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Building on a hillside in Simi Valley

Simi Valley's own rules on building on a hillside, with the code text for every value.

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

What Simi Valley's code says

Simi Valley code What Simi Valley's code adds
Soils or geology report
  • A soils engineering report and a geology report are required with each application.
    Applies: Development under the hillside performance standards. May be waived for 4 or fewer homes or lots.
    § 9-32.180 · code text
    A soils engineering report shall be submitted with each application for development under the requirements of the performance standards.
Grading and retaining walls
  • No manufactured slope may be higher than 30 feet, including any retaining wall built into it.
    Applies: Grading of more than 1,000 cubic yards on land under the hillside performance standards.
    § 9-32.110 · code text
    No manufactured slope shall exceed 30 feet in height, [except that slopes required for public streets may exceed 30 feet in height if no feasible alternative consistent with the findings (Section 9-1.1605 of this Article) exists].
When hillside rules apply
  • Natural slopes of 20% or more.
    Applies: Grading on such slopes over 30 feet high with a horizontal run of 100 feet or more needs Commission or Council approval.
    § 9-32.110 · code text
    Grading on naturally occurring slopes of 20 percent grade or more which have a vertical height of more than 30 feet and a horizontal run of 100 feet or more shall not occur unless the grading becomes necessary and is specifically approved by the Commission or Council after making the findings.
  • Slopes over 20%.
    Applies: Homes, additions or accessory buildings on lots legally subdivided by July 21, 1986 are exempt unless grading such slopes, ridgelines, or over 1,000 cubic yards.
    § 9-32.040 · code text
    The construction of a residential dwelling unit, or additions thereto, and accessory buildings on a legally subdivided, residentially-zoned parcel as of July 21, 1986, which does not involve grading for structures on visually prominent ridgelines or on land with a slope in excess of 20 percent or grading in excess of 1,000 cubic yards;

Who this affects

HomeownersContractorsDesigners

Frequently asked questions

What extra rules apply to a hillside lot in Simi Valley?

Simi Valley's code: Natural slopes of 20% or more. (Grading on such slopes over 30 feet high with a horizontal run of 100 feet or more needs Commission or Council approval.) (§ 9-32.110); No manufactured slope may be higher than 30 feet, including any retaining wall built into it. (Grading of more than 1,000 cubic yards on land under the hillside performance standards.) (§ 9-32.110).

General information, not legal advice.

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Simi Valley Municipal Code — full text