If you’re looking for a strong, green, energy-efficient building material that’s resistant to pretty much everything, hemp might be your best choice. This is the concept being pitched by Greg Flavall and David Madera, owners of a business called Hemp Technologies. They’re some of the first to build with the material in the United States, where industrial hemp hasn’t seen the rise in popularity it enjoys in other countries, thanks to a federal ban on U.S. production.