Form Follows Function? How America Zones

Abstract

For nearly a hundred years, most urban development control in the United States has been exercised through functional zoning—a system that divides cities into blocks of land and assigns a functional class to each (e.g. residential, business, industrial). Over the last few decades, however, much attention has been focused on the need to reform the system. Reform advocates have criticized conventional zoning on economic, social and environmental grounds and have proposed a number of alternatives, including performance zoning and form-based zoning. A literature review may leave one with the impression that the old system has reached its expiration date and its alternatives are gaining speed. But research has yet to systematically examine the state of US zoning in practice . Has zoning practice caught up with emerging concepts in planning theory regarding the importance of mixed use in cities? This article attempts to help answer this question by studying zoning practice in 25 of America's largest cities. First, it introduces aggregate data on the 25 selected cities and then it discusses four case studies in greater depth (Cleveland, Fort Worth, Denver and Las Vegas). Based on the findings, the article argues that although several attempts to reform the zoning system are underway in practice, the system's core premises are yet to be fundamentally changed.

Acknowledgements

The author thanks the Institute of Society, Culture and the Environment (ISCE) at Virginia Tech for funding this research. Special thanks to ISCE's Director, Professor Karen Roberto. The author also expresses her gratitude to Jesse Richardson, Julie Steiff, Vincent Nadin, Robert Shipley, and the PPR's reviewers for their very helpful comments on earlier drafts of this article. Shraddha Nadkarni should be credited with collecting much of the data that was necessary for the article in her capacity as a research assistant.

Notes

 1. A database search of the terms ‘mixed’, ‘use’ and ‘planning’ yields 45 articles, most of them in US journals published after 2000.

 2. In a study of locales in Ohio, Hirt (2007b) for example, found that communities have mixed-use districts on paper, but these districts may be surprising restrictive (e.g. they allow a mixture of housing types, but ban all commerce).

 3. Where empirical research has been conducted, though, this appears to be case. See, for example, Hirt (2007b), who compared Cleveland, Ohio, with its suburbs. Cleveland has a much more pro-mixed-use zoning code.

 4. In this article, however, I mostly focus on what is allowed and what is prohibited in residential and commercial districts. Public uses (e.g. libraries, museums) are often allowed in residential and commercial districts rather than in districts explicitly designated as public. Agricultural districts typically allow certain residential uses as well.

 5. Not everyone agrees with these arguments. In this article, I do not aim to necessarily advocate mixed use. I only outline the drawbacks of traditional zoning in order to explain why its alternatives have emerged and subsequently evaluate the extent to which they have been adopted in practice.

 6. PUD can be tied to preselected tracts of land much as a traditional zoning district or can be used as overlay or floating zones (i.e. developers may propose PUD upon their own initiative in an area of town which is otherwise covered by traditional zoning).

 7. However, educational and cultural institutions are routinely permitted.

 8. New York's code is also unique in that it has commercial zones ‘nested’ within residential districts.

 9. These are: One-Family (A-2.5A), One-Family (A-43), One-Family (A-21), One-Family (A-10), One-Family (A-7.5), One-Family (A-5), One-Family Restricted (AR), Two-Family (B), Zero Lot Line/Cluster (R1), Townhouse/Cluster (R2), Low Density Multi-family (CR), Medium Density Multi-family (C), High Density Multi-family (D) and Urban Residential Districts (UR). The ‘A-2.5’ notation means a minimum lot size requirement of 2.5 acres. The ‘A-43’ means a minimum lot size requirement of 43, 560 square feet, etc.

10. In a sense, one could say the US PUD is a mini-version of the English discretionary system.