Conventional construction methods currently contribute up to 30% of global annual carbon emissions. They also produce often highly toxic indoor environments with the release of formaldehyde, benzene, and other chemicals. The push to find healthier, more sustainable alternatives is putting a big spotlight on hemp and its unique properties.
Hemp-based construction projects, both residential and commercial, can already be found around the globe, including in the USA. While hemp-based material costs are relatively high, that’s only because of the limited number of suppliers, which often means shipping what’s essentially simple straw long distances.
Carbon Sequestration
Considered to be the most energy-efficient building material on the market today, hempcrete is also an amazing carbon sequestration tool.
Growing hemp addresses serious issues that have been pointed out by, among others, the UN Intergovernmental Panel on Climate Change, which has recommended that farmers focus on the restoration of over-cultivated and worn-out soil as the easiest way to reduce the global carbon footprint. Soil is a potent, relevant carbon storage medium and contains more carbon than the atmosphere and all living greenery combined. Hemp plants actually increase and redefine the natural ability of the land to absorb “surplus” carbon, the Panel advised.
Related: Hemp-Based Building Materials May Be The Answer To Environmentally-Friendly Construction
Energy Efficiency
Structures built from hempcrete are highly energy efficient due to low thermal conductivity, high thermal capacity and high insulation values. Testing has shown that a hempcrete home is about 80% more energy efficient than a conventional build in temperature control, and delivers an annual CO2 carbon “reduction” of about 8,000 kg. Significantly, hemp-based insulation and finished products stay energy efficient throughout their installed life.
Healthier Living Spaces
Hemp building materials, made from the plant’s stems, are gaining acceptance primarily because they create healthier living spaces. According to the U.S. Green Building Council (USGBC), hemp is a non-toxic feedstock that delivers a number of unique properties for a broad range of building applications.
Related: How Hemp Can Help Fuel A Sustainable Construction Revolution
Hemp stems offer two important byproducts for the construction industry. The plant’s stringy exterior, or bast fibers, provide a cost competitive, sustainable alternative to fiberglass batts as an insulation material. Hemp bast fiber insulation creates an airtight mass with minimal heat loss, and will not mold or mildew. The use of this insulation enables any structure to automatically fulfill LEED design standards for energy efficiency. Hemp bast fiber insulation also has excellent acoustic and high-level fire-resistance capabilities.
The stalk’s thick inner core (hurd, shivs or shives), chopped and mixed with lime and water to create hempcrete, makes for excellent hempcrete walls, and solutions for both load-bearing and non-load-bearing hemp building materials are already on the market.
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