Engineers have been dreaming about putting up a mile high building--the ultimate skyscraper--ever since Frank Lloyd Wright proposed one for Chicago in the 1950s. Recently, a group of experts studied the implications of such a structure for a presentation at the 1986 Tall Buildings Conference. The building is concrete, 500 feet square at the base in order to obtain a good aspect (height/width) ratio, arranged in modules 100 feet square. Diamond shaped windows are the result of designing a trussed megatube, an extremely rigid exterior that resists wind loads and other forces.
There are several reasons why concrete was chosen for this mile-high structure: combining architecture and structure saves a great deal of cost in the building skin. Concrete is a naturally fireproof material that does not, in general, require additional fireproofing. Monolithic concrete is able to absorb thermal movements, shrinkage and creep, and foundation movements. Because of the continuity of concrete members, deflections are low and the structure is inherently stiffer than any other kind of construction.