Frank Lloyd Wright designed 1,141 houses, commercial buildings and other works throughout his lifetime, including 532 that were eventually built. As of 2013[update], there were 409 extant structures designed by Wright. Over one-third of the extant structures are on the U.S. National Register of Historic Places, either as part of their own designation or as part of a historic district.[1] UNESCO added eight of Wright's designs to the World Heritage List in July 2019 under the title "The 20th-Century Architecture of Frank Lloyd Wright".[2][3]