Changing Skyline: Suburbia's outer ring losing shine, some economists say

I set out the other day to find the outer edge of the Philadelphia suburbs and ended up in a Chester County subdivision called Oakcrest. Located 45 miles west of Center City, just outside Coatesville, Oakcrest has a network of immaculately paved streets, glossy utility boxes, and an active sales office. What it does not have is a lot of houses.

Oakcrest was laid out for 169 single-family homes, but only 32 were completed when the builder went belly up after the 2007 housing crash. The result is a kind of zombie subdivision: Oakcrest is outfitted with all the necessary infrastructure, but it lacks the pulse of human life. Numbered signs resembling grave markers have been jammed into the earth to identify the available house lots. Since being taken over by a new developer last year, only three more Oakcrest houses have found buyers.

Is Oakcrest a sign that the region's suburban sprawl has finally reached its limit, or is it just a casualty of the housing bust?

Back then, experts maintained that the relentless march of suburbia would resume just as soon as the overstock of houses was exhausted. But five years after the market seized up, planners and economists aren't so sure, and they've begun to ponder a previously unthinkable notion: The heyday of the suburbs may be over.

Not for every suburb, of course. The original, close-in, commuter suburbs, such as those on the Main Line, aren't likely to lose their luster anytime soon. The next ring of suburbs can probably survive, too, if they make some structural adjustments, such as adding more townhouses and apartments. It's low-density, fringe exurbs like Oakcrest, beyond the orbital pull of the big city, that may not have much of a future.

The demise of the Great American Exurb was heralded this fall in a New York Times op-ed by University of Michigan planning professor Christopher B. Leinberger. He argues that "a profound structural shift" has begun to reverse the residential patterns set in the 1950s. Cities are rising, while suburbs are going into decline. His views are shared by many developers, who are shifting to townhouse and apartment projects.