The evolution of the exterior skin in office/institutional buildings has certainly changed throughout the years and you can clearly see that when you look at the Lever House, Seagram Building, Citicorp and Lipstick buildings. When you look at those buildings you can clearly compare their massing strategies as well as their exterior skin and you can see how they differ from each other as well as how they learned from one another. One good example of this is when you look at and compare the Lever House and the Seagram Building to each other you can clearly spot the differences and the similarities they share.

The Lever House was built in 1951 and you can see by just looking at the building you can see right away it has two different types of glass being used a transparent glass where you can see into the offices and a greenish window that is most likely covering mechanical equipment and drop ceilings. You can also see that the Lever House has an offset as well as a relief on the ground floor and in the top part of the building. When you walk across and look at the Seagram Building which was built in 1958 you can see some similar qualities in the exterior façade that it mimics from the Lever House. You see the windows in the Seagram building are transparent with a yellowish color to it and this building has only one relief and it can be seen on the ground floor you can see and one major difference between the Lever House and the Seagram Building in the way the building is laid out you can clearly see that the everything inside the Seagram building is aligned and center as well as the façade has spandrel just like the Lever House just that these spandrels are colored black. Both the Lever House and the Seagram where built in the same century just a couple of years apart from each other and you can clearly see what the architect (Mies van der Rohe) of the Seagram Building learned from the Lever House and took into consideration when he was designing the Seagram Building.