First City Tower

1001 Fannin is a skyscraper in downtown Houston, Texas. The building rises 662 feet in height. It contains 49 floors, and was completed in 1981. First City Tower currently stands as the 14th-tallest building in the city. The architectural firm who designed the building was Morris-Aubry, and was built by W. S. Bellows Construction Corporation. The structure is an example of late-modernist architecture. The tower, which formerly housed the headquarters of the now-defunct First City National Bank, now serves as the global headquarters of Waste Management, Inc, and the headquarters of Vinson & Elkins. It also houses the U.S. headquarters of Campus Living Villages.
The building, with Class A office space, has 1,300,000 square feet of office space. The building is noted for its distinctive "staircase cuts" on the north and south facades, and is composed mostly of aluminum and green-tinted glass. These designs were designed to represent the letter "F" for the building's developer and first major tenant, First City Bank, which was itself founded by attorneys of the international law firm Vinson & Elkins. First City Tower was constructed in a diagonal rotation away from Houston's main north-south street grid, which gives the impression that the structure has a larger footprint than it actually does.

Wikipedia