One of the most promising natural building technologies — “natural” meaning minimally processed, low energy intensive materials — is hemcrete, a mixture of chopped hemp hurds and lime plaster. It can be pressed into blocks, or stuffed or sprayed into wall cavities, and provides excellent thermal insulation, thermal mass, and moisture durability.
Check out this project in North Carolina. It is the first hemcrete structure in North America, but there are many in the UK and Europe, and they are meeting or exceeding performance expectations. Hemp is one of the most common and utilitarian plants anywhere, growing easily in all sorts of conditions and providing edible oils, proteins, fibers and more. Once everybody gets past the initial “Don’t smoke it!” jokes, hemp will surely emerge as a mainstay of a more sustainable, low-carbon economy.