Exterior, Metal Siding Material, and Glass Siding Material Stewart explained that the open, curved glass corners is one of the elements that they’re most proud of, as it gives a sense of being more open and light-filled. They went even further by installing low-iron glass in order to create the most crisp, clear views possible.  Photo 7 of 9 in Renzo Piano Building Workshop Brings a New Residential Destination to Soho