SB 9 Applications

What is SB 9?

Senate Bill (SB) 9, signed into law on September 16, 2021, allows for “ministerial approval” of up to two primary dwelling units on a single-family lot. Alternatively, it also allows for splitting a parcel zoned for single-family development into two separate legal parcels, and the construction of up to two units on each resulting parcel.  Ministerial approval is approval given at the staff level that only requires a project conform with a fixed standard or objective measurement and requires no discretionary oversight or judgment of the project.

The Town adopted Chapter 17.53 “Regulations and Objective Standards for Urban Lot Splits and Development Projects Sought Pursuant to Government Code Sections 65852.21 and 66411.7” as part of the Atherton Municipal Code (AMC). 

What exactly does SB 9 allow me to do? 

SB 9 allows property owners to add units to their property in two different ways: 

  1. SB 9 allows up to two units on a parcel so property owners can add a single unit to an existing unit or construct two new units on a vacant parcel
  2. SB 9 allows parcels to be split into separate parcels, each of which may have up to two units (including existing and new units).


SB 9 Urban Lot Split Checklist

SB 9 2-Unit Development Checklist

Affidavit of Intent to Occupy

Tentative Parcel Map Requirements per AMC Chapter 16.16