The Canopy at the Smithsonian Institution's Kogod Courtyard in Washington D.C.

The previously open courtyard of the National Historic Landmark building complex could only be used in spring and autumn for climatic reasons. Now a new Foster + Partners-designed glass roof – comprising three shallow, seamlessly merging cupolas – lies over the open area. A lattice shell from welded steel girders forms the primary structure. A special system com-prising custom-made glass elements with aluminium frames enables this twice-curved structure to be covered with flat, square panes. The article describes in detail the design, production and assembly of this complex piece of architecture.