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Simi Valley · Building on your lot

Sheds, garages and other accessory structures in Simi Valley

On lots under 1 acre, accessory structures are limited to 30% of the main building's square footage, up to 1,200 square feet.

Key points

  • Accessory size: On lots under 1 acre, accessory structures are limited to 30% of the main building's square footage, up to 1,200 square feet.

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
Size or lot coverage
  • Together, accessory structures can cover at most 40% of any required yard.
    Applies: Residential accessory structures.
    § 9-44.220 · code text
    Accessory structures shall not cumulatively cover more than 40 percent of any required yard and shall maintain a minimum six (6) foot separation from all on-site structures.
  • Each at most 30% of the main building's square footage, up to 1,200 square feet.
    Applies: Lots under 1 acre.
    § 9-44.220 · code text
    On lots less than one acre in size, each accessory residential structure shall not be larger than 30 percent of the square footage of the primary structure as defined in subsection B.1 up to a maximum of 1,200 square feet.
  • Can be increased up to 2,000 square feet.
    Applies: Lots under 1 acre, through an administrative action approval.
    § 9-44.220 · code text
    The maximum size of an accessory residential structure may be increased beyond the 30 percent limit up to 2,000 square feet in compliance with Section 9-52.030 Administrative Actions.
  • Each at most 30% of the main building's square footage, up to 2,000 square feet.
    Applies: Lots of 1 acre or more.
    § 9-44.220 · code text
    On lots of one acre or more, each accessory residential structure shall not exceed 30 percent of the square footage of the primary structure as defined in subsection B.1 up to a maximum of 2,000 square feet.
  • Can be increased beyond the 30% limit, up to 2,000 square feet.
    Applies: Lots of 1 acre or more, through an administrative action approval.
    § 9-44.220 · code text
    The maximum size of an accessory residential structure may be increased beyond the 30 percent limit, up to 2,000 square feet in compliance with Section 9-52.030 Administrative Actions, and beyond 2,000 square feet in compliance with Section 9-52.070 Conditional Use Permits.
  • Can be larger than 2,000 square feet.
    Applies: Lots of 1 acre or more, with a conditional use permit.
    § 9-44.220 · code text
    The maximum size of an accessory residential structure may be increased beyond the 30 percent limit, up to 2,000 square feet in compliance with Section 9-52.030 Administrative Actions, and beyond 2,000 square feet in compliance with Section 9-52.070 Conditional Use Permits.
  • Each accessory structure can be at most 2,000 square feet.
    Applies: Properties in an Animal Overlay Zone (A), (H) or (L).
    § 9-44.220 · code text
    On properties within an Animal Overlay Zone (A), (H), (L), each accessory residential structure shall not exceed 2,000 square feet.
  • Can be larger than 2,000 square feet.
    Applies: Lots of 1 acre or more in an Animal Overlay Zone, with a conditional use permit.
    § 9-44.220 · code text
    On lots of one acre or more in size and within an Animal Overlay Zone, the maximum size of an accessory residential structure may be increased beyond 2,000 square feet in compliance with Section 9-52.070 Conditional Use Permits.
Distance from the house
  • At least 6 feet from all other structures on the lot.
    Applies: Residential accessory structures.
    § 9-44.220 · code text
    Accessory structures shall not cumulatively cover more than 40 percent of any required yard and shall maintain a minimum six (6) foot separation from all on-site structures.

Who this affects

HomeownersContractorsDesigners

Frequently asked questions

How big can a shed or accessory building be in Simi Valley?

On lots under 1 acre, accessory structures are limited to 30% of the main building's square footage, up to 1,200 square feet.

General information, not legal advice.

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