The Rookery Building is a historic office building in downtown Chicago’s financial district. It was completed in 1888 by Daniel Burnham and John Wellborn Root, is considered one of their masterpiece buildings, and was the location of their offices at one point. While the building is only 12 stories, 181 feet, it is the oldest standing high-rise in Chicago. The building blending accepted and new building techniques, by using load-bearing exterior walls, and steel frame interior. The building underwent 3 major renovations in the 20th century, beginning with the renovation of the lobby by Frank Lloyd Wright from 1905-1907, adding carved white marble, simplified iron work, and his trademark planters and lighting. The second major renovation was done by Wright’s former assistant William Drummond in 1931, where he modernized interior elements and replaced the elevators, as well as added art deco detailing. Finally in 1992, Daprato Rigali Studios returned the building to Wright’s design and reopened the light court after it had been covered to protect against leaks. The Rookery Building was added to the National Register of Historic Places in 1970, designated as a Chicago Landmark in 1972, and a National Historic Landmark in 1975.