The benefits of hemp brick are massive, most importantly fireproof and also very good insulation. I am still in the process of making a brick, but quiet bleek as to how it reduces as you process it. I rate ,without experience, 125 plants, processed, is only going to make a couple bricks if we are lucky. That story of 1 Ha of hemp can build you a house is pipe dreams.
Hemp could be the ideal basis for long-term, off-grid sustainable communities, as just one hectare can yield enough hurds for a 135 m2 (1,450 sq ft) house. It can also be grown at or near the construction site to save even more on transportation costs! Source