Making concrete releases a lot of CO2, yet it is one of the most used construction materials. An alternative to this material is hempcrete, a concrete-like material made with, as the name implies, hemp. Tav Group is a Tel Aviv based architecture firm that has used hempcrete to build a house in the northern Israeli city of Ein Hod.
Hempcrete is a biocomposite material that is made from hemp mixed with lime and water. Hemp is a variety of the cannabis plant, but has barely or no psychoactive effects. It is one of the fastest growing plants in the world and can be used to make products such as paper, textiles, biodegradable plastics, paint, insulation, and much more.
Ein Hod has a climate that often hits 30 degrees Celsius (90 degrees Fahrenheit) during the summer. Not only does hempcrete eliminate the toxic manufacturing process of making concrete, but it also offers high insulation values, which makes the house comfortable even in a hot Mediterranean climate. Thus, the inhabitants do not need to use air conditioning. Hempcrete is more porous than traditional concrete, allowing for better humidity control. In addition, hemp absorbs carbon emissions.
The project is a study in architectural possibilities of organic building materials. For the lower floors of the house, the firm used local stone, solely collected from the site’s excavation material. For the upper floors, they used hempcrete. Lime plaster is applied externally.
On the inside, partitioning is made of rammed earth and the interior plaster is earth based. The ceilings are supported by wooden beams. No cement was used, except for the mandatory safety room and foundations.
For another project with hempcrete, click here.
Photos: Yaeli Gavrieli / Yoav Etiel