“”We used robust materials that have a kind of integrity to them,” Anderson says.  The freestanding dining hall - Anderson calls it “a big, rusty barn” - is clad in that most exquisite of urbane-country-casual building materials: corrugated Cor-Ten steel.  As it ages, Cor-Ten forms a protective coat of rich red rust.  (The contractor, missing the point, at first balked about installing it.)  Inside the cafeteria, rural forms take over: a food service station is modeled after a grain hopper; ducts arch overhead like the fingers of a crazed rake.  The employees’ health club is on the lower level.  “It’s clearly not a nine-to-five gig.” Anderson says.”