July 10, 2025
Much of the groundwork for this post comes from the incredible research and insights produced by RMI. A special shout out to RMI for their leadership in the field, and for charting a path toward a New American Harvest.
Carbon Emissions from the Built Environment:
Believe it or not, buildings are actually a large source of carbon emissions. In 2022, buildings and their construction were responsible for 21% of global greenhouse gas emissions and 37% of energy and process-related carbon dioxide emissions. “Greenhouse gas” is an umbrella term for gasses (such as carbon dioxide, methane, and nitrous oxide) that, when released in excess, contribute to global warming.
These emissions come from either Operational Carbon or Embodied Carbon buckets:
- Operational Carbon – These are greenhouse gasses emitted directly through the building’s day-to-day energy consumption
Direct Emissions – these primarily stem from energy production and consumption on-site, such as burning fossil fuels for air conditioning or heating.
Indirect Emissions – these primarily stem from energy production and consumption off-site, such as purchased electricity generated elsewhere and used within the building
- Embodied Carbon – These are greenhouse gasses primarily emitted throughout a product’s lifetime, from raw material extraction to end of life.
For decades, reducing operational carbon through energy efficiency and renewable energy has been the dominant climate strategy for buildings. And for good reason! Operational carbon emissions make up 75% of building’s total emissions. That being said, researchers expect embodied carbon to jump from 25% to close to 50% by 2050.
As fossil fuels continue to be replaced with cleaner alternatives, we must turn our attention to decarbonizing the materials that go into our built environment. Addressing the embodied carbon emissions throughout the entire lifecycle of a product– from raw material extraction to end-of-life– offers a framework from which we can holistically target the industry’s greenhouse gas emissions.
A Building’s Life Cycle:
A building’s life cycle consists of four stages: the Product Stage (A1-A3), the Construction Process Stage (A4-A5), the Use Stage (B1-B7), and the End of Life Stage (C1-C4). The letters A through C represent the broader category stages, with the following numbers representing specific stages.
A project can assess embodied carbon throughout these stages by conducting a Life Cycle Assessment (LCA), which is a systematic analysis of a material or product’s environmental impacts over its entire life. The LCA results can then be disclosed in an Environmental Product Declaration (EPD), which is essentially a product transparency document that grants consumers access to the product’s environmental impact information. The think tank RMI suggests another way of thinking about EPDs: as nutrition labels that can help guide consumers in choosing the healthiest building materials.
Without a product’s EPD, there is no way of easily understanding a product’s environmental impacts. Let’s take a timber beam for example. One could be sourced from an old growth forest and transported from across the country or even internationally, whereas the other could be Forest Stewardship Council (FSC) certified and transported to the site from a local producer just 50 miles away. They may look identical, but the two timber beams have very different environmental impacts.
Lower Carbon Building Products:
RMI estimates that between 65-85% total embodied carbon emissions occur during the cradle-to-gate scope– remember that this includes Raw Material Extraction (A1), Transport to manufacturing site (A2), and Manufacturing (A3). As a result, many third-party green building certifications ask for EPDs that cover at least a cradle-to-gate scope (A1-A3). This offers an opportunity for Appalachian manufacturers to enter greener markets, using their agency over these processes to directly reduce emissions through internal changes in material sourcing and extraction processes, manufacturing practices, transportation methods, and proximity to resource extraction sites.
Besides specifying lower carbon products, companies can support cleaner materials through a chain of custody model called “book and claim”, which works by having companies pay for the environmental benefits—such as lower embodied carbon emissions—even if they don’t purchase those exact materials. This system lets more companies support cleaner building materials through investment. When more companies do this, it sends a strong message to producers that there’s real demand, and helps them get the money they need to increase their production.
Building Clean offers an extensive database of building products that are more efficient, less toxic, and manufactured in the U.S. by union workers. Click here to access the database, and notice that on the left-side of the screen you can refine your search based on product subcategories and certification levels.
The New American Harvest
RMI offers another opportunity for Appalachian manufactures by what they are calling “The New American Harvest.” Researchers from RMI have been exploring the question: is there a way to transform biomass (which is abundant and rarely used) from forests, farms, and landfills into valuable building materials? RMI’s newly released report, Building with Biomass: A New American Harvest, suggests that the answer is yes.
If 400 million tons of grain straw, hemp fiber, timber thinnings and urban residue, recycled paper products, and more– all of which are available, underutilized biomass in the United States– it would be possible to store 100 million metric tons of carbon dioxide in new residential buildings over 25 years, keep 35 million tons of waste from entering landfills, prevent wildfires, enable healthier, affordable home construction, and create $79 billion in new manufacturing opportunities.
What’s more is that these gleaned biomass inputs can be turned into a variety of useful products.
For example, grain straw can be transformed into straw board panels and chopped straw insulation, hemp can be used for hemp fiber batt and hempcrete, and timber thinnings and urban residue can be utilized for wood fiber batt and board and engineered wood.
Click here to read the Building with Biomass: A New American Harvest report from RMI.
Adaptive Reuse:
Adaptive reuse, which is the process of repurposing an existing building into a new use different from its original purpose, offers another impactful opportunity for the region. Giving new life to a building offers a range of benefits, ranging from economic and environmental to social and cultural (e.g. preserving the cultural identity of a vacant building, reducing energy and material use associated with new construction, and encouraging creative and unique sustainable development). It also eliminates the lost energy associated with building demolition.
Housing rehabilitation and energy efficiency retrofits can also sidestep demolition by improving an already existing home. These practices can increase demand for building products such as efficient windows, doors, insulation, structural timber (depending on the rehabilitation project), low-flow toilets, sinks, primary metal fixtures, etc., all of which Appalachian manufacturers can produce. Residential energy efficiency creates job opportunities and is an entry way for early-career folks to get a foot in the door of the construction sector.
Deconstruction:
Deconstruction is the process of taking apart a building instead of demolishing it, which turns useful materials and products into a pile of unusable rubble. Through deconstruction, the salvaged building parts can be sorted, preserved, and adapted for future use. Designing for deconstruction is a circular, closed-loop concept that calls for products to be designed in such a way that they can be easily taken apart and reused. This could look like installing carpet tiles instead of wall-to-wall carpet, or using batt insulation instead of foam insulation. This way, small sections of the product can be removed and replaced as needed, instead of the entire product going to waste.
By adopting a deconstruction mindset, manufacturers can develop other innovative approaches such as take-back programs and products as “services.” This could look like the manufacturer taking back their product at the end of its life to take apart and reinput into their manufacturing system, and providing the customer with a new product. Ultimately, the goal of the Design for Deconstruction movement is to manage products responsibly at the end of life, and reuse materials in another project or recycle them into a new product in a closed-loop system.
To view the EPA’s Fact Sheets on Designing for the Disassembly and Deconstruction of Buildings, click here.