OTSU, Shiga Pref. -- One of the pavilions at World Expo 2000, slated to run from June to October in Hannover, Germany, is made mostly of bamboo.

While the pavilion, which was constructed using traditional Japanese techniques, received final approval from the German government last week, bamboo buildings are not allowed in Japan.

Gunter Pauli, director of the Swiss-based Zero Emission Research Initiative Foundation, says Japan should approve bamboo as a construction material because it is cheaper, stronger and more environment-friendly than concrete and steel.