sentences:  Also in 1992, the New York museum building's exhibition and other space was expanded by the addition of an adjoining rectangular tower that stands behind, and taller than, the original spiral, and a renovation of the original building.The new tower was designed by the architectural firm of Gwathmey Siegel & Associates Architects, who analyzed Wright's original sketches when they designed the 10-story limestone tower, which replaced a much smaller structure.It has four additional exhibition galleries with flat walls that are "more appropriate for the display of art".