Plans to expand the museum, which existed in the 1995 Forest Park Master Plan and the museum's 2000 Strategic Plan, began in earnest in 2005, when the museum board selected the British architect Sir David Chipperfield to design the expansion; Michel Desvigne was selected as landscape architect. The St. Louis-based firm, Hellmuth, Obata, and Kassabaum (HOK) was the architect of record to work with the construction team.