Chicago's Fox 32 reports that the production will shift from Detroit to downtown Chicago in early November, with a shoot lasting four or five days, where both Ben Affleck's Batman and Henry Cavill's Superman are said to be "duking it out." The city will be doubling for Metropolis in these scenes, although it isn't known yet if they plan on shooting any Gotham sequences while they're in town as well. The shooting will then shift to surrounding areas of the Windy City for a week and a half.
It isn't known yet which "surrounding areas" of Chicago will be used in Batman v Superman: Dawn of Justice. It's worth noting that when we visited the Man of Steel set back in 2011, the town of Plano, Illinois, which is located outside of Chicago, was used for Clark Kent's hometown of Smallville, so it's possible they may return to that location for Batman v Superman: Dawn of Justice.
Take a look at the Fox 32 video report below, and stay tuned for more details as production continues on Batman v Superman: Dawn of Justice.
Batman v Superman: Dawn of Justice comes to theaters March 25th, 2016 and stars Henry Cavill, Ben Affleck, Amy Adams, Diane Lane, Laurence Fishburne, Gal Gadot, Jesse Eisenberg, Jeremy Irons. The film is directed by Zack Snyder.