Bolingbrook, IL Building Setbacks & Zoning: Lot Coverage Limits (2026)

Chapter 54, the zoning ordinance, sets a separate maximum lot coverage percentage for each residential zoning district rather than one villagewide number. In the E-R estate residence district, a single-family dwelling may cover no more than 20 percent of the lot, while other permitted uses top out at 30 percent (§ 54-116(d)(2)). In the more common R-1 single-family district the single-family cap rises to 25 percent, with other permitted uses still held to 30 percent (§ 54-117(d)(2)). R-2 allows 30 percent coverage for both single-family homes and other uses (§ 54-118(d)(2)), R-3 rises to 35 percent for single-family dwellings (§ 54-119(d)(2)), and R-4, the attached single-family low-density district, allows the highest residential figure at 40 percent (§ 54-120(d)(2)).

The zoning ordinance defines 'lot coverage' in § 54-2 as the percentage of a lot that, viewed directly from above, would be covered by a structure or structures, excluding projecting roof areas, so eaves and overhangs do not count against the limit but the footprint of the house, attached garage and any other roofed structure does. A homeowner adding a room addition, detached garage or accessory structure must keep the combined footprint of all structures on the lot within these percentages, which the zoning administrator checks when reviewing the building permit application.

Because the village straddles the Will and DuPage county line, the percentage that applies depends on the parcel's residential zoning district under the village's own map, not on which county the land sits in.