Buro Happold has also completed the designs of a number of cardboard structures, notably the Japan Pavilion for Expo 2000 in Hanover with Shigeru Ban and Frei Otto, consisting of a gridshell of paper tubes (the structure was reinforced with steel in order to comply with fire regulations, though the tubular structure was itself structurally sufficient). The firm has worked with Shigeru Ban on a number of other projects. Another design in cardboard was the Westborough School cardboard classroom in Westcliff.