The design of CCTV headquarters defies the popular conception of a skyscraper and broke Beijing's building codes so it required approval of a special review panel. The standard systems for engineering gravity and lateral loads in buildings didn't apply to the CCTV building that is formed by two leaning towers, each bent 90 degrees at the top and bottom to form a continuous loop.
The engineer's solution was to create a structural "tube" of diagonal supports. The irregular pattern of thie "diagrid" system reflects the distribution of forces across the tube's surface. Designed by Rem Koolhaas and Ole Scheeren and engineered by Ove Arup, the new CCTV tower rethinks what a skyscraper can be. It's scheduled for completion in 2008.