An official website of the United States government.

This is not the current EPA website. To navigate to the current EPA website, please go to This website is historical material reflecting the EPA website as it existed on January 19, 2021. This website is no longer updated and links to external websites and some internal pages may not work. More information »

Smart Growth

Codes That Support Smart Growth Development

On this page:


Good codes are the foundation upon which great communities are built. They are the framework that regulates where and what type of development can occur. Codes guide everything from permissible land uses to building densities, locations, and setbacks to street widths and parking requirements.

When done well, codes make it easier for a community to implement its vision. However, when they are out of date or do not line up with the community's vision, codes can actually keep communities from getting the development they want.

For example, conventional zoning practice of the past several decades has separated residential, retail, and office uses. Today, however, this zoning stands in the way of communities that want to create vibrant, walkable neighborhoods that mix these uses and give residents the option to walk to the store, walk to work, or own a home business.

Many applicants to EPA's Smart Growth Implementation Assistance Program request help with updating or revising their codes. In response to this demand, EPA compiled these examples of adopted codes and guidelines from around the United States that support smart growth development. This list is not exhaustive but is a sampling of good, smart growth-supportive codes that communities could use as models to make similar updates to their zoning.

The examples are grouped into seven categories:

  • Unified Development Code — A single document that includes all development-related regulations, including zoning and subdivision regulation.
  • Form-Based Code or SmartCode — A code that outlines a specific urban form rather than zoning by use. Categories are included for form-based codes for area plans and for citywide codes.
  • Transit-Oriented Development — Moderate- to high-density, mixed-use neighborhoods built around transit stops and designed to maximize access to and use of public transportation.
  • Design Guidelines — A set of standards that aims to maintain a certain level of quality and architectural or historic character, addressing features such as building façades, public spaces, or landscaping.
  • Street Design Standards — Guidelines and standards related to travel-lane width, bicycle lanes, on-street parking, medians, sidewalks, landscaping, lighting, crosswalks, pedestrian refuge islands, bulbouts, and accessibility ramps.
  • Zoning Overlay — A set of zoning ordinances, optional or required, specifying land use and/or design standards for a designated portion of the underlying zoning within a defined district; typically used to keep architectural character and urban form consistent, make adjacent uses compatible, or accelerate the conversion of non-conforming land uses.

Other useful resources are Essential Smart Growth Fixes for Urban and Suburban Zoning Codes, which suggests specific code and ordinance fixes that local governments can consider to make development in their communities more environmentally, economically, and socially sustainable, and Essential Smart Growth Fixes for Rural Planning, Zoning, and Development Codes, which offers 10 essential fixes to help rural communities amend their codes, ordinances, and development requirements to promote more sustainable growth.

Top of Page

Unified Development Code

Durham, North Carolina
Population: over 200,000
Unified Development Ordinance Exit— Adopted December 5, 2005
Developed by Duncan Associates

The Unified Development Ordinance implements the comprehensive plan's theme of a tiered system that reflects the different characteristics and priorities found throughout the region. Five "development tiers" were developed: Rural, Suburban, Urban, Compact, and Downtown.

  • Standards for the Rural and Suburban tiers prioritize environmental protection and compatibility with the existing patterns of development in the unincorporated portions of the county.
  • Standards for the Urban, Compact, and Downtown tiers encourage a more diverse pattern, including incentives for mixed-use, pedestrian-scaled development, while incorporating appropriate natural resource protection measures.

Much of the focus in these more urban tiers has been on stimulating and accommodating infill growth and development. This is accomplished through residential density bonuses, commercial and mixed-use height bonuses, reductions or exemptions from parking requirements, modifications to buffer and landscape requirements, and other incentive-based measures.

San Antonio, Texas
Population: over 1,200,000
Unified Development Code Exit— Adopted November 30, 2006
Developed by White and Smith, LLC

This Unified Development Code includes "use patterns" for various forms of smart growth development such as traditional neighborhood development, transit-oriented development, neighborhood centers and conservation subdivisions, new infill development zones, parking caps, and street design and infrastructure options.

The purpose of this code is to consolidate the regulations pertaining to patterns of development in San Antonio. These use patterns reflect either the majority of anticipated permitting activity or the patterns, such as traditional neighborhood development, that the city would like to encourage.

Each section describes the use pattern, the procedure for approval, and the standards relating to approval, with cross-references to other parts of this chapter where needed. The intent is to present a visual, user-friendly overview of the regulations that apply to those types of uses or development styles.

Top of Page

Form-Based Code or SmartCode — Area Plans

Arlington County, Virginia
Population: over 200,000
Columbia Pike Form-Based Codes

Developed by Dover, Kohl & Partners with Ferrell Madden Associates

The form-based code is an optional development approval process designed to help revitalize the Columbia Pike corridor of Arlington County. It uses simple and clear graphic prescriptions and parameters for height, siting, and building elements to address the basic necessities for forming good public space.

The code includes regulating plans, required building lines, parking setbacks, building envelope standards, architectural standards, and streetscape standards. Developers who use the form-based code process receive an expedited approval process and, if developing in a revitalization district, are eligible for county investment.

Knoxville, Tennessee
Population: over 180,000
Form-Based Code (PDF) Exit(124 pp, 1.7 MB, About PDF)— Adopted February 27, 2007
Developed by Chan Krieger Sieniewicz
Vision Plan (PDF) Exit(122 pp, 5.4 MB, About PDF)
Developed by Hargreaves Associates

With the help of many residents, property owners, neighborhood residents, and technical experts, the South Waterfront Vision Plan, Action Plan, Urban Renewal and Redevelopment Plan, and Form-Based Development Code were adopted by the city council in a span of 10 months. The plan for the South Waterfront includes a continuous Riverwalk along the shoreline; several parks and other "windows" to the water; public improvements for streets, sidewalks, bikeways, and parking; and private development that will add new housing units, retail and office space, and entertainment opportunities.

The intent of these codes is to provide a blueprint for future development that allows greater certainty in determining the outcome for growth. The Knoxville South Waterfront Vision Plan represents a possible vision for future growth. These codes are written to tailor future development to achieve this vision.

Peoria, Illinois
Population: over 100,000
Form-Based Code, Phase II of Heart of Peoria Plan Exit (see "Warehouse District") — Adopted June 15, 2007; effective July 15, 2007
Project management by Ferrell Madden Associates LLC
Planning and zoning support by Code Studio

In 2002, the city produced the Heart of Peoria Plan, a vision for reinvigorating 8,000 acres in residential and business districts. A detailed form-based code was created for each of the four main business areas in Peoria, and a more generalized special overlay district was developed for the rest of the "Heart of Peoria," including illustrated, generic building form and architectural standards. The special overlay district is unique in that it is a hybrid of traditional Euclidian and form-based zoning. The most significant community concerns addressed by the code are creation of more walkable commercial areas and retrofitting existing corridors to complement the adjacent neighborhoods.

Top of Page

Form-Based Code or SmartCode — City Wide

Gulfport, Mississippi
Population: over 70,000
SmartCode Exit(32 pp, 7.1 MB, About PDF)— Adopted February 13, 2007
Developed by HDR Town Planning

As part of ongoing work to support the recovery of the Gulf Coast through the Mississippi Renewal Forum, the city of Gulfport worked with New Urbanist designers and planners to establish a new vision for growth and development. The SmartCode was the result of two charrettes.

  • The first was coordinated by the Mississippi Renewal Forum, October 12-18, 2005, and focused on 11 communities along the gulf.
  • The mayor and city council asked HDR to conduct a second charrette, which was held in February 2006, to focus on writing the SmartCode.

One of the overall recommendations was to adopt the SmartCode as an overlay throughout the city of Gulfport, used in conjunction with existing codes. The team recommended that the SmartCode be mandatory in the downtown area south of the CSX tracks.

Leander, Texas Population: 8,000
SmartCode Exit(79 pp, 10.4 MB, About PDF) — Adopted September 22, 2005
Customized by Gateway Planning Group and PlaceMakers

City officials recognized the impact of growth pressures on its community and the opportunity to capitalize on proposed increased investment in transportation planning. To respond to the situation, Leander worked with consultants to establish clear directives for land use planning to help guide new development into existing and planning transit corridors.

This process involved investigating best practices of transit-oriented development (TOD) and code reform that result in compact, walkable, mixed-use neighborhoods. Officials determined that the most effective strategy would be to update the city's zoning code as a SmartCode.

This SmartCode, which serves as a Unified Development Ordinance, applies in full force and effect only within the boundaries of the Transit-Oriented Development Sector. The Community Plan created under this code defines the TOD Sector as represented in the TOD Transect Map, as amended. The code and the transect map are in accord with the city's comprehensive plan and ordinances.

Montgomery, Alabama
Population: over 200,000
Traditional Neighborhood Development Overlay SmartCode Exit — Adopted January 2006; amended May 2007
Developed by Dover, Kohl & Partners

The purpose of this SmartCode is to create a community and region that adheres to the general principles of the transect.

  • The region should maintain its natural infrastructure by respecting watersheds, woodlands, and other natural features.
  • Growth strategies should encourage infill and redevelopment. This development should be contiguous with existing urban areas and follow a pattern of traditional villages and towns that are highlighted by walkable blocks, a range of housing opportunities, and transportation options.
  • Communities should be compact, with an emphasis on accommodating everyday activities a short walk from residences.
  • Land uses should be organized to support transit, civic uses including public open spaces should be embedded in neighborhoods, and schools should be neighborhood oriented.
  • The blocks and buildings should accommodate automobiles while serving pedestrians.
  • A sense of local place should be established through materials, architecture, and layout of uses.

The SmartCode has been calibrated to fit the local context of Montgomery and its social, political, and built environment.

St. Lucie County, Florida
Population: over 200,000
Form-Based Code Exit — Adopted May 30, 2006
Developed by Treasure Coast Regional Planning Council with Dover, Kohl & Partners and Spikowski Planning Associates

This form-based code was adopted for a 28-square-mile area just beyond the urban fringe of the city of Fort Pierce in northern St. Lucie County, Florida. It was created to implement the "Towns, Villages, and Countryside" (TVC) master plan prepared for St. Lucie County by the Treasure Coast Regional Planning Council in 2004. The TVC plan combines agricultural preservation and limited development. Existing development rights can be exercised only by concentrating them in new town or villages, each to be surrounded by continued agricultural activity.

Unlike most form-based codes, it is being adopted before the physical design of individual villages. The code provides explicit standards for each village, including minimum percentages of the land that will remain as "countryside" and assignment of the developable portion of each village into zones based on an urban-to-rural transect. A regulating plan for each village must identify specific transect zones and assign allowable street types and lot types in accordance with standards in the code. Each regulating plan is subject to approval by the Board of County Commissioners through a planned unit development-like rezoning process.

Top of Page

Transit-Oriented Development

Contra Costa County, California
Population: over 1,000,000
Pleasant Hill BART Station Property Code — Adopted November 5, 2002
Explanation of Regulating Plan & Building Envelope Standards Exit(26 pp, 583 K, About PDF)
Regulating Plan Exit(1 pp, 168 K, About PDF)
Architectural Standards Exit(21 pp, 2.7 MB, About PDF)
Developed by Geoffrey Ferrell Associates
Master plan by Lennertz Coyle and Associates (now HDR Town Planning)

The code contains definitions, the BART Station Property regulating plan, and the building envelope standards. There is also an accompanying architectural standards document. These codes were adopted as part of a planned unit development rezoning and preliminary development plan.

Palo Alto, California
Population: over 60,000
Pedestrian & TOD Mixed Use Context-Based Design Guidelines; Zoning Ordinance Update Exit — Adopted in sections beginning in 2005
Developed by Van Meter, Williams, and Pollack and Urbsworks, Inc.

The city of Palo Alto updated its zoning ordinance to reflect its updated comprehensive plan. The first phase analyzed existing standards through the development of prototypical designs for a variety of site and development contexts. Context-based design guidelines incorporate innovative zoning techniques and a form-based, design-oriented approach through the development of building and site planning design prototypes. The context-based design guidelines for the pedestrian- and transit-oriented overlay district for California Avenue and the mixed-use zoning regulations provide developers and the city with key guidelines to ensure development meets the city's needs.

Top of Page

Design Guidelines

Mountain View, California
Population: over 70,000
Residential Guidelines Exit (see Rowhouse Design Guidelines and R4 Multifamily Standards) — Adopted March 2005
Developed by Van Meter, Williams, and Pollack

The regulations and guidelines establish how streets, pathways, and open spaces work together to organize development and provide guidance for character-defining architectural and site planning elements. The rowhouse design guidelines describe how new rowhouse development should be designed to create desirable residential developments and ensure a seamless integration with existing neighborhoods. The R4 zone is intended to encourage high-density residential development in standard residential zones, where previously such development was allowed only in certain Precise Plan areas.

Top of Page

Street Design Standards

Aurora, Colorado
Population: over 300,000
Urban Street Standards in Transit Oriented Developments and Urban Centers Exit (26 pp, 583 K, About PDF) — Adopted May 14, 2007; effective June 23, 2007
Developed by Fehr and Peers

These standards will be applied to create a safe, comfortable, pleasant, and pedestrian-friendly multi-modal travel environment that helps the creation of vibrant civic places and economic vitality in transit-oriented developments and urban centers. The Aurora Comprehensive Plan identifies various TOD sites and urban centers throughout the city. The comprehensive plan includes a recommendation to "develop urban street standards for use in emerging areas of the city such as urban centers and transit oriented development sites."

San Diego, California
Population: over 1,200,000
Transit Area Overlay (PDF) and Urban Village Overlay (PDF) Exit — Added December 9, 1997; effective January 1, 2000
Developed by the city of San Diego

These sections of the city of San Diego's Municipal Code outline parking standards in areas of the city where transit is encouraged.

  • The intent of the transit overlay zone is to identify areas with reduced parking demand and to lower off-street parking requirements accordingly.
  • The intent of the urban village overlay is to create a mix of land uses in a compact pattern that will reduce dependency on the automobile, improve air quality, and promote attractive, vibrant neighborhoods.

Urban villages are characterized by interconnected streets, building entries along the street, and architectural features and outdoor activities that encourage pedestrian activity and transit accessibility. These regulations are intended to be used in conjunction with the Transit-Oriented Development Design Guidelines of the Land Development Manual and the applicable land use plan.

Top of Page

Zoning Overlay

Nashville, Tennessee
Population: over 500,000
Metro Zoning Code, Urban Zoning Overlay Exit— Adopted October 18, 2006
Developed by the city of Nashville Planning Department, published through Municode

The Urban Zoning Overlay (UZO) district is a special type of zoning district. Overlay zoning districts like the UZO are tools for dealing with special situations or accomplishing special goals. They can be placed "over" the base zoning for an area to alter some of the regulations. The UZO district was created to better regulate development in the older urban areas of Nashville. Most of the development in the UZO area was built before World War II.

The current zoning code was designed for a newer suburban environment with a different development pattern. For example, in the UZO area, commercial buildings are often built right up to the edge of the sidewalk. In the suburbs, they are further back from the street. Lots in the UZO area are generally smaller than they are in the suburbs, and buildings are usually closer together. Most neighborhoods in the UZO area have alleys, with garages behind houses instead of attached to them. Until the UZO was developed, the zoning for the UZO area did not fit this development pattern.

Top of Page