Home for sale in Round Rock, Williamson County July 2015 home sales in Williamson County increased by nearly 12 percent from 2014.[/caption] July home sales in Williamson County increased by nearly 12 percent from last year, according to the Williamson County Association of REALTORS. According to the association’s August report, 1,114 homes were sold in WilCo last month and spent an average of 37 days on the market. “These numbers are no surprise to anyone in the real estate industry,"WCREALTORS President-Elect Shavonne Martin said in a statement. "Inventory and interest rates are still extremely low. … Williamson County is the future of Central Texas. We are seeing unprecedented growth across the county. With areas like Travis County running out of room and becoming less and less affordable, residents are turning to Williamson County.” Median home prices in Williamson County are 7 percent higher than in July 2014, but are still approximately 25 percent less than in Travis County, Martin said.