St. Peters, MO Building Setbacks & Zoning: Lot Coverage Limits (2026)

Section 405.130(G) sets the percentage-of-lot-coverage standard for St. Peters' "R-1" Single-Family Residential District: all buildings, including accessory buildings, and paved areas such as driveways and patios, may not cover more than fifty percent of the lot, with swimming pools specifically excluded from that fifty-percent count. The identical fifty-percent cap and swimming-pool exclusion apply next door in the "R-1(A)" district under Section 405.140(G). The coverage rule works together with the district's other dimensional standards: a minimum lot size of seven thousand square feet (twelve thousand square feet on plats approved after January 1, 2001) under Section 405.130(F), and yard setbacks in Section 405.130(H) that already remove a large share of any lot from where impervious surface could be added.

Detached residential accessory buildings, capped at five hundred square feet (or one thousand square feet on lots of eighteen thousand square feet or more) under Section 405.130(H)(1)(e), also count toward the fifty-percent ceiling. The Planning, Community and Economic Development Department checks proposed site and building plans against this coverage limit at the building permit stage, and additions or new patios, garages, or driveways that would push a lot's built-and-paved footprint past half its area require either redesign or a variance from the Board of Adjustment.