Skidmore, Owings & Merrill LLP (SOM) is one of the leading architecture, interior design, engineering and urban planning firms in the world. SOM's space on the 10th floor of the Railway Exchange Building has served as the firm’s Chicago office since 1991 and was renovated in 2006. It features models chronicling many of its leading projects, as well as some of the more than 1,700 awards it has received. The American Institute of Architects has recognized SOM twice with its highest honor, the Architecture Firm Award—in 1962 and again in 1996. The firm maintains offices in Chicago, New York, San Francisco, Los Angeles, Washington, D.C., London, Shanghai, Hong Kong, Abu Dhabi and Mumbai.