Hidden Hills · Building on your lot

Lot splits under SB 9 in Hidden Hills

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

What Hidden Hills's code says

Hidden Hills code What Hidden Hills's code adds
How the lot may be divided	Each new lot must be at least 40% of the original lot's area. § 5-2O-4 · code text The newly created lots shall not be smaller than 40 percent of the area of the original lot.
Unit size	No more than 800 square feet of gross floor area. Applies: Applies to new SB 9 units, which also may be no more than one story and 16 feet high. § 5-2O-3 · code text No residential unit shall exceed 800 square feet in gross floor area.
Minimum new lot size	Each new lot must be at least 1,200 square feet. § 5-2O-4 · code text Each lot created by the parcel map shall have a minimum area of 1,200 square feet.
Setbacks	At least 4 feet from side and rear property lines. Applies: Except as allowed by state law. § 5-2O-3 · code text Each residential unit shall have a minimum setback of four feet from side and rear property lines except as allowed by Government Code Section 65852.21.
Standards	At least 20 feet of street frontage or 40% of the original lot's frontage, whichever is greater. Applies: Applies to each new lot. § 5-2O-4 · code text Each lot created by the parcel map shall have a minimum street frontage of 20 feet or 40 percent of the street frontage of the original lot, whichever is greater. Units must sit one behind the other, as seen from the street. Applies: Detached units; the front unit must be at least as wide and tall as the rear, which may not be visible from the front. § 5-2O-3 · code text The units shall be located one in front of the other in relation to the street. One unit's door faces the street, the other's a side or rear line; units may not be mirror images. Applies: Applies to attached residential units. § 5-2O-3 · code text One residential unit shall have a door facing the street and one residential unit shall have a door facing the side or rear property line. No more than 2 residential units per new lot, including any ADU or JADU. Applies: Applies to lots created by the parcel map. § 5-2O-3 · code text No lot created by the parcel map shall have more than two residential units inclusive of any ADU or JADU. New driveways may be no wider than 12 feet, or the Fire Code minimum, whichever is greater. Applies: Applies to SB 9 development. § 5-2O-3 · code text Any new driveway or driveway extension constructed to serve development pursuant to this Article shall not exceed 12 feet in width, or the minimum necessary to meet Fire Code standards, whichever is greater.
Parking	At least 1 off-street parking space. Applies: Applies to each new residential unit. § 5-2O-3 · code text A minimum of one off-street parking space shall be provided for each new residential unit, except that no off-street parking is required if either of the following apply: No off-street parking is required. Applies: Applies to lots within 1/2 mile walk of a high-quality transit corridor or major transit stop. § 5-2O-3 · code text The lot is located within one-half mile walking distance of either: (i) a high-quality transit corridor as defined in Public Resources Code Section 21155(b); or (ii) a major transit stop as defined in Public Resources Code Section 21064.3. No off-street parking is required. Applies: Applies when a car-share vehicle is within 1 block of the lot. § 5-2O-3 · code text There is a car share vehicle located within one block of the lot.

Who this affects

HomeownersContractorsDesigners

Frequently asked questions

Can I split my lot under SB 9 in Hidden Hills?

Hidden Hills's code: Each new lot must be at least 1,200 square feet. (§ 5-2O-4); No more than 800 square feet of gross floor area. (Applies to new SB 9 units, which also may be no more than one story and 16 feet high.) (§ 5-2O-3).

General information, not legal advice.

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