The Council on Tall Buildings and Urban Habitat (CTBUH) is an international body in the field of tall buildings and sustainable urban design. A not-for-profit organization based at the Illinois Institute of Technology in the city of Chicago, Illinois, the CTBUH announces the title of The World s Tallest Building and is an authority on the official height of tall buildings. Its stated mission is to study and report "on all aspects of the planning, design, and construction of tall buildings." The Council was founded at Lehigh University in 1969, where its office remained until October 2003, when it moved to the Illinois Institute of Technology in Chicago.