The 131-seat venue, expected to open in 2011-12, will feature work by emerging artists, with all seats priced at $20. Preservationists argue that a building on the Beaumont’s roof will despoil architect Eero Saarinen’s original design; the new theater’s architect, Hugh Hardy – who worked with Saarinen in designing the Beaumont in the 1960s – says the worries are misplaced.