Biogenic Building Materials: Beneficial for Climate, Health, and the Economy
In recent decades, the search for materials that make homes healthier, energy-efficient, and carbon-efficient has proliferated. Since the passing of the Bipartisan Infrastructure Law (BIL) and the Inflation Reduction Act as a legislative response to the ever-growing climate emergency, a motive has been initiated in the building industry to rapidly amend its environmental impact and the human and environmental health crisis in the United States. With around $350 million funds referenced in section 60112 and 60116 of the Inflation Reduction Act, the Environmental Protection Agency (EPA) is looking to prioritize construction materials related to their carbon labeling program and Environmental Product Declaration (EPD) assistance program. Additionally, the Inflation Reduction Act has granted the General Services Administration (GSA) $2.15 billion to procure low-embodied carbon materials for federal buildings with low-embodied carbon while the U.S. Department of Housing and Urban Development (HUD) has been allocated $837.5 million to fund implementation of low-emission materials in affordable housing projects. With increased incentives and resources aimed at reducing embodied carbon in buildings, a particular genre of materials is gaining traction and catching the eye of many in the green building industry as a part of the solution. Biogenic materials or materials made from biomass (straw, hemp, wood, bamboo, cork, wool, etc.) are under research and are being shown to be a viable alternative to some problematic yet widely used building materials.
To understand the potential impact biogenic materials can have on the climate, we first have to understand the negative environmental impact of other types of building material production. Embodied carbon from building and infrastructure materials accounts for 13% of the 40% of annual global CO2 emissions that the built environment is responsible for. The Architecture 2030 Challenge calls for all new buildings and major renovations to be carbon-neutral by 2030, and for all existing buildings to be carbon-neutral by 2050. How do we turn these goals into practical interventions?
Most of today’s conventional building materials require large amounts of carbon emissions to be created into building products. In contrast, biogenic materials inherently sequester carbon, removing CO2 from the atmosphere during photosynthesis, and storing it for as long as the material is prevented from breaking down and composting. When the amount of carbon sequestered by a building’s materials offsets the project’s embodied carbon, the building becomes a “carbon sink” or “emissions sink”. The Carbon Leadership Forum persists that carbon sinks are crucial to the goal of decarbonization by 2030, and demonstrates that biogenic materials’ photosynthetic drawdown affords an initial reduction in carbon emissions that can have an overall and lasting reduction of a project’s carbon count. In a report, they found that “a sizable reduction (~60%) in embodied carbon is possible in two to three years by bringing readily-available low-carbon materials into wider use.”
In addition to carbon sequestration, other environmental benefits of these building products lower their global warming potential (GWP) and contribute to a more environmentally friendly product. The U.S. Green Building Council defines a rapidly renewable resource as a material that’s able to regenerate itself in 10 years or less. Many biogenic materials can be classified as rapidly renewable including straw, cork, hemp, and bamboo, with the exception of timber. Products made from biogenic materials can also be biodegradable if binders, treatments, or other additives are also biodegradable (no formaldehyde). Annual construction waste is expected to reach 2.2 billion tons globally by 2025 and 23% of the national waste stream is estimated to be construction and demolition waste. In order to sustain and improve the amount of waste construction and demolition accrues in the United States, we need to implement biodegradable or reusable materials into common construction practices.
As the building industry strives to create low-carbon energy-efficient buildings with improved indoor air quality (IAQ), biogenic building materials can play a beneficial role on account of their low toxicity and optimal humidity management properties. Biologically grown fibers and materials are free of engineered toxic chemicals such as PFAS, phthalates, isocyanates, and halogenated flame retardants. These materials have natural fire resistant properties when densely packed into building assemblies, which reduces the need for toxic additives and flame retardants that contribute to indoor pollution. Optimal humidity levels are another important part of healthy IAQ. Many biogenic and mineral based materials—including lime, clay, timber, and bamboo—are hygroscopic, meaning they regulate the indoor environment’s humidity by absorbing and releasing moisture between the materials and surrounding air, allowing excess vapor to pass through the wall system without compromising the material. Furthermore, biogenic materials embrace the liminal space between indoors and outdoors, and can be used as a tool for creating biophilic spaces which provide numerous studied physical and mental health benefits while enhancing our connection to the environment.
The production of biogenic materials into building products can benefit the economy, create new jobs, and provide regional economic opportunities for agriculture, manufacturing, and construction. Manufacturers that partner with and source materials from local farmers could create manufacturing jobs and economic opportunity, notably in rural areas. In construction, emerging biogenic building products can spur employment, training, and education opportunities. Additionally, new building materials that are both healthier for installers and substantially more climate friendly have the potential to draw new interest in corresponding construction trades by attracting talent from younger generations with diverse genders and backgrounds whose values and interests are reflected in a changing construction industry. Indicative of this shift is the recent approval of hempcrete into an appendix in the model U.S. residential building code (joining other biogenic materials such as straw, cob, and rammed earth). Locally sourced biogenic materials can foster job growth and support local economies, thereby strengthening our communities.
Manufacturers of products derived from biogenic building materials are on the rise. New products made of hemp, straw, bamboo, mycelium, and others are being engineered, grown, and made here in the U.S. Here is a list of several U.S. manufacturers of biogenic building materials:
Biogenic and Bio-Based Product Manufacturers in Building Clean database
- Havelock Wool LLC- sheep’s wool insulation
- Gryphon Panels- straw and lumber SIP
- List of cellulose manufacturers
Wood siding manufacturers
- Shakertown 1992 Inc. - cedar shake and shingles, wood shingle siding panels, wood panels and siding
- Timber Products Company- sheathing, architectural veneer plywood, custom wood veneer panels, plywood panels, plywood products
- Cedar Valley Manufacturing- cedar shingle siding
- Pacific Wood Laminates- wood siding, plywood panels used in sheathing, wood products
- Americana by Bingaman- thermally modified wood siding
- Louisiana-Pacific Corporation- engineered wood siding, shakes, and shingles
- Miller Shingle Company LLC- cedar shake and shingle siding
- American Clay Enterprises, LLC- clay and lime plasters
- American Lime Technology (importer)- lime stucco and plasters, lime mortars, bio-composite hemp pre-cast wall cladding systems
- Hempitecture- hemp fiber concrete blocks, precast hemp fiber concrete, hemp fiber batts
Other Biogenic Product Manufacturers
- Hempwood- engineered hemp composite flooring made with soy binder and no added formaldehyde
- Earthaus Plaster- interior and exterior lime plaster
Emerging Biogenic Manufacturers to Watch
Located in Madison, ME, GO Lab is launching their suite of Timber HP products in spring 2023, and will be one of the first US manufacturers of wood fiber insulation in the U.S. Their products are composed mostly of residual softwood chips, a plentiful byproduct of the lumber industry, and include loosefill insulation, rigid boards, and batts. https://www.timberhp.com/
Based in Rockland, ME, Croft manufactures straw insulated SIPs with straw locally sourced from no-till organic farms and wood from Maine based lumber mills with FSC certified lumber.
*While biogenic materials are free of many of the harmful chemicals associated with synthetic materials, products derived from biogenic materials may contain additives or binders that have studied health risks. It is preferred to check with the manufacturer on their ingredient contents, and opt for products with HPDs or Declare labels.