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Lot splits under SB 9 in San Jose

San Jose's own rules on lot splits under sb 9, with the code text for every value, and the state law underneath.

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

What San Jose's code says

San Jose code What San Jose's code adds
Unit size
  • Floor area ratio and lot coverage limits cannot block a second unit of up to 800 square feet.
    Applies: Applies to a second dwelling unit on a lot with an existing or proposed dwelling unit.
    § 20.30.852 · code text
    The Floor Area Ratio or lot coverage calculations shall not preclude a second dwelling unit with a maximum eight hundred (800) square feet on a lot that comprises of an existing or proposed dwelling unit.
Setbacks
  • At least 4 feet.
    Applies: Applies to all side and rear property lines.
    § 20.30.852 · code text
    The minimum setbacks from all side and rear property lines shall be four (4) feet.
Standards
  • At most 2 main dwelling units per lot.
    Applies: Applies to two-unit developments.
    § 20.30.820 · code text
    A maximum of two (2) main dwelling units is permitted per lot, either as two (2) one-family dwellings or one (1) two-family dwelling.
  • No more than 4 units on an undivided lot, including ADUs and JADUs.
    Applies: Applies to two-unit developments in the R-1 district.
    § 20.30.820 · code text
    The total number of units shall not exceed four (4) on any undivided lot or two (2) on each subdivided lot, inclusive of Accessory Dwelling Units (ADUs) or Junior Accessory Dwelling Units (JADUs).
  • Buildings may be at most 30 feet or 2 stories tall, whichever is lower.
    Applies: Applies to all buildings.
    § 20.30.852 · code text
    The maximum building height shall not exceed thirty (30) feet or two (2) stories, whichever is lower.
  • Roof height at most 25 feet.
    Applies: Applies to detached or attached two-story units within 15 feet of the rear property line.
    § 20.30.820 · code text
    Any detached or attached two-story units located within fifteen (15) feet of the rear property line shall be limited to a maximum height of twenty-five (25) feet.
  • Floor area ratio of at most 0.65.
    Applies: Applies to each lot.
    § 20.30.852 · code text
    For purposes of this Part, the maximum Floor Area Ratio for each lot shall be 0.65, calculated in accordance with Section 20.100.1020 of this Code.
  • Lot coverage of at most 75%.
    Applies: Applies to lots of 1,200 to 2,500 square feet.
    § 20.30.852 · code text
    1,200 - 2,500 | 75%
  • Lot coverage of at most 65%.
    Applies: Applies to lots of 2,501 to 9,000 square feet.
    § 20.30.852 · code text
    2,501 - 9,000 | 65%
  • Lot coverage of at most 60%.
    Applies: Applies to lots larger than 9,000 square feet.
    § 20.30.852 · code text
    Greater than 9,000 | 60%
  • Each lot needs at least 30 feet of street frontage and an average width of 30 feet.
    Applies: Applies when both lots from an urban lot split will not have 55 feet of frontage on a public right-of-way.
    § 20.30.810 · code text
    each lot shall have a minimum of thirty (30) feet of frontage on a public right-of-way and an average width of thirty (30) feet
  • One lot needs an access corridor of 4 to 7 feet, or 12 to 15 feet.
    Applies: Applies when both lots from an urban lot split will not have 30 feet of frontage on a public right-of-way.
    § 20.30.810 · code text
    one of the lots shall be provided with an access corridor of either at least four (4) but no more than seven (7) feet or at least twelve (12) feet but no more than fifteen (15) feet of frontage
  • At most 2 dwelling units per lot, including ADUs and JADUs.
    Applies: Applies to lots created through an urban lot split.
    § 20.30.810 · code text
    Lots created through an Urban Lot Split shall not each contain more than two (2) dwelling units, inclusive of Accessory Dwelling Units and Junior Accessory Dwelling Units.
Owner occupancy
  • The applicant signs an affidavit to live in one unit as their main home for at least 3 years.
    Applies: Counted from the date the urban lot split is approved.
    § 20.30.830 · code text
    The applicant shall sign an affidavit stating that the applicant intends to occupy one of the housing units as their principal residence for a minimum of three (3) years from the date of the approval of the Urban Lot Split.

Who this affects

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Frequently asked questions

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

San Jose's code: Floor area ratio and lot coverage limits cannot block a second unit of up to 800 square feet. (Applies to a second dwelling unit on a lot with an existing or proposed dwelling unit.) (§ 20.30.852); At least 4 feet. (Applies to all side and rear property lines.) (§ 20.30.852).

General information, not legal advice.

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