The Hemp Block Company is helping change the construction industry with their environmentally friendly hempcrete blocks. FRANK talks to cofounder Neil Stephen about what makes them the building blocks of the future.

Hi Neil. What is your background and why did you start the Hemp Block company?

Neil Stephen: My background is in sales. I used to be a sales director for a small property developer in Hertfordshire, so I have been in the property industry for a long time.

I co-founded The Hemp Block Company with my good friend, William Stanwix, who has been working with hempcrete for 15 years. Our main aims are to help lower carbon emissions from the construction industry, while also creating healthier living environments, by making hempcrete more accessible.

Can you tell us what exactly is hempcrete and what is a Hemp Block?

Neil Stephen: Our blocks are simply a dried form of hempcrete, which is a mix of hemp shiv (the stem of the hemp plant), lime and water. Hemp shiv is the chopped up woody stalk of the industrial hemp plant and is the waste from the hemp fibre industry. It is packed full of the carbon that the plant has taken out of the atmosphere during its growth.

What makes our blocks unique is that we use hydrated lime as the binder along with a probiotic, which makes them more environmentally friendly and stable throughout the whole block.

How can you use them?

Neil Stephen: The blocks are non-structural so need to be used in conjunction with either a timber or steel frame. Our blocks are the insulation envelope, in fact, one of the main benefits of the blocks is their insulative properties. They also have what is known as thermal mass. They help control humidity within the home and are a great acoustic insulator too.


In terms of the impact on the environment, how does a Hemp Block compare to a regular concrete or sand brick?

Neil Stephen: There is no comparison really. Our blocks are carbon negative compared to concrete blocks which are high in embodied carbon.

You don’t need cement if you use Hemp Blocks. You simply use a traditional lime or insulating mortar, which again is better for the planet. Cement is one of the planet’s biggest polluters, responsible for around 8% of global emissions.

The blocks are Carbon Negative – can you explain what that means?

Neil Stephen: Carbon negative basically means the hemp has sequestered more carbon from the atmosphere as it grows, than the amount of carbon that is used to make the blocks. A study from the University of Milan has confirmed the blocks have sequestered 11kg of carbon per cubic metre.


Are Hemp Blocks a lot more expensive than regular bricks?

Neil Stephen: You can’t really do a direct comparison as they are not building blocks. However, as a direct comparison wall type to wall type, they are around 5% more expensive. In the long term, you would save money, though. Because they have thermal mass as well as insulating, they make for a more even ambient temperature, which helps lower your bills long term.

Are you seeing an increase in demand for Hemp Blocks?

Neil Stephen: We have seen a huge increase in demand. People are becoming more aware, not only of the benefits to the planet and running costs but more importantly to the quality of the air we breathe within our homes.

I think when you weigh up all the benefits of using Hemp Blocks over current build methods, like cavity walls, the decision is fairly obvious. They are a type of natural insulation that doesn’t cost the Earth.

What is the most exciting or interesting building project you’ve provided Hemp Blocks for?

Neil Stephen: Every project is exciting, knowing how much good we are doing for the planet. However, for me, I think it must be a children’s nursery in Buckinghamshire, where it provides a warm, calming atmosphere for the children to learn and play in.

What is the future for hempcrete? Could it one day replace concrete bricks altogether?

Neil Stephen: I wouldn’t be that bold, but I believe it will certainly become more mainstream as people look for healthier construction methods and discover hempcrete offers a cost-effective healthier alternative. I believe the future is very bright for hempcrete in all its forms, as people become more aware of the cost to our health and to the environment of current build methods. The future is bright, the future is hemp!




For more information about The Hemp Block Company, have a look at their website here.

Image: Neil Stephen, right, with co-founder Will Stanwix.

Other image credits: Andy Harris


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