Timber, one of the oldest materials used in building construction has now generated the biggest new idea in sustainable building: Mass Timber. But Mass Timber isn’t just ordinary wood. These products (also recognized as cross-laminated timber) are thick, compressed layers of wood, creating strong, structural load-bearing elements that can be constructed into panelized components. They are typically formed through lamination, fasteners, or adhesives and are often manufactured off-site for load-bearing wall, floor, and roof construction which means faster construction time and smaller teams.
Cross-laminated timber itself has been in use for decades, particularly in Austria and Germany, and is arguably the first major structural innovation since the invention of reinforced concrete more than 150 years ago. Interest in the material is surging along with concern about the greenhouse-gas emissions associated with concrete and steel. The production of construction materials such as steel, cement, and glass accounts for 10% of global energy-related CO2 emissions, according to a United Nations report.
Hemp, like timber, is a plant-based material that can be used in construction to achieve sustainable and environmental goals in the building. This material is used most notably in Hempcrete buildings and HempWool insulation. It's been used in Europe for far longer than in North America but is quickly becoming a more accessible and mainstream building material here in the U.S.
To understand the significant environmental benefits of hemp-based products, it’s best, to begin with, hemp’s unique growth period. Hemp can go from seed to a ready-to-harvest material in as little as 120 days, making it one of the most rapidly-renewable materials in the world. During its growth cycle, Industrial Hemp can sequester 9.8 tons of CO2 per acre. In comparison, some softwoods can take up to 120 years to create the same amount of usable biomass that a few acres of hemp can produce in 3 months. It is a key highlight however that both Timber and Hemp are then able to store carbon for their entire lifecycle, even during their use as building materials.
The carbon impact of building materials is significant. Concrete, for instance, has a colossal carbon footprint — at least 8% of global emissions caused by humans come from the cement industry alone and Mass Timber is an alternative to its production. Polyurethane (Spray Foam insulation) requires an input of 14 times more energy to achieve the same thermal performance as HempWool insulation, whereas HempWool acts as a 1:1 replacement for conventional insulations. For those wishing to reduce their impact during construction and renovations, it’s worthwhile to consider the embodied energy of products as well as the lifecycle of these materials after use. HempWool insulation, made up of 90% hemp fibers can biodegrade or can be reused or recycled at the end of its life when compared to other insulation materials which cannot.
Hemp, cross-laminated timber, and other engineered plant-based building products can benefit the climate in three ways: plants capture and store carbon as they grow; long-lived wood products lock in carbon and hemp is a rapidly renewable carbon-storing material, and these products can be used instead of high-impact materials like concrete or polyurethane.
Both Mass Timber and Hemp in construction have a similar hurdle in changing the social perceptions of these materials. It takes political will and investment to move away from the destructive ‘business as usual' approach to building and move towards a future that is more sustainable and healthy for all. Hempitecture is currently developing a US-based manufacturing facility that will utilize more than 75% of renewable energy for production and facility use. That, alongside emerging US agriculture partnerships, Hempitecture will soon offer products that are both USA-made and grown materials that will cut the emission cost as these regenerative and healthy materials will not be imported internationally. In conjunction with cross-laminated timber and other sustainable materials available for construction, we are excited to be a part of an industry that is making strides towards healthier products and building for both the people and the planet.
Catch Hempitecture at Booth #1224 as an exhibitor at the upcoming Mass Timber Conference, April 12-14th in Portland, Oregon.