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Palo Alto · Building on your lot

Lot splits under SB 9 in Palo Alto

Palo Alto's own rules on lot splits under SB 9, with the code text for every value.

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Each rule below links to the section of the Palo Alto Municipal Code it was read from, with the code text one click away (checked October 2026). General information, not legal advice.

What Palo Alto's code says

Palo Alto code What Palo Alto's code adds
How the lot may be divided
  • Lots of about equal area; none smaller than 40% of the original lot.
    Applies: Applies to urban lot splits.
    § 21.10.040 · code text
    The lots created by an Urban Lot Split must be of approximately equal area, such that no resulting parcel shall be smaller than 40 percent of the lot area of the original parcel proposed for subdivision.
Minimum new lot size
  • At least 1,200 square feet.
    § 21.10.040 · code text
    The minimum size for a parcel created by an Urban Lot Split is 1,200 square feet.
Standards
  • No new lot line may cut through a structure or leave more than 2 units on a resulting parcel.
    Applies: Applies where existing homes on the property will remain.
    § 21.10.040 · code text
    Where existing dwelling units on the property are to remain, no lot line may be created under this Chapter in a manner that would bisect any structure or that would result in more than two dwelling units on any resulting parcel.
  • No more than 2 dwelling units per lot.
    § 21.10.050 · code text
    That no more than two dwelling units may be permitted on each lot.
Owner occupancy
  • Owner affidavit: live in one unit as principal residence for at least 3 years from parcel map recording.
    Applies: Applies to urban lot splits.
    § 21.10.050 · code text
    The owner intends to occupy one of the housing units located on a lot created by the parcel map as their principal residence for a minimum of three years from the date of the recording of the parcel map.

Who this affects

HomeownersContractorsDesigners

Frequently asked questions

Can I split my lot under SB 9 in Palo Alto?

Palo Alto's code: At least 1,200 square feet. (§ 21.10.040); Owner affidavit: live in one unit as principal residence for at least 3 years from parcel map recording. (Applies to urban lot splits.) (§ 21.10.050).

General information, not legal advice.

Ask about a specific Palo Alto property

Ask GoCodebook how Palo Alto's lot splits under SB 9 rules apply to your situation and get an answer that cites the section.

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Palo Alto Municipal Code — full text