. Ban is attracted to using paper because it is low cost, recyclable, low-tech and replaceable. The last aspect of Ban’s influences is his humanitarianism and his attraction to ecological architecture. Ban's work with paper and other materials is heavily based on its sustainability and because it produces very little waste. As a result of this, Ban's DIY refugee shelters (used in Japan after the Kobe earthquake, in Turkey, Rwanda and around the world) are very popular and effective for low-cost disaster relief-housing.