It could be argued that most building materials are recycled: wood, brick, and stone, after all, are just reuses of other materials. But today, driven by economic and environmental forces as well as aesthetic considerations, builders are experimenting with a wide variety of recycled and reclaimed materials – wood used in previous buildings, discarded shipping containers, cans, bottles, tires, and phone books. Many modern buildings make use of just about anything that might provide shelter, insulation, or decoration.