Is hemp insulation an environmentally friendly construction choice worth considering for your project?
In the ongoing quest for sustainable building materials, hemp insulation stands out as a promising contender. This versatile plant, with a history dating back around 50,000 years, is increasingly being recognised for its numerous benefits.
Mark Lynn, the managing director of sustainable insulation firm Eden Renewable Innovations Ltd and Chair of the Alliance for Sustainable Building Products, is an expert in building insulation and an advocate for healthy, sustainable buildings. He emphasises the potential of hemp insulation, stating that while it may be slightly more expensive than mineral wool, it is cheaper than sheep's wool.
One of the key advantages of hemp insulation is its versatility across a range of uses, especially in the building industry. It can be used in various locations within the wall fabric of a building, preventing the buildup of moisture which can encourage mould and rot. Hemp insulation is also vapour permeable, allowing moisture to pass through it, and is resistant to insects, bacteria, mould, and fungi, making it an ideal choice for eco-friendly homes.
Hemp's sound deadening properties make it great for soundproofing, a feature that is increasingly important in modern homes. Moreover, hemp is lightweight, breathable, and mould resistant, ensuring comfort and health for occupants.
The innermost fibres of the hemp plant are used to create natural insulation materials. These fibres are processed into a variety of products, including hemp insulation boards, which have an average cost of £15-£20 per square metre. For those seeking a more cost-effective option, Hemspan's BIOHAUS composite hemp panels range from £7.50 to £28 per square metre, depending on thickness and rigidity of the materials.
Hemp's sustainability credentials are impressive. It is less resource-intensive to cultivate compared to crops like cotton, according to Mark Lynn of Eden Renewables. Hemp plants require little water or pesticides and insecticides, making them a more environmentally friendly choice.
But perhaps the most compelling reason to consider hemp insulation is its carbon sequestration capabilities. Hemp plants capture and store carbon from the atmosphere as they grow, acting as a carbon sink while saving energy. Regeneratively farmed industrial hemp can sequester up to 11 tonnes of CO2 annually through its stem and an additional six tonnes of CO2 per hectare into the soil each year. This makes hemp a valuable tool for boosting a home's embodied carbon credentials.
In Germany, the Schönthaler Bausteinwerk is a pioneering company that produces and distributes hemp-based insulating materials, specifically hemp-lime (also called Hempcrete) products such as hemp blocks for walls and interior insulation, with official German certification for these products. The UK also has several suppliers providing hemp insulation, including Margent Farm, Ecomerchant, Natural Insulations, Celtic Sustainables, Hemspan, and IndiNature.
In conclusion, hemp insulation offers a sustainable, cost-effective, and eco-friendly solution for modern homes. Its versatility, durability, and carbon sequestration capabilities make it a compelling choice for those looking to reduce their carbon footprint and create healthier, more sustainable living spaces.
