Homebuilders have long plied their trade in the nation's green-lawned suburbs and exurbs. Now they're turning their gazes to its cities. Spurred by growing consumer interest in city living, top companies like Toll Brothers, Standard Pacific Homes, John Laing Homes, and KB Home have started divisions devoted to urban infill. “An increasingly large [percentage] of the homebuying public are singles, childless couples, [and others who] don't need a big home in the suburbs,” says Jeffrey Gault, AIA, president of KB Home's new KB Urban division.

In addition to demographics, sprawl-induced suburban traffic patterns are also fueling the boom in city living. “Urban might be pushing 15 percent of [John Laing Homes'] total product,” says Phil Simmons, president of the company's year-old Laing Urban division in Culver City, Calif. “It probably will grow every year, because people are tired of the commute.”

The builders know better than to think they can simply transpose their design and construction processes from the burbs to downtown. High-density housing brings its own challenges, which fluctuate from city to city and even neighborhood to neighborhood. “In the case of KB Urban, everything's going to be unique, because every urban site is different,” says Gault, himself a Yale-trained architect. “In the downtown lifestyle, the customer changes depending on the city and the context.”

With the wide-ranging tastes of their baby boomer and echo boomer target markets in mind, many of the new divisions are offering options such as mixed-use buildings, high-rises, and adaptive re-use structures. And while architectural styles will vary according to site and context, look for contemporary design to enter the mix.