Is hemp the building material of the future? Perhaps. Houses built with hemp use less energy, create less waste, and cost less money to heat or cool. Hemp can be fashioned into fiberboard, lightweight cement roofing tiles, wallboard and other wood-like materials [source: Priesnitz].
But hemp as insulation is one of the most popular ways to use the plant. Hemp insulates better than many other materials, such as cotton or wool. Hemp insulation is a composite material, in which the plant's fibers are bound with another substance. It has a low U-value, a measurement which gauges how much heat passes through a particular material. The lower the U-value, the better the material insulates. In fact, Hemp insulation has a U-value of .040, which is comparable to the U-value rate of 8-inches of fiberglass insulation [source: The Hemp Company and Combustion Research].
Hemp's R-value, which measures a material's resistance to heat flow, is also good and similar to other fibrous insulation products -- about R-3.5 per inch of thickness [source: U.S. Department of Energy]. The more the material restricts the flow of heat, the higher its R-value.
Hemp also absorbs moisture, which reduces humidity and condensation of the surrounding air, and inhibits the growth of mold [source: The Hemp Company]. While hemp insulation can help a homeowner save money on energy, its real advantage is that the plant is environmentally friendly. It takes very little energy to grow and process hemp into insulation. In addition, hemp scrubs the atmosphere of greenhouse gases [source: The Hemp Company].
So if hemp can be used as a building material and is great insulator -- plus it's environmentally friendly to boot, why aren't more builders in the United States using it? Read on to find out.