirements, SB 1123 can lower overall project expenses, making smaller developments financially viable.
   
   
3. New Development Potential
   For the first time, vacant lots in single-family zones can be subdivided into multiple parcels using a simple, objective process. Property owners, small builders, and architects can explore creative new uses for land that previously sat idle.
   
   
4. More Design Flexibility
   The law limits restrictive local rules, such as minimum frontage requirements or oversized setbacks, often making vacant infill lots impractical. That allows more freedom to create compact, efficient site layouts while staying code-compliant.

Who and Why

We see   SB 1123 as more than a new housing law; it’s a practical tool to unlock infill development in existing neighborhoods.

• For architects, it means creative freedom and new design opportunities.
• For developers, it means faster timelines and lower risk.
• For property owners, it means turning vacant or oversized lots into valuable housing opportunities.

Now Is The Time To Prepare! How Greenwood & Moore Can Help

Because SB 1123 took effect in mid-2025, local agencies will soon begin updating ordinances and application procedures. Early site analysis and pre-design planning can help architects, developers, and property owners move quickly once the law is active. Staying ahead of competitors, local agencies and shifting market dynamics.

At Greenwood & Moore, we’re already working with clients to identify potential infill opportunities under SB 1123. Our civil engineering team specializes in:

• Feasibility studies and site evaluations
• Subdivision and infrastructure design
• Drainage and utility coordination
• Entitlement and agency approvals

We can help you understand if your site qualifies, plan efficient layouts that meet SB 1123 standards, and coordinate with jurisdictions for a smooth path to approval.

Whether you’re planning a subdivision, exploring development potential, or helping clients navigate California’s new housing laws, Greenwood & Moore can guide you through every step. Contact us today to discuss your project or schedule a site review.

Visit our blog section for more insights into California’s evolving housing policies and legislation. We’re here to help you make your vision a reality. 

Since 1994, G&M’s goal is to “Make our Clients' Vision a Reality."