Sometimes, the best solutions have existed for years. This is the case with hemp.

Hemp is becoming known as an excellent material to use in construction, bringing wide-reaching benefits not only for the environment, but for our health.

How is hemp being used?

Hemp is a natural, organic crop that can be grown in the UK. Currently, we don’t have many farms growing the crop as the government has underinvested in this area, compared to countries such as France.

Companies including Natural Building Systems are pioneering the use of hemp in construction. One of the most widely-adopted uses is as insulation where it can be used instead of petrochemical products. Other uses include lime hemp concrete and blocks.

TAS is using hemp insulation in a project to renovate the home of a family where health and wellbeing are of paramount concern. We went to Natural Building Systems’ workshop to see a test build, which is pictured in the photos here.

The importance of breathability

One of hemp’s best qualities is its breathability. Often, the problem with new houses is that they are created to be as airtight as possible, which traps moisture inside.

Compared to other insulation materials, hemp is extremely breathable. When used correctly, everything in the building’s envelope is breathing which greatly reduces the risk of damp and mould.

This makes hemp ideal to use in a timber-framed building, where you want to avoid moisture build up as much as possible. We’re often asked whether timber-frame buildings are durable – a well ventilated timber structure can last for centuries, as can hemp.

The health benefits to living in more breathable buildings are becoming widely known. The impact of mould and damp on people’s health has hit headlines in recent years. Any measures to improve air quality are beneficial.

Environmental benefits

According to a report from the European Commission, one hectare of hemp can sequester the same amount of carbon dioxide as a small forest. Even better, it only takes five months to grow.

When in use, the environmental benefits of hemp continue. Concrete made from hemp is a carbon sequester as it stores more carbon than it generates during its construction.

In terms of farming, hemp is an ideal crop as while it doesn’t have to be rotated, it can be. The plant’s dense leaves provide a natural soil cover that reduces water loss and protects against soil erosion. It is also susceptible to fewer pests.

At the moment using hemp insulation is more expensive than man-made alternatives because of availability and the need to import. People aren’t yet familiar with it; hemp is an old technology that has been rediscovered. But as the UK increasingly recognises its benefits, no doubt the price will fall and we’ll see it used across more projects.