Adriene Hill: New-home sales for the month of November are due this morning. The market’s been improving — at least marginally — over the past few months. But 2011’s likely to go down as one of the worst sales years on record.

Sarah Gardner reports from Chino Hills, Calif., where one home builder is trying to innovate its way out of the housing doldrums.

Sarah Gardner: Greg McGuff is in a good mood these days.  In fact, he’s downright giddy.

Greg McGuff:  I’ve been in homebuilding for 16 years and everyone I know who’s been in longer, we have never seen a product this exciting.

McGuff is a division president for Lennar Homes, one of the largest builders of new houses in the country. Lennar’s testing out a new home design it calls NextGen. It’s aimed at the nearly 20 percent of us now living with aging parents, boomerang kids or other assorted friends and family.

McGuff:  We call it a home within a home. 

Picture a modern, two-story home, 3,300 square feet. Six hundred of that is a private suite with its own entrance, but set back a ways so it doesn’t look like a duplex.

McGuff: When you walk into the NextGen suite you have your own living room, you have your own private bedroom,  your own private bath, your own kitchenette area.

At a recent open house in Chino, 40 miles east of L.A., lookie loos and potential buyers like Mike and Karen Phillips get the tour.  They’ve got a 24-year-old son still living under their roof.

Karen Phillips:  It would be nice for him to actually have a kitchen area, a garage space, things like that,  that he would feel more independent.

And spare Karen those 2 a.m. dinners he makes in her kitchen after a late night. Lennar hopes NextGen will spark some badly-needed sales in a lackluster housing market. But the company’s hedging its bets, rolling out just a few at a time in large master planned communities in California, Nevada and Arizona.

And smartly, says consultant Patrick Duffy, only in cities with lots of immigrants.

Patrick Duffy: Specifically Asian, Hispanic groups, where it’s seen as a benefit to live with your family.

But Duffy suspects in this lousy economy, that idea may not remain a minority opinion.

In Chino, Calif., I’m Sarah Gardner for Marketplace.