5
Building Materials: Desired Future State and Solution Pathways

To provide context for the desired future state of plastics in building materials (shown in Table 5-1), the building materials breakout group summarized current challenges in plastics use in the sector. It highlighted that building materials are currently the second largest sector of plastics consumption. Significant challenges include the flow of construction and demolition (C&D) waste to specific landfills, illegal waste dumping into waterways, and the release and health risks of micro- and nano-plastics from building materials. However, there is a lack of readily available information on which polymers are used in building materials. Existing resources on polymers used in building materials include the Organization for Economic Co-operation and Development and the National Academies of Sciences, Engineering, and Medicine’s 2023 consensus study report Recycled Plastics in Infrastructure: Current Practices, Understanding, and Opportunities.

The group also noted critical considerations for building materials when defining a future state. When designing and selecting plastics-based building materials, tradeoffs in structure, health, safety, and product longevity are important. Life cycle assessments (LCAs) of plastics in building materials have noted environmental benefits that may outweigh the impacts of using other materials. However, the continued use of recycled plastics in building materials can perpetuate plastics waste generation. Unlike packaging and textiles, plastics used in building materials are designed for use on the scale of decades, complicating the consideration of materials recycling and introducing a long-term vision beyond current building owners.

The desired future state of plastics in building materials as described by the group was divided into four distinct segments. First and foremost, the accessibility of building materials to building developers and contractors. Second, the availability of locally sourced and sold building materials in order to design buildings with a lower embodied carbon footprint. In addition, buildings designed with modularity to easily repair, replace, or reuse sections that closely align with circular economy practices. From a

TABLE 5-1 Summary of Desired State and Example Pathways Prepared by the Building Materials Breakout Group

NOTE: This summary from the breakout session reflects the discussion of the group and should not be construed as reflecting consensus of the group.

health and safety standpoint, building materials should be nonhazardous and therefore the environmental impacts should be incorporated into the material selection and building design processes. Fourth, business models of building construction such that material stewardship is carried forward to future owners, developers, or material producers over the product lifetime. Inclusion of building material management and end-of-life disposal could increase efficacy of material stewardship. To facilitate this vision, data on material flow during the construction process could be collected and standardized akin to a building material passport. Technical solutions, education, and training can be leveraged to reduce plastics usage in building construction. Importantly, the breakout group emphasized the need for infrastructure to support community health, wealth, wellbeing, and Indigenous rights.

In the discussion of solution pathways, the group presented multiple policy levers based on the existing regulatory framework in the sector. Options included the addition of building materials to the Global Plastics Treaty, phase-out of materials incompatible with circular practices (e.g., spray foam, vinyl flooring), updates to indoor air quality standards to test micro- and nano-plastics in air released from building materials, and removal of petrochemical subsidies that promote virgin plastics production for building materials. Because most C&D waste goes to private landfills that may not be as regulated as municipal landfills, the group suggested regulations on private landfills to reuse waste materials, install sorting infrastructure, and include lining, water containment systems, and testing for plastic leachates in water.

Because materials selection and building practices are influenced by building codes, the group also suggested updates to create “circular codes” that encourage the use of sustainable materials and installation practices. Updated building codes could also improve building resiliency and ease of disassembly and reassembly. Similarly, the group described the options of creation or modernization of zoning laws that dictate building construction, LEED standards to promote the use of sustainable building materials, and insurance standards that also influence materials use.

Improving the transparency of building material standards and understanding the resulting impacts for both builders and consumers was a focus area of the solution pathways discussion (Table 5-2). In relation to building codes, code updates could require producers to complete health product declarations that outline the health impacts from building materials. Moreover, adding labels to building materials comprised of plastics about the potential release of micro- and nano-plastics could promote awareness of the risks. Other information suggested for disclosure include additives used in materials and the flow of plastic products entering construction, which would require data aggregation and expansion of North American Industry Classification System (NAICS) codes to include recycling reporting. Environmental product declarations and LCAs could be helpful tools to inform construction and building companies on materials selection. These data could also be incorporated into designer databases to better inform builders during the design process.

TABLE 5-2 Summary of Example Enabling Policies and Standards Prepared by the Building Materials Breakout Group

NOTES: This summary from the breakout session reflects the discussion of the group and should not be construed as reflecting consensus of the group. C&D MRF: construction and demolition material recovery facility; KPI: key performance indicators; NAICS: North American Industry Classification System.

To address long-term management of building materials, several policy options can extend materials stewardship. Because buildings are designed to last for long periods of time, extended producer responsibility (EPR) and green systems could be incorporated into the building ownership during construction so that used building materials could be recovered by the original manufacturer or installer and then passed down to the next owner. In addition, if the developer wants sustainable choices, the contract could require general contractors to source sustainable products and then recover materials at end of life. The lease of building materials and a take-back system were mentioned as feasible options. Because most building materials are produced regionally, such production could align with circular principles and therefore be leveraged, although needed improvements in the logistics of building construction leave opportunities for optimization.

In addition to policy and coding updates, the group discussed pathways to promote more sustainable developer choices and consumer behavior. Regulated funding for public awareness campaigns at the county and state levels have been implemented before, including Department of Transportation–sponsored initiatives to educate states on better ways to assess materials and building processes for highways. Construction expositions present opportunities to highlight construction best practices, promote green materials, and share examples of successful projects for building materials disposal such as local C&D material recovery facilities (MRFs).

Regarding the proposed solution pathways for building materials, the group discussed possible audiences in the building materials sector hierarchy who could lead solution implementation. Actions could be taken by subcontractors that install materials, general contractors, and community developers, or the product manufacturer or polymer converters before the materials are produced.