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San Diego · Building on your lot

Sheds, garages and other accessory structures in San Diego

In residential zones, non-habitable accessory buildings combined, not counting garages, are limited to 25 percent of the premises' allowable gross floor area.

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Key points

  • Accessory buildings: In residential zones, non-habitable accessory buildings combined, not counting garages, are limited to 25 percent of the premises' allowable gross floor area.

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

What San Diego's code says

San Diego code What San Diego's code adds
Maximum height
  • At most 21 feet.
    Applies: Flat-roofed guest quarters or habitable accessory buildings above a garage or accessory building; single-home lots only; no kitchen; not rented or sold separately.
    § 141.0307 · code text
    For guest quarters or habitable accessory buildings located above a garage or other accessory building, the maximum structure height for flat-roofed structures is 21 feet.
  • At most 30 feet.
    Applies: 3:12-or-steeper sloped roofs on guest quarters or habitable accessory buildings above garages or accessory buildings; single-home lots only; no kitchen; not rented or sold separately.
    § 141.0307 · code text
    For sloped-roofed structures with a roof pitch of at least 3:12 (3 vertical feet to 12 horizontal feet), the maximum structure height is 30 feet.
Size or lot coverage
  • At most 25% of the lot's allowable gross floor area.
    Applies: Guest quarters or habitable accessory buildings, attached or detached; single-home lots only; counted in the floor area ratio.
    § 141.0307 · code text
    Guest quarters or habitable accessory buildings may occupy a maximum of 25 percent of the allowable gross floor area of the premises.
  • All non-habitable accessory buildings combined, except garages, can be at most 25% of allowable gross floor area.
    Applies: Residential zones; in the Coastal Overlay Zone, older rules may apply until the Coastal Commission certifies the latest changes.
    § 131.0448 · code text
    However, the square footage of all non-habitable accessory buildings excluding garages cannot exceed 25 percent of the allowable gross floor area of the premises.

Who this affects

HomeownersContractorsDesigners

Frequently asked questions

How big can a shed or accessory building be in San Diego?

In residential zones, non-habitable accessory buildings combined, not counting garages, are limited to 25 percent of the premises' allowable gross floor area.

General information, not legal advice.

Ask about a specific San Diego property

Ask GoCodebook how San Diego's sheds, garages and other accessory structures rules apply to your situation and get an answer that cites the section.

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