Even in Texas, the land of go big or go home, they’re downsizing.

Diane Cheatham, owner of Urban Edge Developers in Dallas, said today, the average size of home they’re building is 2,200 square feet, down from 2,500 in 2005 — which was considered small for Dallas back then.

She said the trend there is more toward building green homes instead of big homes. Right now, they’re building a 1,200-square-foot uber-green home for a couple that’s downsizing from 3,000-square feet, Cheatham explained.

1,200? Some of the hair in Texas is bigger than that!

“We’ve never built one that small,” Cheatham confessed, but added: “I think that’s just a good example of the trend right now.”

For a little historical context, 1,200 square feet was the average home size in America in the 1960s. That grew to 1,710 square feet in the 1980s and 2,330 square feet in the 2000s.

What’s more, many in the real-estate business say they think this trend of downsizing, or “right-sizing,” as Flint likes to call it, is here to stay.

“This is absolutely a long-term effect,” he said. “Think of families with small children who’ve been foreclosed upon … When these teenagers are in a position to buy a home, they won’t want to go through these experiences they saw their parents go through.”

Of course, the question becomes, what do we do with all these McMansions that have already been built?

It's tempting to make jokes about what you might do with a former McMansion but with crime on the rise in neighborhoods littered with abandoned McMansions, Christopher Leinberger, in an article for the Atlantic, asked a sobering question: Is this the next slum?

Luckily, people are starting to get creative: A film collective in Seattle has taken over a 10,000-square foot McMansion there, using it for both living and work space. They turned a wine closet into an editing room and tossed a green screen in the garage. And in a suburb of San Diego, one couple turned a former McMansion into a home for autistic adults.

The demise of the McMansion has stirred a growing chorus of murmurs in the real-estate community about the possibility that it may force a dramatic redesign of the suburban McMansion tracts into mini-towns of their own, turning these icons of excess into more practical spaces like offices, banks, grocery stores and movie theaters.

Though, given some of the poor quality of materials and craftsmanship, it begs the question, would it be better to just tear them all down and start from scratch?

Have some thoughts on what to do with former McMansions? Drop a comment in the box below. Or, email .

More from the Pony Blog at ponyblog.cnbc.com.