Most of us have noticed the recent increase in material costs as global events continue to play out. This has led some contractors to swap plastic pipes and structures that would typically be used on smaller projects with significantly heavier and more burdensome concrete. The change in typical materials is not limited to just piping but also swapping out the standard wood and concrete houses with bamboo, rammed earth, and even Hemp blocks. The more recent advancements in technology allow us to make better use of more carbon-neutral materials.
One of the more interesting materials, Hempcrete, has the potential to replace both concrete & standard insulation for the construction of walls and foundations. One benefit of Hempcrete is that it can be cast in place or constructed of individual lightweight lego blocks. This material also has a much higher R-value than standard concrete, which is similar to foam insulation. It is also fire, rot, and pest resistant, making it suitable in more damp environments. Hempcrete is made using a mixture of Hemp, hydrated lime, and sand.
The main reason this is not more widespread in use has to do with the stigma of cannabis products and the lower compressive strength compared to concrete. While Hemp is legal in the US, there are serious limitations still in place due to the oils it produces, which are similar but not the same as cannabis. Another is the lower compressive strength which may be fine for smaller residential projects but will never fully replace concrete for areas that require much higher compressive strengths.
While not an alternate material, the advent of more readily available 3D printing machines has led to some interesting building methods that even NASA is looking at for potential use in future missions. This is the printing of homes using concrete and other similar on a large scale 3D printer. Currently, these incredible machines are capable of printing out the walls and internal structure of a home in as little as two days during normal 9-5 operations. Who knows, your next home may be constructed with the click of a button in the future.