Function Follows Form

Controversy has brewed ever since the landmark 1926 U.S. Supreme Court decision of Village of Euclid , Ohio v. Ambler Realty Co., which established the separation of land uses among other restrictions to manage nuisances and protect the public welfare. The resulting "Euclidian" form of zoning has long since been accepted as the standard for regulating development nationwide.
By Bob Sperber, Senior Editor | August 31, 2005

Public Space, Private Problem
Providing Context Across The Transect
Habersham: True to Form

Controversy has brewed ever since the landmark 1926 U.S. Supreme Court decision of Village of Euclid , Ohio v. Ambler Realty Co., which established the separation of land uses among other restrictions to manage nuisances and protect the public welfare. The resulting "Euclidian" form of zoning has long since been accepted as the standard for regulating development nationwide. However it has come under attack as an inadequate tool for dealing with today's seemingly endless growth management conflicts.

Critics of conventional zoning believe the time has passed for strictly promoting the segregation of residential, office, retail, civic and other land uses separated by pedestrian-unfriendly roadways and poorly designed open-space buffers. They claim that this degrades social interaction, quality of life and the natural environment. They say developers should be allowed to create compact, walkable, and diverse mixed-use communities, and that these can benefit both the community and the developer's and builder's bottom line.

Has conventional zoning outlived its usefulness? Proponents of "form-based codes" say yes.

Euclid's Undoing

Considering the changes of the past 80 years and current demands for smart (or at least smarter) growth, it's possible that all of the regulatory tools and tweaks have only complicated matters. These tools and tweaks include conditional use permits, overlay districts, planned unit developments, design guidelines, performance zoning, variances and tax/density bonuses. In contrast, form-based codes are revolutionary; they seek to replace the entire system by streamlining ordinances and shifting away from land use and density as primary regulating factors.

Compared to conventional zoning practice, form-based thinking is not a simple sell to regulators. "It's a whole different approach; you can't just take your zoning and rewrite it into form-based code," says Peter Katz, New Urbanist consultant, professor in practice at Virginia Polytechnic State University and president of the Form-Based-Codes Institute.

One extreme example of regulators' difficulty with change occurred in planning the Cornell community, a 5000-acre plan for an unused airport site outside of Toronto, Ontario, Canada, designed by Miami-based Duany Plater-Zyberk & Co. (DPZ). Here, local plans were subject to approval at the provincial level. "At great expense," Katz says, "the province hired several local planners to re-write DPZ's diagram-rich form-based code into a nearly all-text document."

In the United States, however, the typical local jurisdiction has the legal flexibility to accommodate form-based ordinances. Last July, for example, California Governor Arnold Schwarzenegger signed into law Assembly Bill 1268, which established form-based coding as a legal option for cities to include in their general planning and zoning processes. This followed successful early adoptions by jurisdictions including Petaluma, and the city of Hercules, a fast-growing San Francisco area bedroom community of 23,000.

Under conventional zoning, Stephen Lawton, Hercules' community development director, lacked the design toolkit for traditional neighborhood design and found that "form codes can do that."

Since the 2001 approval of a new form-based code's Regulating Plan drafted by urban design firm Dover, Kohl and Partners, based in Coral Gables, Fla., redevelopment has transformed the 400-acre site of a former dynamite plant. So far, 500 single-family houses have been completed and townhouses with live/work units are on the way. Four builders are involved: DR Horton's Western Pacific Housing unit, William Lyon Homes, John Laing Homes and Taylor-Woodrow homes.

Lawton believes that "form[-based] codes will take over the next generation of planning in California" and affect all developers and builders because they are "increasingly going to have to deal in an environment where municipalities are using form codes to regulate production housing." This, in turn, will affect where and how lots will be available, and who wins approvals. "To the extent that home builders attempt to pass this off as a fad or as a fashion," he adds, "they are not going to be viewed favorably by the municipalities, and it's going to be more expensive to get their projects done."

Streamlined Ordinance

Form-based codes reinforce the notion that a picture is worth a thousand words by putting most of a plan's key dictates into diagrams. Ordinances can be just a few pages for a development that would need dozens of pages in conventional zoning documents. There are only a handful of components in a form-based ordinance:

  • Regulating plan: Maps what goes where — every street, block and building type, or mix of types; defines property lines, required building lines (similar to setbacks) and public spaces — in more detail than conventional zoning maps.
  • Building form standards: Establishes four parameters in cross-sectional drawings, typically on one sheet for each building type: 1) Height: Maximum number of floors; also minimum needed for a proper street wall; 2) Siting: Placement of structures in relation to streets and adjacent lots; front, side and rear building limits; and specs for entrances, parking and yards; 3) Elements: Dimensions for windows, doors, porches, balconies, stoops and so on; 4) Uses: Configuration of specific uses within each building type. Note: Use is not ignored, but dealt with at this secondary level.
  • Thoroughfare standards: Included if streets are not individually designed. Diagrams can define dimensions from travel and parking lanes through sidewalks, medians and planting strips.
  • Landscape standards: Lists accepted tree and groundcover species and location details.
  • Definitions: The glossary helps clarify specific terms.
  • Architectural standards: Optional based on community and developer desire for regulatory controls. May dictate materials and finishes, colors or other controls.

Form-based plans do not stand alone, explains Katz, but are usually embedded in a set of best practices that includes three elements: "a compelling urban design that citizens can get excited about; a public process that gives them a sense of ownership of the plan; and the ordinance itself. They're like three legs of a stool; without one of the legs, it falls down."

Public and Private Sectors Win

For developers and builders, there are pros and cons to working within a form-based regulatory environment. The great deal of detail required in up-front planning may be daunting, even constraining by their fundamentally different nature.

Conventional zoning is proscriptive: it defines what is prohibited rather than what is desired. But by focusing on what builders can't build, critics say, it does not predict with any certainty the appearance of what can or will be built — and invites conflict. In contrast, form-based codes are prescriptive: they define building types, streets and the public realm down to the block-level, whereas conventional zoning stops at the subdivision level and therefore cannot cope with the details of mixed use, varied thoroughfares and so many other factors.

By releasing conventional restrictions on land use and density, many community developers and builders may find greater flexibility to create plans with higher density. Additionally, they may find it easier to "sell" such plans to communities because their easy-to-grasp graphics may present better than words and numbers. If so, form-based codes appear be well-suited to address growth issues such as housing affordability, transit-oriented development, pedestrian-friendly communities, open space preservation — in general, smart growth issues.

Time will tell how this new coding system fares over the established Euclidian order. But this new type of regulation may provide a clearer view of the shape of new development in the earliest stages as well as a clearer path to smarter growth and development.


Public Space, Private Problem

Form-based codes seek to overcome conventional zoning's inability to match building types and street type at the micro level.

A block of small- and medium-sized homes is planned on a side street next to a busy arterial. In this location, conventional zoning rules out multi-family dwellings.

An endcap building, illegal under the current zoning, shields houses and their back yards from the noise, privacy and other impacts of the nearby road. The endcap building can accommodate uses not found in other purely single-family neighborhoods. These may include senior and workforce housing, offices for local businesses and retail stores.

Buildings are designed to match the scale of roads and the surrounding neighborhood.

Providing Context Across The Transect

The conceptual "transect" chart (below) is a kind of Rosetta Stone for many of the concepts in Duany Plater-Zyberk & Co.'s form-based SmartCode. It standardizes land and development rules, zone by zone, from its most rural and undeveloped (T1) to the urban core (T6), with suburbs in the middle. Within a given zone, explains Andres Duany, founding principal of the firm, "each type of structure corresponds with a certain degree of urbanity...the key is to provide urbanism with urban building types, and provide 'ruralism' with rural types." He criticizes conventional zoning for its inability to regulate context, resulting in "clearly inferior" suburban townhouses that have tiny yards and are surrounded by parking lots, particularly lots across front elevations — "but lack any commensurate amenity, such as an increased street life, to compensate for the loss of land.


  • The Form-Based Codes Institute and the Academy for the New Urbanism at Virginia Tech will offer "Form-Based Codes: An Introductory Course," November 3–5, 2005. More information on this and other resources can be found at
  • Duany Plater-Zyberk & Co. has released its SmartCode to the public domain for conditional use. It can be downloaded for free at

Habersham: True to Form

"We don't use the term 'form-based codes' and neither do our builders," says Michael Asnip, vice president of sales and marketing and manager of the builder program for the Habersham community in Beaufort County, S.C. But the developer and builders at Habersham nonetheless operate in an early form-based environment.

When Habersham Land Co. bought the 283-acre parcel from a prior developer in 1997, it was planned unit development zoned for 1,000 residential units including detached to multifamily as well as retail and commercial components. But it was not zoned to allow a Traditional Neighborhood Development (TND). "We wanted to do a TND," says Bob Turner, principal with the developer, but as inherited, he says "the multifamily housing was in the form of one big apartment complex; the single family homes were just arranged in typical cul-de-sac lots; and the commercial was in the form of a strip center." These separate pieces were geographically separate with access along a conventional, spine/collector road.

Duany Plater-Zyberk's Tom Low, director of town planning for Habersham, says the prior developer's zoning would have "privatized the entire waterfront amenity [to] create a group of high-value, 'quick kill' lots but most of the inland lots would be marginalized." Using his firm's form-based code, Low rearranged roads, housing and mixed-use buildings into a more integrated and attractive mixed-use success.

Since 1998, a dozen mostly custom/spec builders have built 200 homes and sold 500 at rates driven steadily up by market demand. "When we started this project we were in the $130,000 range for a 1400-square foot house, a little above the local market," says Turner. "That same house one year later sold for $230,000." Today single-family houses start in the high $300,000s and climb above $1 million; condo flats range from $232,000; and townhouses sell from the high $300,000s to mid $400,000s. These prices are above local norms, following the pattern of coastal, resort communities like Florida's Seaside and Rosemary Beach.

There are likely hundreds of form-based ordinances in existence because, while the term is new, many New Urbanist plans have evolved over two decades to embrace what are now called form-based codes.