Urbanism holds promise for reducing energy use

Researchers presented findings at the Congress for the New Urbanism annual conference that show substantial energy savings from higher-density urbanism — greater savings than can be achieved from the US government Energy Star program (see graphs). In a panel on Climate Change and the Built Environment, John Holtzclaw of the Sierra Club and Jennifer Henry of the US Green Building Council reported that density and transit connections could significantly reduce greenhouse gases and the nation’s use of gasoline. “New Urbanism is the magic that can bring about a substantial reduction in the driving that we do,” Holtzclaw said. In a telephone interview with New Urban News, Holtzclaw explained, “it doesn’t require browbeating people into driving less. All you have to do is create the conditions so people can do things by foot — and they will do things by foot.” Density is a proxy for urbanism, Holtzclaw said, because most of the higher-density neighborhoods in the US were built prior to World War II, the watershed event between urban and suburban development. One hopeful conclusion from research by Holtzclaw and others is that even relatively small improvements in density and transit availability — a combination of factors sometimes called location efficiency — yield sizable reductions in auto use. The Potential Energy Savings from Density graph at right shows the steepest curve occuring between the baseline of 3 units per acre and 18 units per acre. Even doubling density to 6 units per acre saves more energy per household than Energy Star, on average. Energy Star sets targets for efficiency of homes — 30 percent higher than the 1993 National Model Energy Code — and household appliances. “You don’t need to despair that you are starting off with low density [in the suburbs],” Holtzclaw explains. “Take a transit node and develop at high density around that node and you see great improvements.” Henry, an urban designer by training who has a key role in the development of LEED standards for Neighborhood Development (LEED-ND), cautions, however, that “it is sometimes easier to achieve green building savings than location efficiency savings, due to the regulatory and cultural barriers” preventing urban forms of development. Related findings: • An average urban household uses 320 million British thermal units (mBTUs) annually, while an average suburban household uses 440 mBTUs (assuming 2.5 people/family). The difference is mostly in transportation and infrastructure. • Access to transit yields significant energy savings, but not as large as increased density. • The economic savings from enhanced location efficiency from 10 years of new construction are about $2.3 trillion, mostly from reduced auto ownership, according to a study by Holtzclaw with David Goldstein and Mary Jean Burer of the Natural Resources Defense Council. • Despite the benefits of location efficiency, it is less recognized than automotive, building, appliance, or power plant efficiency as a way to reduce greenhouse gases and use of fossil fuels. u