California Senate Bill 9 (SB9) was signed into law by Governor Newsom on September 16, 2021, and took effect on January 1, 2022. Subject to certain requirements, SB9 allows ministerial (staff level building permit) approval of a proposed housing development containing no more than 2 residential units (e.g., one duplex or two (2) detached single-family homes)) in single-family residential zones OR a subdivision of one (1)  single-family residential lot into two (2) lots. SB 9 Infographic

In most circumstances, SB 9 will result in the potential creation of four dwelling units from an existing single-family parcel, generally in the four (simplified) scenarios depicted, below. In comparison, a single-family property is currently permitted three units, inclusive of a single-family dwelling, an ADU, and a JADU.


Projects for a Two-Unit Development and/or an Urban Lot Split must meet all the criteria on the respective Senate Bill 9 (SB 9) Eligibility Checklist to qualify for ministerial review. A project that includes a proposal for a Two-Unit Development and an Urban Lot Split must complete both checklists.

IMPORTANT NOTE: SB 9 only applies to single-family residential zones.


If you determine your project is eligible, you may apply for the SB 9 Two-Unit Development, and/or the Urban Lot Split using the Universal Planning Application. In addition, the following forms are also required for a complete application.

Additional Information on Subdivisions: You will need to hire a Licensed Surveyor or Engineer to prepare a tentative (parcel) map and illustrate compliance with the Subdivision Map Act and the Milpitas City Code: Chapter 1 – Subdivisions 

Tentative Map Submittal Requirements:
See the Universal Planning Application for Submittal Details on tentative parcel maps.

Note: A maximum of two units of any kind (primary dwelling, ADU, or Junior ADU) on each of the two resulting lots from an urban lot split are allowed. An ADU / Junior ADU is not permitted when the lot is split, and two primary units are developed on each lot.


1. Completeness & Eligibility Review. The City will issue a determination of completeness and eligibility within 30 days of receipt of an application.

2. Action on the Application. City staff will issue an approval or denial on the application within 60 days of the completeness determination.


Following project approval, permits including Building Permits and Encroachment Permits are applied for and reviewed.


On December 14, 2021, the City Council adopted an Urgency Ordinance to implement SB 9 before the law went into effect on January 1, 2022.  The Urgency Ordinance and associated staff report may be viewed at the links below.

AR – SB 9 Urgency Ord_Milpitas – 12.08.2021 FINAL.pdf 

SB 9 Urgency Ordinance_Milpitas.Draft_12.08.21 FINAL.pdf 

Exhibit A_SB9 Code Amendments_Redline_12.08.2021 FINAL.pdf 

Final PC Reso SB 9 Urgency Ord Milpitas_DocuSigned by Chair.pdf 


What is SB9?

Senate Bill 9 (SB 9) is a new law enacted by the State of California that increases the allowed density on certain single-family lots. SB 9 adds two new sections to the Government Code (§§ 65852.21 and 66411.7) that make it easier to add a second single-family residence or split an existing lot (urban lot-split) in areas which meet the requirements.

Can I use SB9 to split my parcel?

SB 9 “urban lot-splits” are subject to the same restrictions set forth in the preceding FAQ. (See Government Code § 66411.7.) If a parcel has some of these restrictions, please meet with a planner to determine the applicability of SB 9. SB 9 requires that each resulting lot be at least 1,200 square feet. A parcel may only be subdivided using SB 9 one time (i.e., the 2 parcels resulting from the urban lot-split may not be further subdivided pursuant to SB 9).

Can I rent out the units created by and SB9 project?

Applicants for an urban lot-split under SB 9 must sign and record a deed restriction that they will use one of the units as their primary residence for a minimum of three years. Otherwise, units may be rented, but for terms of at least 30 days (no Short-Term Rentals).

Does SB9 apply to homeowners' associations (HOAs)?

SB 9 does not address rules or restrictions implemented and adopted by homeowners’ associations or included in CC&Rs (covenants, conditions, and restrictions). The City does not enforce private CC&Rs.

How does the Permit Streamlining ACT apply if these are ministerial actions?

SB 8, also effective January 1, 2022, extends the requirements of the Permit Streamlining Act to housing projects of one unit or more that require no discretionary approvals. As a consequence, SB 9 projects are subject to the Permit Streamlining Act’s requirements for completeness determinations (within 30 days of submittal) and approval deadlines (within 60 days of determining that the project is exempt from CEQA).

Can I partially or completely demolish and existing dwelling for by SB9 project?

You may not demolish the dwelling if it is rent-controlled, subject to affordable housing restrictions, or a renter was evicted from the dwelling in the past 15 years. You may not demolish more than 25% of an existing dwelling’s exterior walls if the dwelling has been a rental property in the past three years.

SB9 & Accessory Dwelling Unit (ADU)

One (1) attached or detached ADU may be permitted on a single-family lot that has not been subdivided pursuant to SB9. An ADU is not permitted on an SB9 subdivided lot. Additional information on requirements for ADUs can be found in Milpitas City Code (MMC) Section XI-10-13.08

In addition to complying with the design and development standards outlined in the SB9 2-Unit Objective Design Standards outlined in the urgency ordinance, and pursuant to (MMC) Section XI-10-13.08 (Streamlined Accessory Dwelling Units), the maximum floor area allowed for the Accessory Dwelling Unit shall be eight hundred (800) square feet, the side-and-rear-yard setbacks are at least four feet, and the maximum height shall be sixteen (16) feet.

SB9 & Junior ADUs

One (1) Junior ADU may be permitted on a single-family lot that has not been subdivided pursuant to SB9. A Junior ADU is not permitted on an SB9 subdivided lot. Additional information on requirements for Junior ADUs can be found in (MMC) Section XI-10-13.08

In addition to complying with the design and development standards outlined in the SB9 2-Unit Objective Design outlined in the urgency ordinance, and pursuant to (MMC) Section XI-10-13.08 (Junior ADU standards),  the JADU unit must be constructed within the existing walls of an existing or proposed residential dwelling (i.e., one detached single-family home or one of the duplex units).

Pursuant to (MMC) Section XI-10-13.08, the maximum floor area allowed for the Junior ADU shall be five hundred (500) square feet.

Pursuant to (MMC) Section XI-10-13.08, a recorded deed restriction will be required stating that the owner shall reside in one of the units constructed on the property.

Note: An ADU / Junior ADU is not permitted when the lot is split pursuant to SB9