MARIN COUNTY -- An online tool to illustrate the rate of housing turnover in Marin County, a collaborative project between the Marin Association of Realtors and Sausalito-based Sunshine Marketing, has won the National Association of Realtors' Game Changer Award.

The online tool, known as the Marin Housing Turnover Index, was recognized in Louisville, Ky., during the annual Association Executive Institute conference. Marin was the only association in California to receive the award and one of 11 nationally recognized for a Game Changer Award.

The national association also gave a $7,000 grant to the Marin association to develop a mobile version of the index. That is expected to be completed in three to five months, according to Marin association CEO Edward Segal.

"We're excited to bring the index to the next level," he said.

First launched in 2008, the index allows visitors to see the expected turnover rate for housing in 14 major housing markets in Marin. It uses data from the U.S. Census Bureau, Marin County Community Development Agency, Bay Area Real Estate Information Services Multiple Listing Service and local sales statistics, with annual data updates from Sunshine Marketing, according to the Marin Association of Realtors.

Reflecting an average turnover rate of 48 years for the county's approximately 110,000 housing units, the index supports the association's position that low-interest loans, rebates and other incentives are more effective in supporting sewer improvements than linking mandates like inspections of sewer laterals and repairs to home sales, according to material from the Marin association.