Wednesday, February 27, 2013

Growing Buildings


We often tend to focus on commercial projects when discussing what steps can be taken to construct green buildings.  However, green construction has also taken off in the residential market and there are a variety of different building products and techniques available.

One of the more interesting products I have come across lately (LINK) is called Hencrete.  Hemcrete is composed of hemp, lime, and water, and is being used to construct sustainable carbon negative building components.  The final product is a durable material that provides an airtight seal and can be used in many areas where traditionally framed walls would be used.  One advantage of Hemcrete is that it is very adaptive to changes in humidity and will not rot like a traditional wall if water is allowed to infiltrate the wall.  The biggest breakthrough with this new product is that it is carbon negative.  This means that there is more CO2 locked up throughout the growing and harvesting process of the hemp than the amount of carbon that is released during the production of the lime, which is used as the binder.  This is a very difficult accomplishment to achieve and could make Hemcrete a very popular product for using in future sustainable structures. 

Hemcrete can also be used for other building elements such as roof insulation and flooring.  Unlike traditional building materials, 100% of the product can be recycled when the structure is deconstructed.  Although a wall made out of plants may seem like a fire hazard, Hemcrete is actually fireproof due to the lime binder coating the plant material.

One issue with using Hemcrete is that it is currently priced much higher than traditional wall materials.  However, as the popularity of this product begins to grow and production costs decrease, Hemcrete could become a very common building product.  Unfortunately, the species of hemp required to make Hemcrete is illegal to grow in the United States, but the product has become extremely popular in Europe and other countries.  Advocates of sustainable construction are working to change laws to allow Hemcrete to be grown in the US, instead of having to import the product at high costs.

Below is a video demonstrating the production and application processes of Hemcrete:


2 comments:

  1. Wow, there are so many things to comment about here. Of course the biggest elephant in the room is the controversial nature of the building material itself. This seems to me one more argument supporting the idea that the end of cannabis prohibition in America is long overdue. Time and time again I have heard of environmentally beneficial products made from hemp that are not being fully exploited in America. Furthermore, other countries that do recognize the potential of hemp are leading the race in infrastructure, innovation, and are breaking ground in new markets while America does nothing. On the other hand, I did observe that the application of the material is similar to that of shotcrete, a type of cement that is used in America. That means that should this material become more available, it would be possible for American workers to pick it up with ease and incorporate it into existing practices. Surely a negative carbon footprint should be an incentive to do so.

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  2. Hemcrete definitely promises a brighter future in sustainable concreting. It can certainly change the way we build due the versatility in the applications of hempcrete. It’s amazing how they are incorporating natural materials such as hemp into making a construction material so rigid that it could definitely compete with conventional concrete in terms of strength and durability. Hemp is legal in the US. The way the law is written, and it was further clarified, as long as the THC containing substance does not allow for ingestion, absorption or inhalation into the body it is not regulated by the DEA. The real reason is likely that it’s not economical at the moment.

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