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Lot splits under SB 9 in Union City

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

What Union City's code says

Union City code What Union City's code adds
How the lot may be divided
  • One of the 2 new parcels may not be smaller than 40% of the original lot area.
    Applies: Applies to an urban lot split.
    § 18.31.100 · code text
    one of the two parcels resulting from the urban lot split shall not be smaller than 40% of the lot area of the original parcel.
Unit size
  • No single unit may be larger than 2,000 square feet.
    Applies: Applies to a unit on an SB 9 parcel.
    § 18.31.090 · code text
    except that in no case shall a single unit be larger than 2,000 square feet.
Minimum new lot size
  • Each new lot must be at least 1,200 square feet.
    Applies: Applies to each new lot.
    § 18.31.100 · code text
    Each lot shall be a minimum size of 1,200 square feet.
Setbacks
  • At least 4 feet from interior side and rear lot lines.
    Applies: Applies to SB 9 units.
    § 18.31.090 · code text
    SB 9 units shall be setback from interior side and rear lot lines a minimum of four feet.
  • No setback is required.
    Applies: Applies to an existing structure, or one rebuilt in the same place and to the same size.
    § 18.31.090 · code text
    No setback shall be required for an existing structure, or a structure constructed in the same location and to the same dimensions as an existing structure.
  • The street side yard must be at least 10 feet.
    Applies: Applies to the street side of a corner lot.
    § 18.31.090 · code text
    On the street side of a corner lot, the street side yard shall not be less than 10 feet.
Standards
  • No more than 16 feet high.
    Applies: The part of an SB 9 unit between the 4-foot setback line and the zone's normal yard limit.
    § 18.31.090 · code text
    The maximum height of the portion of a SB 9 unit located between the four foot setback line established by this chapter and the limit of the rear, side, or street side yard area established by zoning district is 16 feet, as measured from the lowest grade adjacent to the structure to the highest ridge or top of the structure.
  • At least 30 feet of street frontage, with direct vehicle access.
    Applies: Applies to each parcel from an urban lot split, except flag lots.
    § 18.31.100 · code text
    Each parcel shall provide for direct vehicular access to and have a minimum frontage of 30 feet on the public right-of-way, except for flag lots, where the frontage shall be the width needed to meet access standards as specified in this chapter.
  • Lot depth shall not exceed two times the lot width
    Applies: each new lot; the Director may approve a depth between two and three times the width
    § 18.31.100 · code text
    Lot depth shall not exceed two times the lot width except as provided below.
  • The access corridor must be at least 12 feet wide and paved.
    Applies: Applies to flag lots, unless the Fire Department needs more width.
    § 18.31.100 · code text
    The minimum width of the access corridor portion of the flag lot shall be 12 feet paved, except where greater width is required for Fire Department access.
  • Roof pitch of at least 2.5 inches of rise for each 12 inches of run.
    Applies: Applies to new structures in an SB 9 housing project.
    § 18.31.110 · code text
    New structures shall provide a roof pitch no less than two and one-half (2.5) inches of vertical rise for each 12 inches of horizontal run.
  • Second stories set back at least 6 feet from the front wall and 18 inches from side and rear walls.
    Applies: Applies to second-story facades in an SB 9 housing project.
    § 18.31.110 · code text
    a. A minimum of a six foot inset from the front wall plane; b. A minimum of an 18 inch inset from the side and rear wall plane;
Owner occupancy
  • Owner signs an affidavit to live in one unit as their main home for at least 3 years from approval.
    Applies: Applies to an urban lot split; not to a community land trust or qualified nonprofit corporation.
    § 18.31.060 · code text
    Applicant shall sign an affidavit on a form provided by the City stating the owner intends to occupy one of the housing units on a resulting parcel as his or her principal residence for a minimum of three years from the date of the approval of the urban lot split, except this shall not apply to a community land trust or a qualified nonprofit corporation.
Parking
  • 1 off-street, covered and enclosed parking space.
    Applies: Per SB 9 unit; none within a 0.5-mile walk of a high-quality transit corridor or major transit stop, or 1 block of permitted car share.
    § 18.31.090 · code text
    One off-street, covered and enclosed parking space shall be provided per SB 9 unit, except if the parcel is located:

Who this affects

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Frequently asked questions

Can I split my lot under SB 9 in Union City?

Union City's code: One of the 2 new parcels may not be smaller than 40% of the original lot area. (Applies to an urban lot split.) (§ 18.31.100); No single unit may be larger than 2,000 square feet. (Applies to a unit on an SB 9 parcel.) (§ 18.31.090).

General information, not legal advice.

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