Blue Earth County, MN Building Setbacks & Zoning: Lot Coverage Limits (2026)

Blue Earth County Code Sec. 24-163 sets two distinct lot-coverage limits for the RR district. Subsection (f) caps impervious surfaces, meaning driveways, patios, roofs, and other surfaces that block water infiltration, at not more than 40 percent of the lot area. Subsection (h) separately caps lot coverage by buildings themselves at not more than 25 percent of the lot area, a tighter number because it only counts building footprints and excludes non-building impervious surfaces like a gravel driveway. Both percentages are calculated against the same one-acre minimum buildable lot required in the RR district under Sec.

24-163(g), so a typical one-acre RR lot may seal off no more than about 40 percent of its area with impervious surface, and cover no more than about a quarter of its area with buildings. The identical impervious-surface and building-coverage structure repeats district by district throughout chapter 24, but the percentages differ: the RT district, for comparison, allows 45 percent impervious coverage and 30 percent building coverage under Sec. 24-193(f) and (h). A property owner planning a new home, garage, or pole barn in unincorporated Blue Earth County has to size the project against both ceilings, not just one, before the zoning administrator will issue a construction permit under Sec. 24-43.