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San Marino · Building on your lot

Lot splits under SB 9 in San Marino

San Marino'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 San Marino Municipal Code it was read from, with the code text one click away (checked October 2026). General information, not legal advice.

What San Marino's code says

San Marino code What San Marino's code adds
How the lot may be divided
  • Each new parcel must be at least 40% of the original lot area.
    Applies: Applies to urban lot splits in the R-1 zone.
    § 22.06.05 · code text
    one parcel shall not be smaller than 40 percent of the lot area of the original parcel proposed for subdivision.
Unit size
  • Units may be no more than 800 square feet.
    Applies: Applies to units on lots created by an urban lot split in the R-1 zone.
    § 22.06.05 · code text
    Unit size shall be not greater than 800 square feet.
Minimum new lot size
  • Each new parcel must be at least 1,200 square feet.
    Applies: Applies to both new parcels of an urban lot split in the R-1 zone.
    § 22.06.05 · code text
    Both newly created parcels shall be no smaller than 1,200 square feet.
Standards
  • Must meet all objective zoning, subdivision and design review standards, including the city's two-unit design and configuration standards.
    Applies: Applies to development on lots created by an urban lot split.
    § 22.06.06 · code text
    Development proposed on lots created by an urban lot split subdivision shall comply with any and all objective zoning standards, objective subdivision standards, requirements in this Article, and objective design review standards applicable to the parcel based on the underlying zoning, the Two-Unit Residential Development Design Standards and the Two-Unit Residential Development and Urban Lot Split Configuration Standards
  • Standards are reduced if they would block 2 units on either parcel or force units under 800 square feet.
    Applies: Applies only when the standards would have that effect.
    § 22.06.06 · code text
    provided, however, that the application of such standards shall be reduced if the standards would have the effect of physically precluding the construction of two units on either of the resulting parcels created pursuant to this chapter or would result in a unit size of less than 800 square feet.

Who this affects

HomeownersContractorsDesigners

Frequently asked questions

Can I split my lot under SB 9 in San Marino?

San Marino's code: Each new parcel must be at least 1,200 square feet. (Applies to both new parcels of an urban lot split in the R-1 zone.) (§ 22.06.05); Units may be no more than 800 square feet. (Applies to units on lots created by an urban lot split in the R-1 zone.) (§ 22.06.05).

General information, not legal advice.

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

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