By Mary James

Bio-based construction materials have been around and available for decades but not necessarily easily sourced. Today, with concerns about the embodied carbon of buildings on the rise, so is interest in bio-based materials. A new RMI report, Building with Biomass: A New American Harvest, lays out the case for the many environmental and economic benefits of manufacturing building products from upcycled biomass.  

The report, authored by Chris Magwood and Victor Olgyay, along with other RMI staff, details how using building products made from biomass materials that are currently wasted or underutilized can significantly cut into the 55 million tons of embodied carbon emissions generated annually from the construction of new homes in the United States every year. The carbon storage potential from swapping out conventional building materials and replacing them with merchandise made from some of the 1.1 billion tons of underused biomass produced annually is significant; carbon-storing homes can reduce embodied carbon by a whopping 107% over business-as-usual models. 

For readers already convinced that a tradeoff in materials is theoretically a great idea, the report delivers practical guidance in how to go about achieving such carbon-storage goals. Indeed, it’s inspiring to see the range of currently available products that RMI included in its analysis of the embodied carbon impact of replacing typical building products with bio-based products (see Exhibit 5). Looking for substitutes for OSB? The report lists four with EPDs, ranging from straw board panels to gypsum and cellulose panels, and three more with no EPDs. And, that’s just for one commonly used construction material in single-family homes. The report authors chose to focus on this market, because single-family homes represent more than 60% of all newly constructed floor area in the United States. Additionally, custom home builders tend to have more flexibility about trying new products and approaches than do construction teams working on other building types. 

Alongside reluctance to stray from tried-and-true approaches, for most builders and project owners, potential cost increases can be a major stumbling block. Fortunately, the RMI team has not shied away from tackling that concern, pulling product information from building supply and distributor websites to answer such questions as, how does wood fiber batt compare to fiberglass batts or bio-based carpet to vinyl flooring? It turns out many bio-based materials are at or near cost parity with their conventional counterparts (see Exhibit 11). Increasing demand for biomass products will bring economies of scale that in turn should drive down the prices for these carbon-storing products.

But, what’s the business model for driving up demand for bio-based products, one might wonder? Fortunately, the report has that topic covered as well, with a number of case studies featuring firms that have already figured out profitable pathways in this field. Plantd, which produces structural panels made from fast-growing grasses, has entered into a partnership with the long-established home builder D.R. Horton to supply 10 million panels over the next several years. Those panels will sequester 165,000 metric tons of CO2, Plantd estimates, and avert the need for cutting down 1.2 million trees. Other featured companies include Timber Age Systems, Timber HP, and New Frameworks.

These companies are at the cutting edge of what RMI terms the New American Harvest, durably storing millions of tons of carbon while helping to close the housing supply gap and provide new revenue sources to American farmers and foresters. The report grounds this all-around positive economic vision in solid data and ends with a comprehensive list of suggested actions for all stakeholders, from biomass producers to new homebuyers.

Top image is of the Timber Age Systems facility in Durango, Colorado. Photo courtesy of Johnny Rezvani.