Urbanizing the Suburbs

The Major Development Trend of the Next Generation

Christopher B. Leinberger

The Built Environment

The dawning of the twenty-first century in the United States has seen a structural shift in how the country creates its built environment (defined as infrastructure and real estate). The suburbs have played the major role for a century, but that role is fundamentally changing. Understanding the implications of this structural shift requires the introduction of a few basic concepts.

First, it is important to understand that the built environment takes two basic forms: walkable urban and drivable sub-urban. There are many variations, but broadly speaking there are just these two.

Walkable Urban Development

Walkable urban development is the oldest form employed in building cities and metropolitan areas. This type of development has been the basis for how we have built our cities since Çatalhöyük (in present-day Turkey) was built around 9,500 years ago — the oldest city known to date. Walking is the primary means of getting to and getting around a walkable urban place. The distance that most people feel comfortable walking is about 1,500 to 3,000 feet, which limits the geographic size of a walkable urban place. Research conducted at George Washington University has shown that the average walkable urban place in metropolitan Washington, DC, is 408 acres, about the size of three regional malls, including their parking lots.

Beyond that distance, most people will use another means of transport if it is available. Historically that has meant a horse, a horse-drawn wagon, a bike, public transit (rail or bus), or a car. Within that defined and confined walkable urban place, walking provides access to many if not all everyday needs — shopping, social life, education, civic life, and maybe even work. This mixed-use character means the walkable urban place has a relatively high density; measured by gross floor area ratios (FARs, measuring all land within the area being evaluated, including right of way), between 1.0 and 30. The lowest walkable urban density, such as a small town, could be 1.0, whereas high walkable urban density, like Midtown Manhattan, is about 30 FAR. However, most walkable urban places developed today, particularly those in the suburbs, range between 2.0 and 4.0 FAR, assuming they are employment, destination retail, or civic places (defined later as regionally significant places).

Drivable Sub-urban Development

The second form of built environment is drivable sub-urban development (the hyphen is used to indicate that it is a fundamentally different from and less dense than walkable urban). Drivable sub-urban development segregates the various needs of everyday life one from the other — retail is in a shopping center, work is in a business park, housing is in a subdivision — and the only way to connect these is by car. Walking is generally not a safe or viable option, nor is generally any other form of transportation, such as public transport or biking. The early twentieth-century introduction of cars as a means of transportation was the obvious prerequisite for the drivable sub-urban form of development, enabling a never-before-known alternative form of building and living.

Drivable sub-urban has extremely low-density development compared to walkable urbanism, generally less than 20% of the density as measured by FAR. FAR tends to range between 0.005 and 0.40. Its various land uses — for-sale housing, rental housing, office, industrial, retail, civic, educational, medical, hotel, and more — spread out across vast swaths of land. In other words, sprawl. Most real estate developers and investors, government regulators, and financiers have come to understand this model extremely well, turning it into a successful development formula and economic driver for the midand late twentieth century. Drivable sub-urban development provided a foundation for the economy and "fueled" the dominant industry of the industrial era — the building of automobiles and trucks, including the support industries of road building, finance, insurance, and oil. Drivable sub-urban development was essential to American economic growth in the mid- to late twentieth century.

Economic Functions of the Built Environment

Metropolitan land use supports either regionally significant or local-serving functions.

Regionally Significant Locations

Regionally significant locations, sometimes referred to as submarkets by commercial brokers, are used for the following purposes:

• Concentrations of jobs

• Civic centers

• Institutions of higher education

• Major medical centers

• Regional retail

• One-of-a-kind cultural, entertainment, and sports facilities

Regionally significant land constitutes less than 5% of all metropolitan landmass, according to George Washington University School of Business (GWSB) research, yet it is where the region's wealth is created, where many one-of-a-kind facilities prefer to locate, and where regionally significant retail outlets locate (e.g., malls, concentrations of specialty stores, big box stores, flea markets, and major farmer's markets). GWSB research in metropolitan Boston has shown that regionally significant walkable urban places account for 1.2% of the metro landmass and regionally significant drivable sub-urban locations represent 2.5% of the metro landmass.

Regionally significant places are generally net fiscal contributors for local jurisdictions; that is, the tax revenues they produce (income, sales, property, and other taxes) exceed the costs of the government services they receive (transportation, police, fire, regulatory, legal, etc.). This land use function is...