TAMPA - Though the final quarter of 2008 brought the sound of fewer hammers, a low not heard of in at least 23 years, they haven't fallen silent.

Construction began on 932 single-family homes in the Bay area in the fourth quarter of 2008, according to Houston-based Metrostudy, which tracks new home construction. That's a 32.9 percent decrease from the same quarter of 2007 and the first time in at least 23 years that local quarterly housing starts have fallen below 1,000.

Why are builders building any homes in this economy? If they want to stay in business, they say, they have to keep building at least some.

"Builders have reduced their inventory tremendously, and in some cases builders don't have any inventory," said Joseph Narkiewicz, executive vice president of the Tampa Bay Builders Association. "Even though there may still be discouraging signs in the economy, there's still demand prevalent in the marketplace."

Here's a look at the area's top 10 subdivisions where builders started new homes in the past year, according to Metrostudy. The Tampa division tracks construction in Hillsborough, Pasco, Pinellas, Citrus and Hernando counties.

•K-Bar Ranch (Hillsborough), 165

•FishHawk Ranch (Hillsborough), 146

•South Fork (Hillsborough), 125

•Oak Creek (Hillsborough), 113

•Cypress Creek (Hillsborough), 109

•Concord Station (Pasco), 103

•Ayersworth Glen (Hillsborough), 100

•Summerfield Crossing (Hillsborough), 89

•Trillium (Hernando), 87

•Ventura Bay (Hillsborough), 74

Part of the reason home starts are down is that many builders have been unable to sell the homes they have. There were 2,617 empty new homes sitting on the market in the fourth quarter, compared with 3,496 homes during the same period of 2007. Metrostudy's Tony Polito said it would take about four months to sell those homes at the current pace.

Aside from empty homes, builders are dealing with empty homesites. Some builders overprepared for the housing boom and prepped too many lots. There are 30,640 empty lots in the five-county area, Metrostudy said. That's a 61/2-year inventory.

Reporter Shannon Behnken can be reached at (813) 259-7804.