Building with Biomass 101: Turning Waste into Worth
High embodied carbon, a housing shortage, and billions of tons of wasted biomass reveal a missed opportunity to build smarter and cleaner.
The problem
The US housing and construction sectors are at an urgent crossroads. Each year, building new homes generates an estimated 55 to 80 million tons of embodied carbon emissions — roughly equivalent to the total annual emissions of entire countries like Norway, Hungary, and Austria. At the same time, the country is grappling with a severe housing shortage, with a deficit estimated between 1.5 and 7.3 million homes.
Yet while emissions rise and demand grows, an overlooked opportunity is : the United States produces over 1.1 billion tons of underutilized biomass every year from farms, forests, and landfills, much of which currently has little to no market value and, in many cases, poses environmental risks when left to decompose or is burned.
Our latest report, Building with Biomass: A New American Harvest, shows how this trio of challenges — high embodied carbon, a housing shortfall, and underused biomass — sets the stage for a new approach to climate-smart, resource-efficient building.
The opportunity
One of the most effective ways to reduce embodied carbon is to use bio-based building products that store more carbon in their raw materials than they emit during production, effectively turning these products — and the buildings they create — into carbon sinks.
Rather than extracting new raw materials solely for construction, we can repurpose more than 400 million tons of existing biomass waste — including grain straw, corn stover, husks/shells, and even sewage sludge — into durable, high-performance building products like insulation, structural panels, flooring, and concrete additives.
Unlike many carbon removal solutions still in development, biomass building products are already being commercially manufactured in the United States and globally. They are cost-competitive with traditional materials and ready to scale across the housing market.
How bio-based materials reduce embodied carbon
1: Plants absorb carbon from the atmosphere
Bio-based building materials are made from plants like straw, hemp, flax, and cellulose. As they grow, these plants absorb carbon from the atmosphere through photosynthesis, locking it into their biomass. The 1.1 billion tons of plant-based biomass identified in this study draw down approximately 1.8 billion tons of carbon emissions, almost half of all emissions produced in the country. But under business as usual, most of that carbon is quickly re-emitted when plants decompose, burn, or are digested by animals.
2: Bio-based materials require less energy to produce than conventional materials
Conventional building products made from minerals or petrochemicals require resource-intensive industrial processes that emit large amounts of carbon before the product ever reaches a building. In contrast, bio-based materials are made from upcycled or minimally processed biomass, requiring far less energy to produce. When the carbon stored in the plant outweighs the emissions from manufacturing, the result is a net-negative product — one that removes more CO₂ than is required to make the product.
3: Swapping out high-carbon materials for carbon-storing alternatives reduces embodied carbon
Substituting standard materials with bio-based alternatives like hempcrete insulation, strawboard partition walls, or biochar concrete aggregate leads to a dramatic reduction in embodied carbon. This is because these materials lock carbon into a building instead of releasing it into the atmosphere through decomposition or burning. If enough carbon-storing products are used in a building, the whole building can have net negative emissions, effectively acting as a carbon sink.
4: Placing bio-based materials strategically can keep carbon out of the atmosphere for decades or centuries
All building materials have a finite lifespan, but they are generally long-lived products, often lasting 50 to 100 years or more — especially when used in protected areas like walls, insulation, and floors. During that time, the carbon captured by plants remains locked away, keeping it out of the atmosphere. Even as some carbon is eventually released when materials degrade or are removed, those emissions are small relative to the total carbon stored across the growing stock of buildings over time. And as reuse, recycling, and composting infrastructure improves, end-of-life emissions can be reduced even further.
What we studied: real products, real homes, real impact
The Materials
For our analysis, we selected bio-based building products that are factory-produced either in the United States or globally with underutilized American biomass as the feedstock. To be included, each product needed an Environmental Product Declaration (EPD), a third-party verified document reporting on emissions and carbon storage associated with the product. The feedstock included hemp, recycled paper and cardboard, timber thinnings, grain straw, and more. The specific products we selected have a wide range of uses in a home, from insulation to partitions to flooring.
The Findings
Focusing on new single-family home construction — which accounts for 60% of all new buildings in the United States — we modeled 40 of the most commonly built single-family homes, according to census data. For each house, we compared a business-as-usual scenario with one where carbon-storing bio-based materials replaced conventional products. The difference was profound: conventional construction emits 28.9 million tons of CO₂e each year, while switching to bio-based materials could instead remove 27.7 million tons — turning homebuilding from a major source of emissions into a powerful part of the solution.
Even under modest adoption, the impact adds up fast. If just 25 percent of new homes used bio-based products by 2050 we could store a stunning 100 million tons of carbon — equivalent to the tailpipe emissions of 21 million cars. At 75 percent uptake, that total jumps to 300 million tons of carbon storage — over 160 times the amount of carbon removal achieved in the market today.
This potential is not just theoretical; it’s practical. Many of the materials modeled in this study are already being manufactured and installed, and they work within current building practices. But unlocking their full potential hinges not only on performance but also on affordability and access.
Our cost analysis found that although bio-based products haven’t yet reached full economies of scale, at least one option in each of the seven product categories studied was cost-comparable to conventional materials. That means builders today can choose carbon-storing products without increasing costs, making it possible to build better without pricing people out.
A transformation waiting to happen
Upcycled biomass offers far more than emissions reduction. With over 400 million tons of available underused biomass generated annually in the United States, there is ample raw material to support a new era of bio-based building products. If scaled, this industry could help pull millions of tons of carbon out of the atmosphere, unlock tens of billions of dollars in economic activity, and create tens of thousands of domestic jobs, particularly in rural communities that need them most.
But realizing this vision will require coordinated action: farmers and foresters supplying feedstocks; manufacturers producing at scale; builders and designers choosing low-carbon materials; and policymakers enabling innovation through standards, incentives, and investment. The pieces are in place — now it’s time to connect them so we can build smarter, cleaner, and more equitably.
Read Building with Biomass: A New American Harvest to learn more.
