Throughout last week's International Builders' Show, rain fell on Las Vegas, an unusual occurrence for the host city that was somehow fitting for the reeling building industry. But the mood inside the Las Vegas Convention Center seemed upbeat, perhaps taking its cue from humorist Dave Barry's keynote address.

The optimism might have been forced, an effort to boost spirits in a glum period for the building industry. After all, attendance was about half what it was during the height of the housing boom; the New American Home 2010 official showcase home wasn't completed due to financing problems; and just days after the end of the Builders' Show, the National Association of Realtors announced that existing-home sales for December 2009 had dropped 17 percent from the month before.

Still, innovative products were on display throughout the hundreds of thousands of square feet of exhibition space, and energy-based technology led the way. Among the leading-edge gear, we saw GE's smart appliances; the Honeywell Wind Turbine WT6500; and Dow Powerhouse Solar Shingles. And while it wasn't technically at the show, the Builder Concept Home 2010 offered a virtual tour of the future of home building.

So as down as things seemed, those innovations and the companies gambling on their success provided me with at least of bit of optimism as I was leaving Las Vegas.

—Daniel DiClerico