Nine Spaces Nine Trees was originally commissioned by the City of Seattle in 1983 for their Public Safety Building. When the building was slated for demolition the work became threatened, and a creative solution to preserve the piece was needed. The work was saved through arrangements involving the City of Seattle, the Washington State Arts Commission, and the University of Washington. The work was transferred, redesigned, and reconstructed by Robert Irwin for its new site at the University of Washington.

The work uses simple materials to encourage viewers to focus on their surroundings. The piece creates a maze-like fence structure that is either translucent or opaque depending on your position inside or outside. The nine Winter King Hawthorn trees add a complex layer to the work, dense in the spring and summer and open in the winter, creating both public and private spaces.