California State Housing & Land Use Laws

What’s Allowed — and How I Help You Navigate the Process

California has enacted several state housing laws to expand development opportunities and streamline approvals. These laws can unlock significant potential — but only when applied correctly to a specific parcel, zoning designation, and jurisdiction.

Buchanan Land Use Consulting helps property owners understand what is legally possible and manage the real-world process of working through planning departments, technical requirements, and agency approvals.

SB 9 — Lot Splits, Duplexes, and ADUs

What SB 9 allows

SB 9 applies to qualifying parcels located in single-family residential zones, including some rural residential areas. Eligibility is based on zoning and site conditions — not strictly whether a property is urban.

SB 9 allows:

  • One parcel to be split into two legal lots

  • Up to two primary dwelling units per lot

When combined with California’s ADU laws, a single qualifying parcel may support up to eight dwelling units:

  • 2 lots

  • Up to 2 primary units per lot

  • Up to 2 ADUs per lot (subject to ADU law and site constraints)

What SB 9 does not do

  • It does not guarantee approval

  • It does not override fire, access, slope, utility, or environmental requirements

How I help
I assess SB 9 eligibility, identify realistic development potential, and coordinate the permitting process with planning departments and required licensed professionals.

SB 684 — Streamlined Subdivision for Small Housing Projects

What SB 684 does

SB 684 establishes a ministerial (non-discretionary) subdivision pathway for qualifying small housing developments.

In general, SB 684:

  • Applies primarily to multifamily-zoned parcels

  • Allows subdivision supporting up to 10 residential units

  • Eliminates discretionary hearings when objective standards are met

What it does not do

  • It does not change zoning

  • It does not increase allowable density

  • It does not waive infrastructure or environmental constraints

How I help
I determine whether SB 684 is applicable and manage the technical and agency review process to keep projects moving under ministerial approval.

SB 1123 — Expanded Streamlined Subdivision Framework

What SB 1123 does

SB 1123 expands and clarifies the streamlined subdivision framework created by SB 684.

Unlike SB 684, SB 1123:

  • Requires cities and counties to adopt objective standards

  • Can extend streamlined subdivision eligibility beyond multifamily zoning

  • May apply to vacant single-family residential parcels, depending on local implementation

  • Still limits projects to up to 10 residential units

Key limitation
SB 1123 is not automatic. Its applicability depends heavily on how each jurisdiction has implemented the law through local ordinances.

How I help
I verify local adoption, assess parcel eligibility, and guide project strategy so development aligns with both state law and local requirements.

Quick Comparison: SB 9 vs. SB 684 vs. SB 1123

SB 9

  • Zoning: Single-family residential

  • Lots: 2

  • Units: Up to 8 (when combined with ADU law)

  • Focus: Small-scale residential intensification

SB 684

  • Zoning: Primarily multifamily

  • Lots: Subdivision allowed

  • Units: Up to 10

  • Focus: Ministerial approval for small housing developments

SB 1123

  • Zoning: Multifamily + some vacant single-family parcels (where adopted)

  • Lots: Expanded streamlined subdivision

  • Units: Up to 10

  • Focus: Broadening SB 684 through local implementation

Where These Laws Work Best

These state housing laws tend to work best in jurisdictions that:

  • Have adopted clear SB 9 / SB 684 / SB 1123 procedures

  • Have existing public water and sewer infrastructure

  • Are under pressure to meet state housing element requirements

  • Process ministerial approvals routinely

They are often more challenging in areas with:

  • Very High Fire Hazard Severity Zones

  • Septic-only development constraints

  • Steep slopes or limited road access

  • Unclear or incomplete local implementation standards

Part of my role is identifying where a law is viable — and where another approach makes more sense.

Rural Properties: What to Know

Many state housing laws prioritize urban or semi-urban areas, but rural development is still possible through:

  • ADUs and junior ADUs

  • Agricultural and residential building conversions

  • Traditional subdivisions under the Subdivision Map Act

  • Site-specific or phased permitting strategies

Rural projects succeed when they are structured around real site constraints, not assumptions about streamlining laws.

Frequently Asked Questions

Do these laws guarantee approval?
No. They streamline the process, but projects must still meet objective standards, infrastructure requirements, and site constraints.

Do these laws override local zoning?
No. Zoning and general plan designations still control density and use.

Can septic or well-served parcels qualify?
Sometimes — but infrastructure is often the limiting factor. Each parcel must be evaluated individually.

Are these laws only for cities?
No. SB 9 can apply in unincorporated areas if zoning and conditions allow. SB 684 and SB 1123 depend more heavily on local implementation.

Is one law “better” than the others?
No. The best pathway depends entirely on the parcel, zoning, and jurisdiction.

How Buchanan Land Use Consulting Helps

  • Parcel eligibility and feasibility analysis

  • Zoning and general plan interpretation

  • Strategy for SB 9, SB 684, SB 1123, and alternative pathways

  • Coordination with planning departments and licensed professionals

  • Permit management from concept through approval

Serving property owners throughout California.

Next Step

If you are considering development, subdivision, or additional housing, the most valuable first step is understanding what is realistically possible on your specific property.

👉 Request a Feasibility Review