Seagram Building

From Wikipedia:

This structure, and the International Style in which it was built, had enormous influences on American architecture. One of the style's characteristic traits was to express or articulate the structure of buildings externally.[1] It was a style that argued that the functional utility of the building’s structural elements when made visible, could supplant a formal decorative articulation; and more honestly converse with the public, than any system of applied ornamentation. A building's structural elements should be visible, Mies thought. The Seagram Building, like virtually all large buildings of the time, was built of a steel frame, from which non-structural glass walls were hung. Mies would have preferred the steel frame to be visible to all; however, American building codes required that all structural steel be covered in a fireproof material, usually concrete, because improperly protected steel columns or beams may soften and fail in confined fires.[2] Concrete hid the structure of the building — something Mies wanted to avoid at all costs — so Mies used non-structural bronze-toned I-beams to suggest structure instead. These are visible from the outside of the building, and run vertically, like mullions, surrounding the large glass windows. Now, observers look up and see a "fake and tinted-bronze" structure covering a real steel structure. This method of construction using an interior reinforced concrete shell to support a larger non-structural edifice has since become commonplace. As designed, the building used 1,500 tons of bronze in its construction.


So, in other words, Mies Van Der Rohe was attempting this:




But at a higher cost, he ended up with this:




Now give Philly that Calder out front.