• Golden State ADUs
• Comment 0

Senate Bill 684 Explained: A New Opportunity for Lot Splits and ADU Development in California

California continues to face a severe housing shortage, and state leaders have introduced various Senate Bill reforms to open new paths for housing development. One of the most significant recent laws is Senate Bill 684, often referred to as SB 684, which reshapes the way small scale subdivisions and housing units can be built on specific types of property. The legislation became operative in 2024 and introduces a streamlined approval process for certain housing development projects. It creates meaningful opportunities for homeowners to expand with fewer parcels, new residential units, and accessory dwelling units, often without the traditional delays associated with discretionary review.

For homeowners in Sacramento, Roseville, Elk Grove, Folsom, Citrus Heights, and surrounding Northern California areas, the new rules allow a wider range of development projects on many qualifying sites. When paired with the design and build expertise of Golden State ADUs, Senate Bill 684 becomes a powerful tool for increasing property value and expanding housing choices for rental income or multigenerational living.

What Is Senate Bill 684, A Quick Overview

Senate Bill 684 is part of California’s ongoing efforts to increase the supply of qualified housing developments by reducing unnecessary barriers in the planning and zoning law framework. The law requires a local agency to process certain subdivision maps and housing development projects ministerially, meaning without discretionary review. This includes a parcel map, a tentative and final map, and housing development projects involving 10 or fewer residential units. The goal is to simplify the process and bring more predictability for homeowners interested in planning a proposed subdivision or adding accessory dwelling units on newly created parcels.

The law only applies to specific types of lots. A qualifying lot proposed for subdivision must be zoned for multifamily residential development, must not exceed five acres, must be a legal parcel located in an urban area, and must be substantially surrounded by qualified urban uses. When a proposed housing development meets the criteria, the local agency must rely on objective standards and may not impose unreasonable delays or hearings.

Senate Bill 684 also aligns with the Starter Home Revitalization Act, which focused on increasing smaller, more attainable housing options. Together, these statutory provisions establish procedures for infill development that support California’s planning and zoning law reforms. Importantly, SB 684 is recognized as a state mandated local program, which means local agencies are required to comply with its provisions, ensuring uniformity in the local agency review process across jurisdictions.

Key Goals of the Bill

The law was written to support several priorities:

• Promote small scale homeownership opportunities and expand access to attainable housing through lot splits and fewer residential units built on new legal parcels.
• Reduce the impact of discretionary review and create predictable timelines for any proposed housing development.
• Support infill growth near qualified urban areas by offering simplified ways to complete a parcel map or tentative and final map that complies with objective standards.
• Allow the ministerial approval process to replace outdated barriers that slowed down development projects in the past.
• Encourage property owners to add accessory dwelling units, junior accessory dwelling unit options, or smaller multifamily structures.

By simplifying approvals and ensuring ministerial approval, the state expects more qualified housing developments to move forward without the long delays that come with environmental impact report reviews and traditional hearings.

How SB 684 Works, Key Provisions and Requirements

Eligibility Criteria

A property must satisfy several requirements before it qualifies under SB 684. Some of the most important criteria include:

• The lot proposed for a subdivision must be zoned for multifamily residential development and must be substantially surrounded by qualified urban uses.
• The property must be five acres or smaller.
• The subdivision must create 10 or fewer parcels, and the housing development project consisting of 10 or fewer residential units must meet local objective standards.
• The newly created parcels must meet minimum size standards, often as low as 600 square feet depending on zoning and local ordinance guidelines.
• The proposed housing development must meet or exceed the maximum allowable residential density for the site, as established in the adopted housing element.

Beginning July 1, 2025, new amendments will expand eligibility to certain vacant lots within a single family residential zone, provided those sites meet specific standards outlined in related legislation.

What the Law Allows

When the proposed housing development meets the statutory requirements, homeowners gain several key benefits:

• A local agency must issue ministerial approval for the subdivision through a parcel map or a tentative and final map pursuant to the law.
• A building permit for the residential units must be issued ministerially once the application is complete.
• The law shields qualifying projects from broad California Environmental Quality Act obligations because CEQA does not apply to ministerial approvals.
• If a local agency denies a complete application or fails to act within the mandatory timeline, the application is considered deemed approved.

These rules create a more predictable and accessible pathway for homeowners to expand with fewer parcels, proposed housing units, and added flexibility for ADUs.

Local Government Limitations

While the law offers benefits, it also imposes important limits on local government authority. A local agency pursuant to SB 684 may not:

• Require discretionary review or public hearings for a qualifying proposed housing development.
• Apply subjective or arbitrary standards that prevent the construction of residential units at the maximum allowable residential density.
• Delay the process for reasons unrelated to zoning or local inclusionary housing ordinances.

However, an applicable local government may still enforce objective zoning law requirements, subdivision map act requirements, and design standards. These standards cannot prevent the construction of 10 or fewer residential units when the law applies.

If the local agency receives a complete application and does not act within 60 days, the law requires that the project be deemed approved under the ministerial approval rules.

Why Senate Bill 684 Matters to California Homeowners

Unlocking Hidden Property Value

Because existing law often made small scale development difficult, SB 684 introduces a more flexible environment. A homeowner with a qualifying lot proposed for a subdivision can create newly created parcels and develop housing units with considerably fewer obstacles. This opens the door to rental income opportunities, space for family members, or long term property value increases.

Lot Splits and Accessory Dwelling Units as a Combined Strategy

One of the most effective strategies is to combine a subdivision with one or more accessory dwelling units. For example:

• A homeowner completes a parcel map or tentative and final map under the ministerial approval process, creating two or more newly created parcels.
• Each new parcel becomes eligible for a primary home or proposed housing units, plus accessory dwelling units or junior accessory dwelling unit options where allowed.
• This allows the homeowner to create multiple income producing units or flexible multigenerational spaces while staying within the limit of 10 or fewer residential units.

This approach is especially powerful because the subdivision map act requires certain conditions, but SB 684 streamlines those requirements when the statutory conditions are met.

Benefits for Multigenerational Living and Investors

Families seeking multigenerational solutions can now use separate parcels with shared access, ensuring privacy while staying together. Investors can develop smaller development projects, often with fewer risks compared to large multifamily buildings.

Because SB 684 supports proposed subdivision plans that comply with objective standards, many of the delays tied to discretionary review or CEQA do not apply.

SB 684 vs SB 9, Understanding the Difference

Both SB 684 and SB 9 are Senate Bill reforms designed to increase housing supply, but they apply to different settings.

• SB 9 focuses on single family residential properties and allows up to two units on a single parcel with the possibility of adding ADUs.
• SB 684 applies to lots zoned for multifamily residential development and supports a housing development project pursuant to the law with up to 10 or fewer residential units and up to 10 new parcels.

This distinction means SB 684 can support more robust small scale development projects in urban areas. Homeowners unsure which law applies can rely on Golden State ADUs for accurate eligibility reviews.

When the Law Applies, Timeline and Requirements

Key Dates

• SB 684 became operative on July 1, 2024.
• The expansion for single family residential zones becomes effective July 1, 2025.

Remaining Requirements

Even though the law creates streamlined approval processes, property owners must still complete:

• A parcel map or tentative and final map that complies with subdivision map act standards.
• A building permit application that meets objective standards.
• Requirements related to utilities, frontage, and site access.
• Compliance with any local inclusionary housing ordinances in the applicable local government.

The postentitlement phase permit applications process becomes simpler once the subdivision is approved, but every standard must still be met.

How Golden State ADUs Helps Homeowners Use SB 684

Golden State ADUs supports homeowners with detailed zoning analysis and planning services. The team reviews the housing element, zoning designation, parcel history, and subdivision options to determine eligibility. They also manage the mapping process for a parcel map or tentative map approval, coordinate with the local agency, and prepare building permit submissions.

Full Service Design and Build Support

• SB 684 compliant subdivision planning
• Permitting coordination with local governments related to objective standards
• ADU and residential unit design on each new parcel
• Navigation of the ministerial approval process depending on project type
• Compliance with the health and safety code, planning and zoning law, and subdivision map act rules

By handling the full process, Golden State ADUs ensures that homeowners can focus on the benefits rather than the paperwork.

Is Your Property Eligible Under SB 684

Homeowners interested in learning whether their site qualifies can begin by gathering the property address and APN. Golden State ADUs will evaluate whether the site is a legal parcel located within qualifying urban boundaries, whether the lot proposed meets the acreage limits, whether the zoning complies, and whether the project fits the objective standards outlined in the law.

If the site qualifies, the team will create a strategy for subdivision, ADU construction, and building permit steps. Acting early is valuable because other above described provisions operative in the future may affect available options.

Frequently Asked Questions (FAQs) about Senate Bill 684

What types of properties qualify for Senate Bill 684 subdivision and housing development projects?

SB 684 applies to lots zoned for multifamily residential development that are five acres or smaller, substantially surrounded by qualified urban uses, and located within an incorporated city or urbanized area. Beginning July 1, 2025, certain vacant lots in single-family residential zones may also qualify under related amendments.

How many residential units and parcels can be created under SB 684?

The law allows for subdivisions and housing development projects that result in 10 or fewer parcels and 10 or fewer residential units, including accessory dwelling units, subject to local objective standards.

Does SB 684 require discretionary review or public hearings for qualifying projects?

No. SB 684 mandates a ministerial approval process, meaning local agencies must approve qualifying projects without discretionary review, public hearings, or delays unrelated to objective zoning or inclusionary housing ordinances.

Can local agencies impose design or zoning standards on SB 684 projects?

Local agencies may apply objective zoning, subdivision, and design standards that do not physically preclude development at the maximum allowable residential density. However, subjective or arbitrary standards and certain requirements, such as setbacks or parking standards inconsistent with the law, are prohibited.

What happens if a local agency does not act on an SB 684 application within the required timeline?

If the local agency does not approve or deny a completed application within 60 days of receipt, the application is deemed approved, allowing the project to proceed under the ministerial approval rules.

Final Thoughts

Senate Bill 684 opens new possibilities for homeowners interested in creating proposed housing units, adding accessory dwelling units, or building small scale multifamily structures. The law reduces barriers that once discouraged many families from considering a proposed subdivision or mixed use project. With a clearer path to tentative and final map approval and final map pursuant to objective standards, property owners now have more flexibility.

Golden State ADUs stands ready to support homeowners through every step, from planning and subdivision to construction and completion. If you believe your lot may qualify under SB 684, now is the time to review your options and plan ahead.