How SB-9 applies to lots in Alameda County

Posted on
January 20, 2022

Senate Bill (SB) 9 (Atkins), signed into law by Governor Newsom on September 16, 2021, allows property owners within a single-family residential zone to build two units and/ or to subdivide lot into two parcels, for a total of four units. Some details of the legislation are still unclear as some provisions are difficult to interpret and the State is still working on their guidance. The affected State legislation is the additional Government Code Sections 65851.21 and 66411.7, and the amended Government Code Section 66452.6 (Subdivision Map Act).


The bill requires approval of the following development activities:

• Two-unit housing development – Two homes on an eligible single-family residential parcel (whether the proposal adds up to two new housing units or adds one new unit to one existing unit).

• Urban lot split - A one-time subdivision of an existing single-family residential parcel into two parcels. This would allow up to four units(unless a jurisdiction decides to allow additional units).


The bill also outlines how jurisdictions may regulate SB 9projects. The local jurisdictions, including Alameda County, may only apply objective zoning, subdivision, and design standards to these projects, and these standards may not preclude the construction of up to two units of at least 800 square feet each. The County can conduct objective design review but may not have hearings for units that meet the state rules (with limited exceptions). The below is a brief description of SB 9 projects and procedure. The County is following the State legislation given that Alameda have not adopted its own local legislation.


The new SB 9 legislation is limited to R-1 zones (and L combining and PD zones based on R-1), and properties within an urbanized area or urban cluster, as those terms are defined by the U.S. Census Bureau.

SB 9 Implementation within Unincorporated Alameda County Lots Not Being Subdivided Homeowners can use SB 9 to build two new dwelling units on a vacant lot, including up to one ADU per new dwelling unit, for a total of four units. If there is an existing single-family dwelling, then they can add up to one primary dwelling unit plus up to one ADU for each resulting dwelling unit, for a total of four units.

Answer these few questions about your project to find out if you may qualify to get advantage of the benefits California offers to the home owners who want to add more units on their property.

Want to get your permits fast?

Lots Being Subdivided

Homeowners that split a lot will be allowed to build two new dwelling units on each of the two new lots, allowing for a total of four units. If there are existing units on the lot, new homes can be added, for a total of four maximum dwelling units. The homes must conform to local objective rules, as long as those rules allow two 800 sf units on each property.

Check out Scenarios in this article.


The SB 9 legislation details which ways the County may regulate SB 9 proposals. There are some actions that the County must take, some decisions that the County can choose to take, and some topics that the County may not regulate.

The following requirements and limitations apply to all two-unit housing development and urban lot split projects under SB 9:

• Ministerial review – The County must review and process applications for SB 9 two unit housing developments and urban lot splits ministerially without any discretionary / subjective review or CEQA.

• Objective standards – The County may only impose objective zoning, design, and subdivision standards. Any standards shall not physically preclude the construction of two units of less than 800 square feet each, per property.

• 4-foot rear and side setbacks – The County may not impose residential setbacks greater than 4 feet for side and rear property lines.

• Rebuild demolished building with same setback – The County may not impose any setback requirements for a new residence constructed in the same location and to the same dimensions as a legally existing structure that is demolished.

• Zero or one parking space – The County may not require more than one parking space per unit. For properties within one-half mile walking distance of either a high-quality transit corridor or a major transit stop, or within one block of a car share vehicle, no parking spaces may be required.

• Denials for public health and safety exemption – The County may only deny an SB 9 proposal if the Building Official finds that it would have a specific, adverse impact [as defined by the State legislation], upon public health and safety or the physical environment and for which there is no feasible method to satisfactorily mitigate or avoid the specific, adverse impact." Any denials must be based on objective, identified public health and safety standards, policies or conditions that existed when the application was submitted.

• Attached buildings allowed – The County may not reject an application because it proposes adjacent or connected structures provided that the structures meet building code safety standards and are sufficient to allow separate conveyance. SB 9 does not define “sufficient to allow separate conveyance.”


The following additional limitations apply to all urban lot split projects under SB 9:

• Dedications/Improvements – The County may not require dedications of rights-of-way or the construction of offsite improvements.

• Easements – The County may require easements required for the provision of public services and facilities and may require that parcels have access to, provide access to, or adjoin the public right of way.

• No correction of non-conforming conditions- The County may not require correction of an existing non-conforming condition as a condition for ministerial approval.

SB 9 includes a few additional rules, including the County’s ability to require percolation tests for onsite wastewater treatment in two-unit development projects and the lack of a public hearing requirement for coastal development permit applications. This latter does not apply to the County.

Find out if your project qualifies for streamline permitting under Senate Bill 9 (SB9) to get the permits fast

SB-9 Applicability

SB 9 applies in all Urban Areas, as defined by the US Census Bureau, except for the following:

• Environmental Sensitivity/Environmental Hazards -Properties designated as:

o Prime farmland or farmland of statewide importance

o Wetlands

o Within a very high fire hazard severity zone (with exceptions)

o A hazardous waste site (with exceptions)

o Within a delineated earthquake fault zone (with exceptions)

o Within a flood zone (with exceptions)

o Identified for conservation or under conservation easement

o Habitat for protected species

• Ellis Act Properties where the Ellis Act was used to evict tenants at any time in the last 15 years.

• Historic Properties - Properties located in a state or local historic district, or properties designated historic landmarks.


Other restrictions:

• Deed restricted affordable housing and rental housing – SB9 projects may not demolish housing that is subject to a recorded covenant, ordinance, or law that restricts rents to levels affordable to persons and families of moderate, low, or very low income.

Nor is it allowed for housing that is subject to any form of rent or price control through a public entity’s valid exercise of its police power. Demolition is also not permitted for housing that has been occupied by a tenant in the last three years.

• No short-term rentals – Rental terms less than 30 days are not allowed.

• Limits on demolition - Projects may not demolish more than25 percent of existing exterior structural walls unless the property has not been occupied by a tenant for 3 years.

Urban Lot Split-Specific Rules

• One use - Only one lot split allowed under SB 9, but note further splits may be possible under regular subdivision procedures.

• Residential only - The uses on the resulting lots are limited to residential uses only.

• Approximately equal size - Each new parcel must be" approximately equal" in lot area provided that one parcel shall not be smaller than 40percent the size of the original parcel.

• Minimum 1,200 sf parcel - No parcel shall be less than1,200 square feet. (The County may, by ordinance, adopt a smaller minimum lot size subject to ministerial approval.)

• Intention to occupy required only of Subdivisions – The subdivider must sign an affidavit stating, they intend to occupy one of the units for a minimum of three years. The County cannot impose additional owner occupancy standards. Community land trusts and qualified nonprofits are exempted from this requirement.

• Limits on adjacent urban lot splits - Neither the subdivider nor any person "acting in concert" with the subdivider has previously subdivided an adjacent parcel using an urban lot split. SB 9 does not define what "acting in concert" means or how it would be proven.



SB 9 projects are ministerial review. No public hearing (not even at the MACs).

• SB 9 residential development applications: Same over-the-counter Building Permit submittal process for all non-SDR residential development applications.

• SB 9 lot split applications: Same Subdivision application requirements as a Tentative Parcel Map Subdivision application. Same fee deposits, for now. Same fee deposits for PWA as well.


Since these are ministerial permits, these are not projects under CEQA and therefore CEQA does not apply.


• SB 9 residential development applications: No Planning Department review fees. Yes Park Dedication Fees for new dwelling units, and for ADUs over 750 sq. ft.

• SB 9 lot split applications: Same Subdivision application requirements as a Tentative Parcel Map Subdivision application. Same fee deposits, for now. Same fee deposits for PWA as well. Additional fees: Park Dedication Fees for new dwelling units, and for

ADUs over 750 sq. ft.

Posted on
California SB-9

Ready to find out the Untapped Potential for your address?

How it works