Circular Economy for Building Materials
NREL is working to minimize waste from building construction by conducting research on new materials, construction, and building durability as well as developing new design principles and modeling tools.
This research aligns with one of NREL's critical objectives.
The building sector is the one of the largest consumers of raw materials and producers of waste in the United States. Production of building materials accounts for a significant portion of the 25% of total energy and 75% of raw materials consumed by the U.S. manufacturing industry. As such, a circular economy for building materials stands to offer significant gains in efficiency, waste reduction, and decarbonization.
NREL's work on developing a circular economy for building materials takes a multipronged approach. One key research area is the development of new materials and advanced construction methods designed to improve building performance and durability while minimizing waste. Carbon-negative building materials provide an avenue for long-term carbon sequestration as well as improved performance and durability. Advanced construction methods incorporate these new materials while reducing overall material consumption and increasing reuse. A second core research focus is gathering industry data and possibly adding life cycle assessments to NREL's building energy modeling tools. This effort is designed to help architects and engineers better understand the impacts of their design decisions.
Investigating New Building Materials
Common building materials, such as concrete and steel, tend to be energy- and carbon-intensive to produce. To combat these issues, NREL has projects underway that explore the potential of wood—a natural, abundant, and renewable construction material with low cost—in building design and construction.
One research effort focuses on building construction using cross-laminated timber as an alternative to reinforced concrete systems. Cross-laminated timber is considered environmentally friendly due to the renewable nature of wood. In addition, research on cross-laminated timber points to its potential to reduce the global warming potential of buildings.
Another research effort has proposed the use of a renewable wood-based thermal energy storage composite, combined with biodegradable phase-change materials. This project is advancing the use of thermal energy storage in buildings, which has shown great promise for reducing energy consumption and shifting loads. For instance, in research funded by the U.S. Department of Energy Building Technologies Office, NREL showed that thermal energy storage in buildings could provide over 70% of grid storage needs, even with 80% of the grid electricity provided by renewable generation.
Reusing, Remanufacturing, and Recycling Building Materials
Another important aspect of building material selection is end-of-life management. A lack of data, methodology, and design integration have hindered efforts to address reuse, remanufacturing, and recycling of building materials in the building design process. A project at NREL aims to address these limiting factors by creating an end-of-life database for building materials and components. In addition, NREL is creating a consistent set of end-of-life standards and protocol as well as tools for design integration.
Developing Advanced Construction and Design Methods
Another major research focus at NREL involves developing advanced construction methods and innovative designs to reduce the waste streams inherent in conventional construction. One such effort is New Iglu—a modular building system that standardizes widely used components to allow system interoperability. Three core technologies make up New Iglu: (1) a super-insulated composite panel, (2) a modular structural frame, and (3) a pressure equalized mounting system. The inherent flexibility of the New Iglu building system allows users to replace, add, or upgrade panels with emerging technologies, reducing waste and allowing for reuse.