St. Peters, MO Accessory Structures: Shed & Carport Rules (2026)

Section 405.270(A) of the St. Peters Municipal Code governs every accessory structure in the City, from garden sheds to detached garages, swimming pools and greenhouses. Any attached structure counts as part of the main house and must meet the same district standards, but a detached accessory building gets its own rules: it must sit at least six feet from any side or rear property line, and it cannot be placed in the front or side building setback area at all, with one exception for through lots, where it may extend past the front line that runs parallel to the rear of the house while still keeping the six-foot setback.

Temporary items such as deer stands and portable restrooms fall under the same setback ban, though the Administrative Officer can allow a portable restroom in the front yard during construction if there's nowhere else to put it. Size is capped relative to the house itself: under (A)(5), an accessory building in a residential district cannot exceed one-half of the principal building's ground floor area, so there's no flat square-footage limit, just a ratio. Subsection (A)(4) separately bars locating any building, accessory or principal, within a designated utility easement, and (A)(6) prohibits using any accessory building for a separate business or use apart from the main property. In non-residential districts, accessory buildings and trash enclosures instead follow whatever site development plan the Planning Department approved for that property.