Circular Economy Integration in LEED: A Decade of Materials and Resources Credit Achievement Patterns

Abstract

Previous studies consistently label the Materials and Resources (MR) credit category of the Leadership in Energy and Environmental Design (LEED) as the least attainable, despite its critical role in transitioning to a circular economy (CE). To this end, a long-standing gap exists in understanding the MR credit achievement, especially in LEED v4, which has been in use for nearly over a decade. This paper evaluates the level of CE integration in LEED v4 across 971 US-based certified projects. The study comprehensively analyzed the projects achievement patterns of the five MR credits: Building Life Cycle Impact Reduction (C1), Environmental Product Declarations (C2), Sourcing of Raw Materials (C3), Sourcing of Material Ingredients (C4), and Construction and Demolition Waste Management (C5). Results revealed that the most prevalent point achievement pattern was 0-1-0-1-2 out of a maximum of 5-2-2-2-2 for C1, C2, C3, C4, and C5. C1 and C3 posed significant challenges, with 588 and 601 projects receiving zero points, respectively. Additionally, the study statistically investigated differences in achievement across project groups of different certification levels, space use, and floorspace categories. Findings are further validated through interviews with LEED experts, who emphasized challenges such as additional costs, inadequate project specifications, and delays in engaging LEED professionals. Results align the status of LEED projects with the lower impact end of the reduce, reuse, recycle framework of CE, which is limited to waste management approaches. Research implications stress the need for collaborative efforts across the industry, owners, and policymakers to enhance CE practices within LEED projects. Ultimately, this study advocates for incentivizing building reuse, the integration of optimized life cycle assessments, as well as enhancing material data availability and transparency.