Hempcrete is the sustainable building material we need in 2024

Jennifer Zamparelli with industrial hemp at HairPeople carbon neutral salon, Dublin
Share now, sow the seeds of love...

Hempoffset will use hempcrete to build sustainable homes

A field of licensed hemp in Ireland.

Hempcrete is a building material made from the woody inner fibres of the hemp plant mixed with a lime-based binder. It is a type of bio-composite material, similar to traditional lime-based concretes, but with the added benefits of being highly sustainable and environmentally friendly.

One of the main advantages of hempcrete is its carbon sequestration properties. The hemp plant is a highly efficient carbon sink, absorbing CO2 from the atmosphere as it grows. When the plant is used to make hempcrete, the carbon stored in the fibres is locked away in the building material, effectively removing it from the atmosphere. This makes hempcrete a valuable tool in the fight against climate change.

Our vision is to plant hemp at scale, to stop climate change, and to build sustainable, hempcrete homes for everyone who wants or needs one.

Our audacious goal is to grow one billion hectares of hemp every year. This will produce up to 23 billion metric tonnes of carbon fibre. Which is a lot. And we need to sequester (lock away) as much of the carbon in the hemp fibre as possible. We believe that the most effective way to use all the fibre is in the production of hempcrete, which we will use to 3D-print houses, and use in modular blocks for commercial buildings such as data centres and food storage facilities.

The question of land may seem like an obstacle but, in reality, hemp is a very effective and efficient crop to grow, with high-value outputs. Our ambition is to have hemp growing on one billion hectares, with each ha removing up to 23 mt/CO2 annually (photosynthesis removes more CO2 from the air than can be measured by crop weight), double, or even triple that in hot countries. This will require just 10% of the world’s arable land, with hemp also thriving in marginal land. Currently, 40% of the world’s arable land is used for dairy and livestock production, which is both a poor use of land for nutritional output, and also contributes significantly to GHG emissions.

The last global survey by the United Nations, in 2005, found that an estimated 100 million people were homeless worldwide. As many as 1.6 billion people lack adequate housing. We will fix this.

What is hempcrete’s chemistry?

We will use the harvested hemp fibre to make hempcrete (four parts hemp, one part each of lime and water) and 3D-print sustainable houses. 100% of the captured CO2 can be considered durably sequestered as it will be bound up in hempcrete. Hemp absorbs Carbon as CO2 from the atmosphere, releases the O2 and chelates the Carbon into stable molecules which constitute the plants’ biomass. We are sequestering Carbon from atmospheric CO2, combining it with silicates and other elements to form the molecules which comprise the plants’ biomass. This biomass is dried and mixed with hydraulic lime and water to form hempcrete, an enduring, inert (chemically inactive), stable, fire-resistant bio-composite construction material with great insulation and anti-mould properties. Hempcrete buildings from the 8th Century AD still stand in Europe, so there is no issue with durability.

Felix and Gary from Hempoffset with a hempcrete block at Ireland’s Hemp Coop conference 2022

By using hemp fibre to make hempcrete, we can build houses for everyone in the world that needs a home. We expect our houses to stand for hundreds of years, which means that the CO2 is safely locked away. Hempcrete has the extra benefit of continuing to absorb CO2 from the air over those hundreds of years, through carbonation. So a further 25% of the weight of the hempcrete is absorbed in CO2 every 100 years!

Wikipedia: Hempcrete is easier to work with than traditional lime mixes and acts as an insulator and moisture regulator. It lacks the brittleness of concrete and consequently does not need expansion joints. The result is a lightweight insulating material ideal for most climates as it combines insulation and thermal mass.

Hempcrete is as durable as concrete but 6-8 times lighter. Concrete production contributes 8% of GHG emissions, so we plan to work with concrete producers to leverage their existing infrastructure to bring hempcrete to market quickly and economically. Hempcrete does not have the compressive strength of concrete, so it will require structural supports.

Hempcrete carbonation

Carbonation refers to the process in which the lime in the hempcrete reacts with carbon dioxide in the air, causing it to harden and become more durable over time. Carbonation is a natural process that occurs over time, making the hempcrete stronger and more resistant to moisture. The carbonation process also has the added benefit of sequestering carbon, which can help to offset the carbon footprint of the other building materials used.

Hemp blocks in Ireland

There are suppliers of hemp blocks in Ireland, typically imported from other EU countries. Hempoffset.com aims to be the exchange platform for hemp blocks in Ireland and globally. Contact us to register your interest in supplying or sourcing hemp blocks.

Industrial hemp’s main power source is sunshine. There is some diesel used in crop harvesting, processing and transportation. The 3D printing system for hempcrete houses will be powered by electricity from a diesel generator and mixing is done by diesel-powered machines. Our next stage vision includes powering machinery with hemp biodiesel from our crops, a sustainable, carbon-neutral energy source.

We use conservative figures for hemp here, btw!

Hemp has multiple additional benefits

Because hemp does such an amazingly efficient job of converting CO2 to carbon compounds, the crop’s applications are almost limitless. To end fossil fuels, hemp is the only solution that allows us to carry on with everything we’re used to. 

We’re working with makers all over the world, to offer products in housing, including hempcrete homes, modular hemp blocks, and hemp fibre insulation. These products will be of better quality than existing products, the only carbon positive construction materials in their markets.

Tangible and measurable environmental co-benefits of hempcrete include:

  • Carbon storage – One hectare of hemp sequesters 7 to 15 tonnes of CO2, similar to the amount sequestered by a young forest, but it only takes five months to grow.
  • Breaking the cycle of diseases – Hemp helps to break the cycle of diseases when used in crop rotation.
  • Soil erosion prevention – Dense leaves of hemp become a natural soil cover, reducing water loss and protecting against soil erosion. Hemp covers the ground just three weeks after germination.
  • Biodiversity – Flowering cycle usually occurs between July and September, coinciding with a lack of pollen production from other crops. Hemp produces large amounts of pollen, just when they need it most.
  • Low or no use of pesticides – Hemp is tough, so the use of insecticides, herbicides, and fungicides can be avoided in most cases. This also benefits bees.

To learn more about how we can help your business go carbon neutral, quickly and effectively, get in touch!

Learn more

All about hemp

Hemp resource guide

Hemp Manifesto

Hemp Carbon Credits

Humans and hemp

UN hemp report

Read our report on the Irish hemp coop conference 2022, including hempcrete blocks

Hempcrete on Wikipedia: https://en.wikipedia.org/wiki/Hempcrete

BRE: https://projects.bre.co.uk/hemphomes/

More, useful hempcrete links







Latest posts

 | Website

Founder and CEO at Hempoffset.com and TaoClimate.com.

Hempoffset works with hemp growers and makers worldwide, to capture and sequester CO2 at scale, while building a sustainable world.

Tao Climate works with companies and individuals that want to measure, minimise and manage their carbon footprints. Tao Climate is the way to carbon neutral.

We are proud members of the Google Startups for Sustainable Development program.

Share now, sow the seeds of love...

By Gary Byrnes

Founder and CEO at Hempoffset.com and TaoClimate.com. Hempoffset works with hemp growers and makers worldwide, to capture and sequester CO2 at scale, while building a sustainable world. Tao Climate works with companies and individuals that want to measure, minimise and manage their carbon footprints. Tao Climate is the way to carbon neutral. We are proud members of the Google Startups for Sustainable Development program.

Now, what's your opinion?

This site uses Akismet to reduce spam. Learn how your comment data is processed.

Skip to content