Hemp: Sustainable Green Building Solutions

New “green” construction solutions have the potential to revolutionise the way New Zealand builds, and could help boost the economy by billions, a business innovation expert says. The construction and building sector accounts for 39% of carbon dioxide emissions globally, and in New Zealand the built environment is responsible for 20% of emissions. At the same time, global construction waste is set to double to 2.2 billion tonnes by 2025.

How Can Hemp Help?

Did you know that Industrial hemp provides one of the world’s most versatile and sustainable building materials? Hemp hurd, which is the woody core from the centre of the stalk of the plant is a modern solution to other toxic materials that are used in the building world today. This woody core is chipped and mixed with water, lime and a binder to create a high performing alternative to concrete, also known as hempcrete.  The hemp core has a high silica content which allows it to bind well with lime. Hempcrete creates beautiful, stone like walls that are warm, modern, affordable and stylish.

Hempcrete can be poured manually around a timber framework providing insulation and heat storage qualities to the resulting living space. It can also be sprayed to help reduce installation times and lower water usage, making it more acceptable to the modern construction industry. It can even be manufactured in to blocks, which can be laid in the same manner as masonry blocks or bricks, which will provide insulation and moisture management to the structure. Another way is to make prefabricated panels, combining Hempcrete and Hemp fibre, a quick system fabricated off site which provides a fast system of creating a building envelope to the domestic and industrial sectors.

History of Hempcrete

Hempcrete has been used in house building for hundreds of years. It was first discovered in France as far back as the 6th century.

Benefits of building with Hempcrete

Insulation: Hempcrete provides excellent thermal properties, when compared to other types of building materials.
Constant temperature: Whether you live in cool or warm climates, hempcrete maintains a constant temperature, due to the insulating properties as well as thermal mass, which is excellent for all climates, especially in very hot and cold areas.
No dampness in walls: Since hempcrete is breathable, you don’t have to worry about damp. Both the hempcrete and the lime plaster work to absorb moisture in the air especially during high humidity, as moisture is released back into the air when humidity levels drop. As a result, mold growth is a thing of the past because hempcrete keeps humidity at levels that prevent bacterial growth.
Non-toxic: There is no need for fungicides or pesticides to grow hemp, compared with the production of conventional construction materials, which involve toxic and synthetic chemicals.
Fire retardant: Houses built with hempcrete char a little when they’re burnt, but they’re known to be more fire resistant.

As we are becoming a more and more environmentally conscious society, it is important to consider the materials that we are building our homes, schools, and buildings from. It is no longer just about the food we eat and the packaging that it is wrapped in, it is so much more than that.

Luckily, there are companies starting to make the move to more environmentally sustainable materials, such as erkhartconstruction.co.nz who are using hempcrete in their new builds with great success. Hemp Farm NZ Ltd will be producing hemp hurd and fibre from their new fibre processing line, which has been installed at their Partners facility, NZNF (New Zealand natural Fibres) facility early 2021.

Using hemp in the daily diet and in our homes can make a significant impact on our health and the health of our environment.