San Jose does not require a building permit for a detached accessory building 120 square feet or smaller unless it has electrical or plumbing work; a structure over 120 square feet requires a building permit.
Setbacks, height, lot coverage, fire separation, utilities, easements, and an accessory structure over 650 square feet can trigger additional review.
What this tells youComputed rule answer
How precise this isComputed rule answer
Official data checkedSan Jose accessory buildings and structures
Next stepCheck the official shed/accessory-structure rules with your project dimensions.
No building permitDetached accessory building 120 sq ft or smaller with no electrical or plumbing work
Building permitOver 120 sq ft, or electrical/plumbing scope
Additional reviewStructures over 650 sq ft and zoning/site constraints