A sense of place
"All Americans have a fundamental need for a sense of orientation, for a sense of place," McMahon said.
This sense of place, the qualities that distinguish one hometown from another, is what makes our surroundings worth caring about, McMahon said.
"You actually have to work to keep the quaint in the town and the scenic in the landscape," he told the group.
Even Hagerstown, which has numerous preservation projects set in motion, could afford to do more, McMahon said.
"Downtown Hagerstown looks great, but think about the gateway on U.S. 40," he said. "A bad first impression is hard to change."
McMahon said a number of factors drive the need for change in the way we think about development, including global warming and higher oil prices. Historic preservation goes hand-in-hand with these goals, because developing historic downtown areas limits driving distances and lessens the need for new construction.
"The greenest building is often an existing building," McMahon said. "The most fuel-efficient car is the one you don't have to drive."
McMahon encouraged planners and developers to work to bring retail and restaurant chains into historic buildings instead of constructing big-box stores and cookie-cutter fast-food joints.
"Our communities look like they're being built with Legos; interchangeable parts," he said. "Communities that are smart enough, savvy enough, say 'I want something that fits in my community. I don't want the off-the-shelf model.'"
In addition, it's important for communities to establish areas that will be off-limits for development, he said.
Other tips included embracing mixed-use development, enhancing public transportation, encouraging the planting of trees and keeping streets narrow.
McMahon said these changes are necessary for the future we face.
"You can wish away growth all you want, but you know, people are coming to the United States," he said. "We are a growing country and ... we're sleepwalking our way into the future. We have no real plan to accommodate all this growth."