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

Ames Municipal Code Sec. 29.1114(5) sets the Supplemental Development Standards table that governs every Planned Unit Development (PUD) Overlay in the City of Ames, Iowa, and its Density row carries the city's only local density bonus. A PUD tract must otherwise meet the density requirements of the underlying zoning district, and where a PUD spans more than one district each area follows that district's own density figure: the code is explicit that density transfer is not permitted between zones within the same PUD. The bonus applies on top of that baseline: a development that commits a minimum of 10% of its units, for sale or rent, to households at or below the moderate- or low-income thresholds set by the U.S.

Department of Housing and Urban Development for Ames may add 15% more units than the base zoning density allows, rounding up to the next whole unit or adding at least one dwelling unit, whichever produces the larger increase. The bonus is not self-executing: the applicant must attach an affordable housing plan and a binding agreement committing to maintain that affordability, and both documents travel with the PUD Master Plan through Planning and Housing Division review and City Council approval as part of the rezoning. A separate, narrower incentive applies to infill sites, which may add one dwelling unit above the base zoning district's maximum density-per-acre calculation without the affordable-housing showing.

The PUD overlay itself requires a minimum tract of two acres, with named exceptions for City Council-initiated rezonings, environmentally sensitive or scenic parcels, and infill sites, and every PUD remains subject to the city's standard platting, site development plan, and building permit process under the Ames Municipal Code.