Planned unit developments, also called planned communities, are a major development type. Originally cluster housing projects with common open space, they can be planned today as infill in downtown areas or as a major master-planned community. They require discretionary review, are often dominant in the zoning process, and present a challenge to the zoning system. A threshold question is how municipalities should zone for planned unit developments, and this Article discusses conditional use, base zone, and rezoning alternatives.  This Article next discusses the zoning review process for these developments, which must operate fairly and produce acceptable decisions. Alternatives that can avoid or supplement discretionary review are considered next, and this Article concludes with a discussion of affordable housing as a social responsibility.    Download the PDF………………