Jefferson County, WI Building Setbacks & Zoning: Lot Coverage Limits (2026)

Jefferson County Code § 22-132, "Maximum lot coverage by buildings," limits combined coverage from principal and accessory structures to 30 percent of a lot's existing area in the R-1 Residential-Sewered District, one of the district-specific dimensional standards set out in Article III, Division 2, Subdivision II. The 30 percent figure covers buildings only, distinct from the separate 500-square-foot combined cap on non-building residential accessory features like driveways, patios and pools defined under § 22-7. Together with the district's other numbers, an 8,000-square-foot minimum lot (10,000 in shoreland areas) under § 22-126, 80-foot minimum width under § 22-127, 80-foot minimum depth under § 22-128, and the 25-foot rear and 10-foot side yard setbacks under § 22-129, this coverage limit shapes how much of a residential lot can actually be built on.

A homeowner planning an addition or a large accessory garage that would push combined building footprint past 30 percent of lot area would need to either reduce the design or apply for an area variance from the board of adjustment under § 22-59, showing the 30 percent cap creates an unnecessary hardship tied to unique conditions on the specific parcel rather than simple preference for more building area.