Carbon-Positive Materials: No Longer Far-Fetched, Increasingly Available
By Abigail Knopps and Diksha Jain
What is happening now?
According to a 2018 report from the World Green Building Council, sustainability and energy efficiency has become a top priority across the globe when planning building and infrastructure projects. Although much of this push has come from consumers’ desires for healthier materials within their homes and offices, governmental policies improving environmental regulations have also been key. The transition has been made easier as eco-materials have become increasingly available and cost-effective.
Currently, the construction sector accounts for 39% of global carbon emissions. In all phases of buildings – from construction and renovations to occupancy and demolition – harmful chemicals and pollutants are leached into the atmosphere threatening public health. As a result, the construction sector has extensive direct and indirect impacts on the environment.
To reduce carbon emissions when it comes to your next project, here are some widely available low in embodied carbon or carbon positive materials:
Bamboo
Bamboo is not a wood but rather a fast-growing grass allowing it to be replenished quickly
(generally within 5 years). While trees die when they are cut down for timber, bamboo stalks can
continue growing after being harvested making it a more sustainable option compared to wood
because it continues to sequester carbon as it grows. Bamboo is also known for having high
tensile strength, elasticity, and durability which allows it to last for many years.
Wool
Sheep Wool is a smart choice for building insulation due to its unique ability to sequester carbon and filter other harmful chemicals from the air without the need to off-gas. As a natural and rapidly renewable material, Sheep Wool has the natural ability to manage moisture and retain heat. Sheep Wool Insulation is free from glues and bonding agents allowing it to be composted or reused for other purposes at the end of its life. With an R-value of greater than 4.0/inch, wool has a high thermal performance.
Dense-Pack Cellulose
Dense-pack cellulose insulation is cost-effective and easy to install. Made of shredded paper and fire retardant borate. Although there are claims borate is toxic, it is largely harmless in small amounts and is found in various adhesives and finishes. As insulation, dense-pack cellulose is often made of 80% recycled materials and when installed correctly, it will properly manage moisture and air circulation.
Cork
Made from the outer bark of Cork Oak Trees, Cork insulation is a sustainable and renewable alternative to traditional synthetic insulation. Over the 200 year life of these trees, the bark can be harvested an average of 16 times! As a building material, cork is incredibly durable and highly resistant to temperature fluctuations and moisture.
Hempcrete
Hempcrete is a composite material made from a mixture of hemp hurds, lime, and binding agents. Hemp is a fast-growing plant that naturally sequesters carbon in the stalk and surrounding soil. Traditionally, hemp is used in a variety of commercial and industrial products such as animal feed, clothing, and medicinal CBD. As carbon smart building material, Hempcrete utilizes the byproduct of hemp, the woody core (hurd) to produce the lightweight but durable material to be used in construction and insulation.
Straw Bale
Straw Bale is a smart choice for building insulation because it is approximately 40% carbon by weight. Much like bamboo and hempcrete, straw bale naturally sequesters carbon in the stalk as well as the soil, however, the exact amount of carbon that is sequestered depends on the environment the straw is grown in and the harvesting methods. When properly built and maintained, straw bale in buildings can last for at least 100 years! Naturally fire-resistant and highly insulative, straw bale has an R-value of 1.3 per inch and is extremely cost-effective.
How is this going to change the industry?
Currently, the construction industry accounts for 39% of global carbon emissions (11% of which is attributed to materials). However, by implementing green practices and materials into new construction, there is the potential for significant decarbonization. Meaning the percentage of global carbon emissions attributable to the construction industry is drastically reduced!
As global temperatures continue to rise, sustainable green buildings will grow in necessity. To gauge the sustainability of products and building designs, the following metrics have emerged: LEED, WELL, ASHRAE, GRESB, and Living Building Challenge. Each of which assesses the performance of buildings and materials in terms of eco-friendliness and public health benefits.
Here at AMAST, we are working with suppliers who have the best quality of certified products!