Question: building materials that are eco friendly?
Answer: Recycled Steel. Producing and smelting steel takes a lot of energy. ... , Bamboo. Bamboo is increasing in popularity as a building material. ... , Sheep's Wool. Sheep's wool, of course, can also be regrown quickly. ... , Straw Bales. ... , Precast Concrete. ... , Earth. ... , Plant-Based Polyurethane Rigid Foam.