1.  Purpose and Policy Foundation

SB 684 is part of the state’s continued “Starter Home Revitalization Act” framework, a legislative movement that seeks to facilitate the creation of small, entry-level homes for sale on underused urban lots.  As SB-684 implementation memos emphasize, the Law requires ministerial approval to expedite subdivisions that meet clear, objective criteria.

The Legislature’s reasoning is straightforward: California has produced only ~45% of the homes needed over the last decade, and for-sale starter homes are particularly undersupplied.  SB-684 directly addresses this shortage by enabling small-lot ownership Housing, where local processes have historically posed barriers.

2.  What SB-684 Does

A. Requires Ministerial Approval

Local agencies must approve qualifying subdivision maps and corresponding small Housing projects without discretionary review or public hearings.
This includes:

• Parcel maps
• Tentative and final maps
• Building permits for units within an approved SB 684 subdivision

The approval must occur within 60 days of a complete application.  [

Because the process is ministerial, it is:

• CEQA‑exempt (no environmental review)
• Not subject to public appeal
• Limited to objective local standards only

3.  Eligibility Criteria for SB-684 Projects

Eligibility is defined in Government Code § 66499.41 (added by SB 684).

All the following conditions must be met.

A. Lot Requirements

The parcel being subdivided must:

• Be zoned for multifamily residential use
• Be no larger than 5 acres
• Be a legal parcel located:
• Within an incorporated city, or
• Within an “urbanized area” or “urban cluster” in counties >600,000 population
• Be at least 75% surrounded by “urban uses” (residential, commercial, institutional, transit, or retail uses)

B. Subdivision and Unit Requirements

• 10 or fewer parcels
• 10 or fewer residential units, excluding ADUs/JADUs
• Minimum lot sizes:
• 600 sq. ft. in multifamily zones
• (SB 1123 will extend this to 1,200 sq. ft. in single-family zones as of 2025)
• Project must be served by public water and municipal sewer systems.

C. Density Requirements

If the parcel is listed in the local Housing Element:

• The project must meet or exceed the projected number of units in the site inventory.

If not listed:

• The project must meet at least the maximum allowable density under zoning.
• Some cities apply a 66% maximum-density standard, depending on context (e.g., Berkeley analysis). 

D. Unit Size Limit

• Units may not exceed an average of 1,750 net habitable sq. ft. per dwelling. 

E. Prohibitions

A site is not eligible if:

• It was created through an SB 9 lot split
• The project would demolish or alter protected units
• Including rent-controlled, affordable, or recently occupied units
• It is located on environmentally sensitive land as defined in statute. 

4.  What Local Governments May — and May Not — Impose

SB 684 limits local regulatory authority to objective standards, which should reassure city officials that processes are fair and transparent, fostering trust in the legislation.  Clarify how these standards interact with existing zoning laws to prevent conflicts and ensure smooth implementation.

Allowed (Objective) Standards

Examples include:

• Setbacks:
• 4 ft side/rear setbacks from original lot line
• No interior setbacks between new lots
• Parking:
• Max 1 space per unit
• 0 spaces allowed if the project is within ½ mile of major transit
• Height limits must not be lower than the base zoning
• FAR minimums of:
• 1.0 for projects of 3–7 units
• 1.25 for 8–10 units
  (local agencies must waive standards that physically preclude achieving the minimum statutory density)

Not Allowed

Cities cannot:

• Require CEQA analysis
• Impose discretionary hearings
• Apply subjective design review
• Require creation of HOAs unless the project otherwise necessitates one (SB 684 exempts some from HOA formation requirements)

5.  Timeline Requirements

Local agencies must complete the ministerial review within:

• 60 days of filing a completed application for:
• Parcel maps
• Tentative/final maps

Failure to act constitutes constructive approval under ministerial standards.

SB 684 supports multiple ownership types, including fee-simple small-lot homes, CIDs, co-ops, and community land trusts, making owners and advocates feel recognized and supported.  Highlight how these options open new pathways for small-scale development and community-led Housing initiatives.

SB 684 is designed for sale Housing and supports multiple ownership types:

• Fee‑simple small‑lot homes
• Common interest developments (CIDs)
• Co-ops
• Community land trusts

• The Law intentionally avoids restricting projects to conventional single-family subdivisions.

7.  Interaction with SB-1123 (2024)

While SB 684 initially applies only to multifamily‑zoned lots, SB 1123 (effective 1 July 2025) will expand the program to:

• Vacant single-family zoned lots up to 1.5 acres
• Permit similar 10-unit ministerial approvals

SB 1123 is therefore best understood as Phase 2 of SB 684’s policy architecture.

8.  Practical Implications

SB 684 has substantial real-world implications for Housing providers, including:

For Developers

• Dramatic reduction in entitlement timeline
• No CEQA exposure
• Predictable approval outcomes
• Opportunities for small, infill ownership Housing

For Property Owners

• Ability to legally subdivide and develop small lots that were previously uneconomic
• New pathways for adding “starter homes” to the market

For Cities

• Reduced discretion but clearer processes
• Must rely solely on objective standards
• Must adjust local ordinances to comply (most cities are issuing implementation memos)

9.  Summary

SB 684 requires California cities to approve qualifying subdivisions of 10 or fewer parcels—and their associated Housing projects—through a fast, CEQA-exempt ministerial process, as long as they meet clear objective criteria.  The Law applies to multifamily‑zoned lots under 5 acres, limits units to 1,750 sq. ft. on average, mandates up to 10 homes per project, and forces cities to issue approvals within 60 days.

This single reform has the potential to significantly expand the supply of entry-level, for-sale Housing on infill urban lots.

Then comes SB-1123 to expand SB-689

How SB 1123 Expands and Extends SB 684

SB 684 (effective 1 July 2024) created a statewide, ministerial, CEQA-exempt process for small‑lot subdivisions and Housing projects of 10 or fewer units on multifamily‑zoned lots under 5 acres.  SB 1123 (effective 1 July 2025) builds directly on SB 684’s framework and widens the range of eligible properties, unlocking even more sites for small ownership Housing.

Below is a structured breakdown of the expansion.

1.  SB 1123 Opens the Door to Single-Family Zoned Lots

SB 684 (Baseline):

• Applies only to multifamily‑zoned parcels under 5 acres. 

SB 1123 Expansion:

• Expands eligibility to vacant single-family zoning districts.
• Allows construction of up to 10 homes on vacant single-family lots ≤ 1.5 acres starting 1 July 2025. 

Why It Matters

This is the biggest change.  SB 684 was limited to MF zones; SB 1123 now permits small-lot homes for sale in areas once restricted to one home per lot, dramatically increasing the number of developable sites.

2.  SB 1123 Extends the Starter Home Revitalization Framework

Both bills operate under the “Starter Home Revitalization Act” concept—small ownership units on infill parcels—, but SB 1123 is described as the next phase:

• SB 684 applies to multifamily sites.
• SB 1123 expands the same ministerial, CEQA‑exempt system across additional zoning categories, especially single-family zones—noted as a major broadening of SB 684’s reach. 

3.  SB 1123 Increases Geographic and Parcel-Type Eligibility

SB 684 Requirements:

• Parcel must be a legal lot
• ≤ 5 acres
• Located in an incorporated city or an “urbanized area/urban cluster.”
• Substantially surrounded (≥ 75%) by urban uses

SB 1123:

• Applies the same standards but widens the universe of eligible parcels by taking the program into single-family zoning on lots ≤ 1.5 acres.
• Ensures small subdivisions are permitted where they were previously prohibited by zoning.

This opens a large number of previously off-limits parcels statewide.

4.  SB 1123 Keeps the Same Streamlined Benefits—But for More Sites

Both laws guarantee:

• Ministerial approval
• CEQA exemption
• No public hearing
• Objective standards only
• 60-day approval clock

SB 1123 applies these same benefits to a vastly larger pool of lots—particularly in established lower-density neighborhoods where California has tremendous underutilized land capacity.

From the City of Berkeley’s SB 684/SB 1123 implementation materials:

SB 1123 “expands eligibility to vacant single-family lots less than 1.5 acres,” enabling the same small‑lot subdivision streamlining created by SB 684. 

5.  SB 1123 Expands the State’s Goal of Unlocking “Starter Homes.”

Both SB 684 and SB 1123 are explicitly intended to increase production of small, naturally affordable, for-sale homes.

SB 684 focuses on multifamily zones, but SB 1123:

• Legalizes homeownership-scale development in single-family areas
• Accelerates development in zones where most of California’s urban land is located
• Opens the possibility of 6–10 fee‑simple homes or small HOAs/condos on parcels that previously allowed only one house

This expansion directly aligns with the policy rationale that small infill lots statewide are chronically underutilized and ideal for starter Housing.  SB 1123 extends this revival of missing-middle homeownership opportunities beyond multifamily zones into conventional neighborhoods.

6.  SB 1123 Is a Natural Second Phase of SB 684

SB 684 is referred to as the first step: a ministerial small‑lot subdivision Law for infill multifamily sites.

SB 1123 is described in the legislative analysis as:

• An expansion of the SB 684 program,
• Making its benefits available in vacant single-family zones,
• And further “legalizing construction of up to 10 homes” in areas once restricted to one unit per lot. 

Thus, SB 1123 does not replace SB 684; it expands the platform.

7.  Summary: How SB 1123 Expands SB 684

SB 1123 EXPANDS SB 684 BY:

• Adding single-family zoning eligibility (vacant lots ≤ 1.5 acres)
• Increasing the number and type of parcels that qualify
• Applying SB 684’s ministerial, CEQA-exempt process to new areas
• Bringing small‑lot ownership Housing to low-density neighborhoods
• Allowing the same 10-unit small-lot subdivision model beyond multifamily zones

In short:

SB 684 opened the door.  SB 1123 widens it.

SB 684 created a streamlined approval path for small ownership subdivisions on multifamily-zoned land; SB 1123 extends that pathway into single-family zones, significantly enlarging California’s capacity for small, for-sale infill Housing.