Jefferson County, CO Accessory Structures: Shed & Carport Rules (2026)

Section 19.B.6 provides that accessory uses in all residential zone districts cannot exceed the square footage of the primary residence, and that accessory square footage includes attached and detached garages, sheds, ADUs, and all listed accessory uses. Section 19.B.7 adds that the footprint of an accessory structure may not exceed 75% of the footprint of the primary structure (counting attached garages and enclosed porches, but not decks or covered porches). A carport, like any accessory building, must meet the setback and height limits of the underlying zone district. Jefferson County has no single county-wide carport dimension rule beyond these accessory-structure caps; the applicable zone district controls setbacks and height.