Major green features are the fast-growing raw material that grows in only 5 years. Actually a bamboo grows from sprout in just 2 years to full size. Then it takes 3 years, until the wood has hardened. Thus, the bamboo plant is ripe for the harvesting or it will be broken in the next few years in a natural way by storm. Within 5 years enough sprouts have grown to replace, it is a natural selection. In fact, 25% of a bamboo forest can be harvested every year without compromising the nature in any way.