What’s the real relationship between housing density and quality of life? Will denser zoning ease traffic congestion? Result in high crime rates? Cause an increase in pollution? The answers may surprise you—and your fiercest opponents.
As a builder, you probably like the idea of higher-density zoning, of putting more units on every acre of precious land. At the very least, you would like to have the freedom to make that choice. But pick up a newspaper in any growing region of the country and you’re likely to read about public opposition to additional density. Behind the NIMBYism: deep-rooted stereotypes that link denser living with crumbling public projects.
But the reality of what happens when people live in closer proximity is far more complex and variable. A body of new research shows that density impacts a region differently, based on other choices made by homeowners. It is neither a quick fix for sprawl, nor a Pandora’s Box that will unleash drugs and crime on a neighborhood.
The bottom line: Density is a mixed bag. Its social impact depends largely on the needs and expectations of buyers. But don’t take our word for it. Here’s what the research and experts on the topic have to say in response to four common assumptions about the impacts of increased density.
Assumption 1: Denser living leads to higher crime rates, drug use, and general moral malaise. “There’s no evidence of truth in that,” says Genevieve Giuliano, a professor at the University of Southern California’s (USC) School of Policy, Planning, and Development in Los Angeles. “In places that are growing fast, it’s almost inevitable that density is increasing, but people still have many options.”
Reporting in Scientific American, researchers suggest that the stereotype that associates violent crime with population density is based on completely spurious research conducted decades ago. In fact, they note, such research examined laboratory rats and primates, not people, and the results should never have been used to predict human behavior.
The same study points out that population density in the Netherlands, for example, is 13 times higher than the United States, yet its homicide rate is eight times lower.
Even when the researchers factored in the higher population of cities versus rural living, they found no significant correlation with higher crime rates.
In fact, they found that humans have an uncanny ability to deal with crowded conditions, yet remain relatively civil to one another. “Our research leads us to conclude that we come from a long lineage of social animals capable of flexibly adjusting to all kinds of conditions, including unnatural ones such as crowded pens and city streets.” They do offer one caveat: When the variable of limited resources (such as food) is entered into a crowded population, criminal behavior is more likely—and all bets are off.
Assumption 2: Cities are dying. People aren’t interested in urban living anymore. The American Dream of detached homeownership remains unchallenged. “Density doesn’t have to be an ugly word,” asserts Rick Emsiek, a partner with the architectural firm McFarland, Vasquez, Emsiek & Partners in Irvine, Calif. “I think the number of people willing to look at [high-density housing] is growing. Commutes have become more and more arduous. People are asking themselves, “Do I really need a third of an acre and a 4,500-square-foot house?”
At the same time, consumers seem to be adjusting to having less outdoor space and are more willing to accept zero-lot homes. According to the NAHB, the average lot size for new homes has dropped from 9,750 square feet in 1992 to 8,612 square feet last year, while floor space increased slightly.
But, as Giuliano points out, people don’t need to live in a city to thrive in the United States. Ultimately, their decision to accept or reject greater density is rooted in the tremendous freedom they have to choose.
“We live in a world where employment is decentralized, so it’s a question of choice. There are a lot of people who would say that quality of life is lower in the suburbs than in the city. Give me a street with some activity on it, and that’s where I want to be.”
Assumption 3: Higher-density living will reduce transportation problems such as traffic congestion and air pollution, by increasing use of public transportation and reducing travel by car. At USC, Giuliano has just finished a major study on how population density impacts transportation use.
She says that while denser living often does correlate with less travel, the reasons may have as much to do with personal wealth and retail decentralization as with occupants per acre.
“In the United States, most people who live in high densities generally have a lower income,” Giuliano says. “They’re often elderly. So they’re naturally traveling less. They don’t have the resources of people in the suburbs.
“People also get around differently, even within a neighborhood,” she says. “The evidence shows that not everyone who lives in a traditional neighborhood is going to walk more.”
Giuliano also suggests that sprawling retail patterns in the United States weaken the transportation benefits of increased residential density. She points out that in Europe the situation is much different. In Britain, for example, rural dwellers and city dwellers travel about the same amount.
“Almost anywhere you go in England, local shops and services are very accessible,” she explains, “so people don’t have to go far. All of their non-work activities are closer.
“Once you get to many-thousand-square-foot grocery stores and Wal-Marts, you have a different landscape,” she continues. “It’s the same for medical care. All kinds of activities have changed that way.”
Assumption 4: Most people want to live in single-family homes. Those same people will see denser, multifamily living as a transitory step toward detached homeownership. “That may have been true 20 years ago, but it’s simply not true any more,” says Rick Emsiek. “Historically, density was marketed toward people who couldn’t afford a house. Not anymore.”
Emsiek notes that he has seen a quantum shift in the way people look at lofts, condominiums, apartments, and townhouses in his region of California. They want to keep them for life. He attributes much of that mental shift to better design.
“We do a lot of different versions of lofts and condominiums,” he says. “Some are stacked, some are wide open, often in the same building.”
Whatever the root causes, the sales record of units his firm has designed supports his case. Clients typically include a mix of young couples, retired people, and singles—all living under the same roof.
“Are there sacrifices? Yes,” Emsiek says. “But there are all sorts of benefits. You can give them privacy, exciting floor plans, ease of access, and the way of life they want.”
- “Another look at travel patterns and urban form: the U.S. and Great Britain,” Carfax Publishing Co., part of the Taylor & Francis Group, October 2003, Vol. 40, No.11, pp. 2295-2312, by G. Giuliano.
- “Mental Life and the Metropolis in Suburban America: The Psychological Correlates of Metropolitan Place Characteristics,” Urban Affairs Review, November 2003, Vol. 39, No. 2, pp. 228-253(26), by J.E. Oliver
- “Coping with Crowding,” Scientific American, May 2000, Vol. 282, Issue 5, by F.D.M. de Waal, F. Aureli, P.G. Judge