Traditional Zoning Can't Meet the Challenge of Modern Development

In contrast, form-based codes, while allowing great freedom in determining uses, establish definitive criteria for essential urban and architectural design elements: street network and block patterns; layout and configuration of public open space for parks and plazas; disposition of buildings, drives and parking; and height, volume and even facade design requirements for both general building types and special buildings -- civic and institutional structures, schools, retail shopping, entertainment and sports venues. Unlike conventional zoning, they seek to erase rather than reinforce boundaries.

Form-based codes also regulate density, but they specify minimum as well as maximum densities and include reasonable provisions for increasing density where justifiable, such as near public transit stops.

Regrettably, implementing form-based zoning is not easy.

First, because long-standing zoning ordinances create vested property rights and values, any changes must take those rights and values into account and, to a reasonable extent, preserve them. Otherwise, changes can be confiscatory and unconstitutional. Yet preservation of the status quo, based on zoning maps drawn many decades ago, can seriously conflict with current planning and development aspirations.

Second, because land-use planning precedes land-use regulation, form-based codes must be based on well-researched, comprehensive master plans. Without such plans, there is no rational way to establish and legally justify form-based urban design. However, many jurisdictions have neither the resources nor the planning staff necessary.

Third, because some state charters and statutes -- for example, in Virginia, Pennsylvania and Texas -- limit local government's ability to tinker with land-use regulation and thus infringe on property rights, imposing requirements beyond those already in place can require state legislative approval.

Finally, because the concept of form-based codes is unfamiliar, a city or county cannot enact such a measure without first helping residents understand the concept. That requires diligent explanation, illustration and demonstration, including comparing alternative development scenarios that show what conventional zoning yields with what results from form-based zoning.

Probably the most feasible strategy is to make new plans for particular sectors within a jurisdiction where intense growth is desired or is likely to occur as a result of development trends, zoning or both. Form-based design and development criteria can then be applied as a zoning overlay, without rescinding existing ordinances or drawing totally new zoning maps.

A good example of that approach is the Carlyle neighborhood in Alexandria, a multi-block development south of Duke Street and west of Old Town. Now nearing completion after nearly 15 years of construction, Carlyle's overall urban pattern and architectural character are governed by a detailed master plan and form-based design criteria. The Alexandria City Council approved them as a special-purpose zoning overlay before a single spade of dirt was turned.

Form-based design regulations, rather than old-fashioned zoning, are shaping the redevelopment of the centers of Silver Spring and Rockville.

Fortunately, city and county planning officials throughout the United States, along with urban designers and architects, are increasingly acquainted with form-based codes. At the same time, there are more examples of new development shaped by form-based regulations instead of conventional zoning.

Thus, despite impediments, persuading constituents to embrace form-based codes should get easier.

Roger K. Lewis is a practicing architect and a professor of architecture at the University of Maryland.