Dubuque, IA Zoning Overlays & Bonuses: Density Bonus Law (2026)

City Code section 16-11-11-2 conditions the bonus on setting aside environmentally sensitive land, public park land, or common open space; section 16-11-11-1(D)(1) sets the minimum open space at 40 percent of the subdivision to qualify. The subdivider must first submit a development yield analysis, a table showing the maximum dwelling units the underlying zoning district would otherwise permit given minimum lot size, lot width and setback standards, excluding land that is undevelopable under other laws such as floodplain, wetland, steep-slope or drainageway restrictions. Section 16-11-11-2(B) then fixes the bonus itself: the overall development density equals that yield-analysis figure plus 20 percent.

To use the added density, section 16-11-11-2(C) lets the subdivider plat smaller lots than the zoning district's lot size, yard and bulk rules would otherwise allow, subject to Zoning Advisory Commission and City Council approval, so long as the smaller lots are not so narrow or irregular that a principal structure could not be built on them consistent with the district's permitted uses and setback and lot-coverage requirements. The clustering requirement in section 16-11-11-1(C) requires residential clusters of at least five units sited to avoid environmentally sensitive areas identified by the Iowa DNR.

This bonus tool sits within the broader Sustainable Subdivision Development Tools framework of section 16-11-10, where new major subdivisions must independently score at least 40 points from a menu of sustainable design choices.