Black Hawk County, IA Building Setbacks & Zoning: Lot Coverage Limits (2026)

010(D) caps how much of a required rear yard an accessory building can fill: no more than 30 percent of the rear yard. The limit sits inside the zoning title's exceptions-and-variations section, which qualifies the base yard and lot standards set for each of the county's zoning districts. 70 reinforces the same 30 percent figure from a different angle: an accessory building that is not part of the main building shall not occupy more than 30 percent of the required rear yard and shall not exceed 20 feet in height, though that same section carves out an exception allowing a 440-square-foot garage even on a minimum-size rear yard.

70 adds further caps on accessory building size for a one- or two-family residence: the total floor area cannot exceed 1,000 square feet unless the buildings together stay under six percent of the lot, and in no case can total accessory floor area on such a lot exceed 9,000 square feet. 010. The 30 percent rear-yard coverage cap applies only in unincorporated Black Hawk County; Waterloo, Cedar Falls and the county's other cities set their own accessory-structure coverage limits inside city limits.