Since construction is all about building something new, we sometimes forget about the flip side of the coin: tearing something down and disposing of building materials. Biodegradable materials can change that disposal process into something more eco-friendly: Instead of a giant scrap heap of waste products and chemicals, they result in products that degrade naturally without contaminating the soil. An excellent example is biodegradable paint, which mimics the old practice of creating paint from a milk-based recipe. The Old Fashioned Milk Paint Co. uses milk protein, lime and mineral pigments to create an organic paint mixture [source: MilkPaint].
Using recycled products -- like recycled fiberglass insulation, for example -- is a good start toward being eco-friendly, but products that naturally break down without releasing toxins into the Earth are even better. Outside of the United States, hemp is used in construction for everything from building foundations to insulation [source: Hemphasis]. United States laws forbid the growth of industrial hemp -- a low-THC cousin of marijuana -- but at least one company is importing the hemp to create Hemcrete, a hemp and lime mixture similar to concrete [source: BuildingGreen].
Hemp isn't the only biodegradable structural material on the block -- in fact, our next green building technology has been in use for thousands of years.