The house includes 7,000 square feet of substructure that sits on the underside of the hill from one side, and is open to the sky on the other. The glass plates seen at the forefront of this image serve as skylights to the substructure, which includes an indoor pool, mudroom, library, kitchen, gym, media room, and a walk-in cheese locker and wine room.  Photo 4 of 15 in A Thomas Phifer-Designed Glass-and-Steel Masterpiece For Sale