The quick and simple answer is: you usually don't need a permit if the shed is 120 square feet or less.
Yes, a Zoning Use Permit is required for structures 12 feet or less in any dimension. This permit assures that the structure is located far enough from property lines and other buildings/structures. A building permit is required for anything measuring over 12 feet in any dimension.
How big can my shed be without requiring a building permit? The biggest your shed can be without a permit would be 12x12 (in the state of North Carolina.)
Yes, if this is your primary residence that you own, and you perform all the work yourself. Do I need a permit for a shed or “temporary” structure? Yes, a Zoning Use Permit is required for structures 12 feet or less in any dimension.