Senate Bill 9 (SB9)

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Senate Bill 9 (SB 9) is intended to support the increased supply of moderately priced homes by encouraging building of smaller houses on small lots. This legislation is one way the State is addressing California’s housing shortage and affordability crisis, often referred to as “missing middle housing”. Effective January 1, 2022, SB 9 can be used to add new homes to an existing parcel, divide and existing house into multiple units, and/or divide a parcel and add homes. 

Which types of projects are allowed?

Urban Lot Split - Allows for ministerial approval of a one-time subdivision of an existing single-family residential zoned parcel into two parcels. Each lot must be at least 40 percent of the original lot's size, or at least 1,200 square-feet, whichever is greater.


Urban Housing Development - Allows for ministerial approval of the development of two principal housing units on an eligible single-family zoned parcel. Project types include developing up to two new housing units on a vacant parcel or developing one new housing unit on a parcel with an existing housing unit.   

Where is an SB 9 Urban Housing Development and/or Urban Lot Split allowed?

SB 9 applies to single-family residential zoning districts only. In Moraga, these zoning districts are the One, Two, and Three Dwelling Units per Acre Residential Districts (1-DUA, 2-DUA, and 3-DUA). The property must also meet the following eligibility criteria:

  • The parcel is not located on prime farmland or farmland of statewide importance, wetlands, habitat for protected species, or conservation lands or easements.
  • The parcel is not located in a high or very high fire zone, hazardous waste site, earthquake fault zone or flood area, unless certain additional requirements are met to reduce hazards. 
  • The project does not include demolition of existing housing units that are: rent restricted for moderate, low, or very low income; rent-controlled by a public entity, occupied by a tenant in the last three years, or have been withdrawn from the rental market in the past 15 years via an Ellis Act eviction.
  • The project is not located in a historic district or on a site included on the State Historic Resources Inventory, on a site designated as a town landmark or on a site with historic resources. 

What are the development standards for an Urban Housing Development? 

An Urban Housing Development is a development with a maximum of two principal dwelling units (attached or detached) on a single-family residential parcel. Any existing dwellings, including ADUs and JADUs, count toward the two unit maximum. The development must comply with the following development standards:

  • Setbacks: Minimum four-foot interior side and rear yard. Front yard and exterior side yard setbacks must comply with the underlying zoning district standard unless it precludes the development of two 800 square-foot units on the property. Setbacks are found in Chapter 8.24 of the Municipal Code. 
  • Off-Street Parking: Minimum of one off-street parking space per unit. 
  • Design: The development must comply with the objective standards of both the zoning district and the Town of Moraga Design Guidelines, unless it precludes the development of two 800 square-foot units on the property. 

What are the regulations for an Urban Lot Split?

An Urban Lot Split is the subdivision of an existing single-family residential parcel into two parcels. The law allows a one-time lot split, meaning that any parcel previously subdivided under the provisions of SB 9 is not eligible for a second subdivision under SB 9.  The lot split must comply with the following regulations:

  • Each new lot must be at least 1,200 square feet in size.
  • The Urban Lot Split must result in two new lots of approximately equal size (minimum 60/40).
  • The property owner must state their intention to occupy one of the units as their principal residence for a minimum of three years.
  • The property owner cannot not act in concert with the owner of an adjacent parcel.
  • The Town’s Public Works Department may require easements for public services and utilities as well as access to the public right-of-way, but cannot require dedications or offsite improvement conditions. 
  • Up to two (2) dwelling units are allowed on each lot, for a total of four (4) dwelling units. The dwelling units must comply with the development standards for an Urban Housing Development listed above. 

Can an SB 9 project include the development of an ADU or JADU?

The construction of ADUs and JADUs are subject to the Town’s ADU ordinance, codified in Chapter 8.124 of the Moraga Municipal Code. More information about the ADU development regulations is available on the Town’s website at:

What is ministerial approval?

While a discretionary review process requires a local jurisdiction to exercise judgement and deliberation, including through public hearings and notification, in deciding whether and how to carry out or approve a project, a ministerial approval is a streamlined decision that involves little or no personal judgement by a public official. This means that the review process consists only of staff’s assessment of the project’s compliance with objective zoning and design standards, and staff must issue a decision (or approval) within certain timelines. The process does not include public hearings or neighborhood notification.

How do I apply for an Urban Housing Development and/or an Urban Lot Split?

It is strongly recommended that property owners interested in an SB 9 project contact a planner before submitting an application to review the eligibility criteria and other applicable regulations. Planning Department staff are available by email, phone 925-888-7040, and in person at 329 Rheem Boulevard. It is also recommended to consult a qualified professional to develop a plan that reflects the specific and sometimes unique conditions of the property, as well as the needs and goals for the project. 

Complete the appropriate application and forms located on the Application Forms webpage. Materials may be submitted either electronically by emailing or in-person during The Planning Department’s normal business hours. Application fees can be found on the Town’s Master Fee Schedule

Where can I learn more about SB 9?

The legislation can be found online at:

The California Department of Housing and Community Development Fact Sheet can be found online at:

Download the Town’s SB 9 Frequently Asked Questions (FAQ) document.