Types of Zoning Codes

New approaches to zoning matters are emerging and evolving. What follows is a brief description of the four basic types of zoning codes: Euclidean, Form-Based, Incentive and Performance.

Euclidean Zoning

The most common and most traditional approach to zoning is called Euclidean zoning. It is named after the town of Euclid, Ohio. A landowner in Euclid, Ohio challenged the city's zoning code. The case wound its way up to the U.S. Supreme Court which upheld the municipality's ordinance. The case was decided in 1926, and the term "Euclidean zoning" emerged and influenced the content and design of zoning codes across the country for decades.

Euclidean zoning regulates development through land use classifications and dimensional standards. Typical land use classifications are single-family residential, multi-family residential, commercial, institutional, industrial and recreational. Each land use must comply with dimensional standards that regulate the height, bulk and area of structures. These dimensional standards typically take the form of setbacks, sideyards, height limits, minimum lot sizes, and lot coverage limits.

The traditional planning goals associated with Euclidean zoning are providing for orderly growth, preventing overcrowding of land and people, alleviating congestion, and separating incompatible uses (such as insuring that a noisy factory cannot be built near a residential neighborhood).

Euclidean zoning has come under scrutiny and criticism due to its lack of flexibility and somewhat outdated planning theory. Philadelphia's zoning code is a Euclidean code.

Form-Based Codes

A form-based code places more emphasis on regulating the form and scale of buildings and their placement along and within public spaces (such as sidewalks, street trees, street furniture). Some of the urban planning goals of form-based codes include curbing urban sprawl, promoting pedestrian safety, and preserving the fabric of historic neighborhoods.

The following description appears on the Form-Based Codes Institute website:

Form-based codes address the relationship between building facades and the public realm, the form and mass of buildings in relation to one another, and the scale and types of streets and blocks. The regulations and standards in form-based codes, presented in both diagrams and words, are keyed to a regulating plan that designates the appropriate form and scale (and therefore, character) of development rather than only distinctions in land-use types.

The City of Miami has a "floating-zone" form-based zoning code, and Denver is moving in this direction. Form-based codes are very new, and have not been utilized yet in any large, old industrial city. Depending upon the quality of the code and its diagrams, form-based codes can be difficult to interpret and administer.

To learn more about form-based codes, go to:

• http://www.formbasedcodes.org/index.html
• http://en.wikipedia.org/wiki/Form-based_codes

Incentive Zoning

Incentive zoning, as its name implies, offers a reward (usually in the form of increased density) to a developer who does something "extra" that is in the community's interest (such as more open space) or promotes a public goal (such as affordable housing).

The Smart Growth Resource Library defines incentive zoning as follows:

Incentive zoning allows a developer to build a larger, higher-density project than would be permitted under existing zoning. In exchange, the developer provides something that is in the community's interest that would not otherwise be required (e.g., open space, plazas, arcades, etc.). The common types of community benefits or amenities for which state and local governments have devised incentive programs are urban design, human services (including affordable housing), and transit access.

Incentive zoning has its origins in New York City and Chicago. It has become increasingly common over the past 20 years. The terms "density bonuses" or "community benefits" are related terms and are often used when discussing incentive zoning.

Incentive zoning allows for a high degree of flexibility, but it can be complex to administer.

Performance Zoning

A key goal of zoning codes is to limit conflicting and incompatible uses. Traditional Euclidean zoning does this by regulating land use and bulk. Performance zoning, however, regulates the effects or impact of land uses through performance standards. Performance standards usually concern traffic flow, density, noise and access to light and air. Developers can build almost any building that meets the performance standards for that district. Therefore, performance zoning allows for a great deal of flexibility. This level of flexibility makes it a very useful tool, but also makes it difficult to administer.

Currently, no large city has a zoning code based completely on performance zoning. Chicago has used a hybrid approach for its manufacturing districts, using performance standards in addition to Euclidean zoning.

More information about Chicago's manufacturing districts can be found in the publication Revise, Recreate, Rezone: A Neighborhood Guide to Zoning prepared by the Metropolitan Planning Council. Go to http://www.metroplanning.org/zoningGuide/index.html