This stair represents a revival of what the English call a “cantilever stair”. An early example of the cantilever stair is Palladio’s stairs at the Accademia in Venice. The original principle is simple: each stone tread is built into the wall and overlaps the treads above and below. That way each tread is supported from below and reacts to the tread above with the resulting torque carried by the wall. The treads do not actually bend as cantilever off the wall. In this instance, the concept uses a glass plane made of 2 planes of 3/8in glass laminated around a 7/8in plate, all tempered to resist the torque, and steel 64in by 6in tubes and aluminum plates to make up the risers and treads.