Despite news reports touting a trend toward smaller floor plans and more efficient use of space, the size of the average single-family U.S. home started has gone up since 2009, the National Association of Home Builders says. In the first half of 2011, that number climbed to 2,522 square feet, slightly above 2007's peak of 2,504 square feet. But don't bet on a return to McMansions just yet. Skeptics will suggest the numbers of recent single-family starts may be skewed by the fact that many people who might have bought smaller starter homes in years past have ended up recently buying multifamily units instead. Those units don't count in the single-family starts column, and thus don't show up in NAHB's chart.