Todd and Billie to Get Arty for the Big Green.  Expect to be hear a lot about Todd Williams and Billie Tsien in the weeks and months to come. First up, their much anticipated (and highly controversial) new building for the Barnes Foundation in Philadelphia, which opens imminently. Second, the fate of their building for the American Folk Art Museum (now owned by MoMA) hangs in the balance, with Jean Nouvel’s tower looming on the horizon. Third comes the announcement that the pair will renovate and expand the Hood Art Museum at Dartmouth College in Hanover, New Hampshire. The project will include new and renovated galleries for Darmouth’s art collection, which dates to 1772.