In the suburb of Rocklin, outside of Sacramento, Calif., solar-powered home sales are doubling the sales of standard homes according to San Jose-based SunPower Corp., a solar-electric technology manufacturer. Families who purchase the solar-powered homes are reportedly saving up to $120 a month.

The spike in solar-powered home sales in California comes on the heels of a National Association of Home Builders (NAHB) report that nearly 100,000 certified green homes have been built in the U.S. since the mid-1990s. In addition, a recent Roper survey commissioned by the Sharp Electronics Corp., reports that nearly 90 percent of Americans think that solar electricity should be an option for all new-home construction, up significantly from one year ago (79 percent).

By 2011, home builders in California may have to offer solar-power as standard; a proposed bill in the state senate is calling for all home builders to offer solar-power in all new homes built in 2011 and beyond. Lennar Corp. announced in February that all its new homes in the greater San Francisco Bay market would be equipped with a roof-integrated solar-electric system from PowerLight, a subsidiary of SunPower Corp., as a standard feature.

According to SunPower representative Ingrid Ekstrom, since 2005, 1,200 new solar-powered homes have been built in California; more than half use SunPower products. The state's incentives and the pending legislation make offering solar options now a sensible choice for home builders.

"Homeowners value solar-electric systems today because the systems can help significantly reduce electric bills and lower greenhouse gas emissions," said Bill Kelly, general manager, New Homes division, for SunPower Corp. "Builders value the rooftop solar systems because they integrate seamlessly with home design and construction, replacing roofing material and improving solar system roof aesthetics."

Another California builder, The Grupe Co. based in Stockton, includes rooftop solar-electric systems as a standard feature with all of its homes.

"In a sea of widgets that are all the same, we wanted to make our widgets a little different," Mark Fischer, senior vice president of The Grupe Co., told BUILDER Online in a telephone interview Tuesday.

The Grupe Co., according to Fischer, has built roughly 50 single-family homes in 2007; all of which include solar power. In the Rocklin community of Carsten Crossings, the solar-electric-powered homes are selling in the high $400s.

"And the next community [we build], in all likelihood, will be solar," Fischer says.

Learn more about markets featured in this article: San Francisco, CA, San Jose, CA.