Sidley Austin Brown & Wood, among the world's largest law firms, expanded its presence at 1501 K St., traditionally known as the Investment Building. The firm leased 30,800 square feet, adding to its presence on the 6th through 10th floors. 1501 K is a 371,014-square-foot, class-A office building built in 1924 and renovated in 2001. The property features a split atrium, a full-service concierge and a fully equipped on-site fitness facility. Scott Kaufman of JM Zell Partners represented Sidley Austin Brown & Wood. Jackie Connell of The Kaempfer Company represented Kaempfer, the building owners for the Investment Building.