Going the Way of T-Rex: Life Cycle Waste and Emissions in Construction Material Manufacturing
BREX Project Targets Dramatic Cuts in Energy, Materials, and Emissions
Aug. 18, 2021
More than 60 million years ago, the giant predatory dinosaur Tyrannosaurus rex, or T. Rex, devoured nearly everything in sight and wreaked havoc on the Earth. Now, researchers from the U.S. Department of Energy’s National Renewable Energy Laboratory (NREL) are developing strategies to prevent construction from gobbling up resources with BREX—shorthand for Building Materials’ Reduce, Reuse, and Recycling. While these measures can never make construction waste and emissions extinct, researchers are confident BREX can trigger deep cuts in consumption and pollution.
Construction activity is booming, driving demand for steel, aluminum, cement, glass, insulation, and wood. Production of these and other building materials accounts for a large portion of the 25% of the total energy and 75% of the raw materials consumed by the U.S. manufacturing industry, in addition to depleting natural resources and polluting the environment. While the construction industry has adopted increasingly sustainable practices, until now it has lacked the data and tools to most effectively assess how early material and design decisions affect the options for what happens to those materials once buildings and their components reach end of life (EOL).
The REMADE Institute recently awarded NREL and its partners $1.4 million to address these needs with the BREX project. The team is targeting annual 120% improvements in the energy efficiency of manufacturing building materials, 12% reductions in associated greenhouse gas emissions, and 7% increases in the quantity of reused and recycled material. The BREX strategy combines EOL data, whole-building life cycle assessment, computer-aided design (CAD) tools, and user-friendly interfaces for a cradle-to-cradle approach to building construction.
“Today’s building design professionals are getting serious about minimizing their industry’s carbon footprint,” said NREL Communities and Urban Science Group Manager and BREX Principal Investigator Michael Deru. “The BREX concept will give them the tools to dramatically slash material waste and pollution—which will ultimately benefit the industry with increased productivity and profit margins.”
Expert input from architects, engineers, contractors, material suppliers, building owners, policymakers, and other industry, academic, and government partners will help identify research priorities and solution feasibility. Organizations including Skidmore Owings & Merrill, Building Transparency, and the University of Washington’s Carbon Leadership Forum have already signed on as BREX partners.
Cradle-to-Cradle Strategies and the Circular Economy
Today’s forward-thinking design professionals look at each building as a system of material and component subassemblies with integrated life cycle design workflows. The success of BREX depends heavily on weighing EOL factors at the earliest design stages—such as choices of materials and component assembly methods—to minimize the life cycle impacts.
However, even the most progressive designers often wait until too late in the process to consider these issues, limiting the potential benefits. Or else, they have difficulty accessing the data required to make informed decisions.
Unlike more traditional cradle-to-grave methods of evaluating life cycles, which only factor in stages from production through disposal, cradle-to-cradle analysis looks at how to effectively recover materials, allowing them to lead multiple lives. Building design professionals can rely on the integrated Design for BREX process to consider construction materials’ EOL earlier, while still using familiar design and assessment tools. BREX also takes into account subprocesses such as disassembly, sorting, inspection, and collection.
“This shifts the previous take-make-dispose approach to a circular economy of make, use, reduce, reuse, and recycle,” said NREL Communities and Urban Science Research Engineer and BREX Project Lead Ankur Podder.
A circular economy creates a closed-loop supply chain, extending the lifespan of materials, components, and products, while reducing waste, conserving resources, and boosting efficiency. This can help deliver construction supplies that are manufactured using less raw material and energy, last longer, and stay out of landfills.
For example, following the cradle-to-grave model, construction waste makes up about 30% of the solid waste stream, with 90% of that construction waste attributed to EOL demolition. Over the next five years, the BREX team hopes reuse and upcycling at scale will be able to divert as much as 30% of those materials from the waste stream.
In turn, this reuse and recycling could save 150% of energy needed to produce materials and components from scratch, as well as reduce greenhouse gas emissions by 30%. Current BREX efforts focus on structural materials (steel, concrete, lumber, and polymer) and enclosure materials (asphalt, drywall, fiberglass insulation, glass, and aluminum).
BREX’s open-access collection of validated EOL data on high-impact building construction materials, widely disseminated methodology for analyzing material flows and trade-off effects, and user-friendly interfaces with standard environmental product declaration tools such as EC3, CAD tools such as AutoCAD, and whole-building life cycle assessment tools such as One Click LCA will allow manufacturers and design professionals to make decisions that consider the entire material value chain.
Wide-Reaching REMADE Research
REMADE selected for negotiation 24 projects worth a total of $43 million in a competitive process that established the BREX project. While NREL is leading the BREX project, the laboratory is collaborating with other partners on two other projects selected in this round for REMADE funding to help reduce energy consumption and increase U.S. manufacturing competitiveness:
- Analyzing and designing alternatives for recycling, reusing, or replacing nylon-based sheet molding composites for barrier film (led by Ohio State University)
- Diverting mixed polyolefins from municipal solid waste for reuse as feedstocks for automotive and building applications (led by Michigan State University)
In addition, the laboratory is partnering on two other REMADE projects that are already underway. One project is focused on designing high-efficiency solar modules that can be economically recycled, recovered, remanufactured, and/or reused. Another project involves cost-effective techniques to break down multilayer polymer films suitable for upcycling into higher value products.
A public-private partnership established by the U.S. Department of Energy, the REMADE Institute funds research and development for significant reductions in energy use and carbon emissions associated with industrial-scale production and processing of materials. NREL scientists and engineers are developing advanced materials and processes to improve the sustainability of manufacturing a broad range of products.
The circular economy and supply chain analysis are key focal points in the laboratory’s vision for a widespread transition to renewable energy and a healthier, cleaner planet. Eventually, the NREL team envisions incorporating other supply chain tools from sectors beyond the construction industry, such as the Materials Flows through Industry tool, which models energy and materials inputs from initial manufacturing stages through final production stages.