Hempcrete is even more environmentally friendly than using hemp fibers with polymers.
It is simply the hemp fibers from the stalk, left over after using the leaves and buds for CBD oil / animal fodder / medical marijuana, or whatever the primary use may be, then mixing the chopped fiber with crushed limestone and water, forming it in place, and allowing it to cure.
Hemp fibers, alone among the plant world, when combined with limestone in this way, literally becomes stone. There are bridges and buildings in Europe, built by the Romans, that they have only recently begun realizing were built in this manner, and have lasted for thousands of years and counting.
And, like 3D printing, the costs of building are low, and the expertise and skills needed are also low, allowing for many people to build their own homes with their own labor.
With the US House of Representatives having just passed legislation to legalize cannabis, and expunge the records of those with criminal records of low level possession, this is a gamechanger, and could lead to a huge upswing in real economic recovery.