Long before the bombing of New York last September, builders had begun to suspect that Hollywood's depiction of America might be a hoax. In that reality, the president himself beats up hijackers; starter mansions have become the shelter du jour; and young, middle-class white people represent our demographic future.

But as the latest U.S. census results come under closer scrutiny, it becomes clear that Hollywood assumptions range from the half-true (homes are getting larger, but the need for affordable housing is epidemic), to grossly misleading (in the next 10 years, minorities may account for a net two-thirds of all new households formed in the United States).

"Stereotypes are changing," notes William Frey, a demographer with the Milken Institute in Santa Monica, Calif. "In California, for example, 45 percent of the kids who live in poverty are in two-parent households."

Among the catalysts of this change: massive international immigration, elderly "yuppie" boomers, and revitalized cities.

In the new America, says Frey, "aging boomers and new immigrants are creating regional demographic divisions that will be just as important as old distinctions like city vs. suburb or rural vs. urban."

The effects of these forces sometimes have far reaching ramifications--from the "cappuccino" gentrification of the rural West--to the so-called boomburbs around metro areas like Miami and Dallas. Urban areas once nearly abandoned are rising from the decay and neglect of decades as demand for higher density living increases. These attitude changes can be best understood on a regional scale, notes Frey.

"Melting-pot regions will become increasingly younger, multi-ethnic, and culturally vibrant," he asserts. "They include California, Texas, southern Florida, the eastern seaboard, and Chicago. Heartland regions, to the contrary, will become older, more staid, and less ethnically diverse."

Families, too, are changing. The number of married people with children has leveled off at less than a quarter of the population. Single parents now constitute an enormous, relatively unrecognized constituency. And no one can ignore the graying populace, which already represents a vast and vocal block.

Will builders be ready?

"One thing builders need to do right now is to put the demographics of diversity at the forefront of their minds," asserts Frey. "The traditional middle-class market is going to run dry soon, and if they don't believe that, all they have to do is look at the numbers."

Good idea. That's exactly what we've done, in this special BUILDER report on the metamorphosis of the U.S. population. For your edification, here's a compilation of some of the facts, figures, and percentages most likely to affect your livelihood in the years to come.

The Immigrant Rush: Revolving Doors Affluent Invaders: The New West The Age Factor: Shades of Gray Inner Sanctums: Downtown Rebound Sea Change?: Sellers Beware

Learn more about markets featured in this article: Los Angeles, CA.