Yes, the Braves considered putting a retractable roof on their new stadium. “I think it was a relatively brief conversation,” Derek Schiller, the team’s president of business, recalled. After rejecting a roof for reasons of cost and baseball tradition, the Braves asked the architects of SunTrust Park for a design that “would have as many of our seats covered as possible, outside of having a roof,” Schiller said. One result of that directive is easily noticed at the stadium construction site in Cobb County these days: The steel framework for a wide canopy hangs above the upper deck, protruding as much as 60 feet over what eventually will be rows of seats. Whether protection from sun and rain will make many fans want to sit near the top of the ballpark remains to be seen. But the 108,000-square-foot canopy will provide the option, as well as an architectural element.