Simi Valley, CA Building Setbacks & Zoning: Lot Coverage Limits (2026)

220(A) sets the development standards for residential accessory structures, cross-referencing the height and setback rules in SVMC Sections 9-24 and 9-30 before adding coverage-specific limits of its own. Subsection (A)(4) provides that accessory structures shall not cumulatively cover more than 40 percent of any required yard and shall maintain a minimum six-foot separation from all on-site structures. The 40 percent figure is cumulative, so a homeowner adding a shed, a detached garage, and a pool cabana in the same required side or rear yard must keep the combined footprint of all three under that 40 percent ceiling, not just each structure individually.

Size limits layer on top of the coverage cap: under Subsection B, an accessory structure on a lot under one acre cannot exceed 30 percent of the primary structure's square footage, up to a maximum of 1,200 square feet, or up to 2,000 square feet with Administrative Action approval, and on lots of an acre or more the cap rises to 2,000 square feet, with larger sizes requiring a Conditional Use Permit. Subsection C further limits the number of accessory structures 1,200 square feet or larger to two per lot on parcels under an acre, or two per acre on larger parcels, counting ADUs toward that total.