Since the 1990s, Leadership in Energy and Environmental Design standards have guided industry expectations around building efficiency, from energy and water use to waste diversion. In response, stakeholders have refined their ability to optimize performance within a building’s envelope after construction.
Now, LEED v5, the latest version of the green building rating system, emphasizes embodied carbon, the emissions generated by manufacturing, transporting, and installing every single material.
For architects specifying metal, a central part of modern design that is carbon-intensive in manufacturing and transportation, this new standard demands a new level of diligence and data-driven design.
Metal’s enormous carbon footprint
Metal production, particularly for steel and aluminum, is an energy-intensive process.
Steel manufacturing alone is responsible for up to seven percent of global CO2 emissions. While three-quarters of steel pollution comes from burning coal and coke in blast furnaces, another 25 percent is attributed to transporting and installing the materials.
For this reason, under LEED v.5, specifying a metal product without understanding and documenting its carbon impact can jeopardize project certification.
To be sure, with proper material selection and carbon accounting, steel can shift from a primary source of emissions to a critical pathway for lifecycle CO2 reduction.
Its benefits are multifaceted and long-lasting. Metals possess unparalleled durability, longevity, and, most importantly, near-infinite recyclability. A steel beam or an aluminum curtain wall from a building today can be melted down and reformed for a project a century from now with a fraction of the initial energy investment.
Achieving LEED compliance
Architects can follow three key pathways to ensure their steel designs meet the new embodied carbon requirements.
Embrace data-driven specification
The era of generic specifications is over. The new imperative is to actively request and compare Environmental Product Declarations (EPDs) from suppliers for all major steel and aluminum products. This means setting maximum Global Warming Potential (GWP) thresholds in specifications, aligned with benchmarks from LEED and the Carbon Leadership Forum.
Combine data collection with embodied carbon accounting software to track impact, compare suppliers, and document compliance.
Embedding embodied carbon into the building specs allows architects and their partners to document certification requirements and signals a commitment to sustainable procurement, differentiating architects in competitive bids.
Leverage whole-building life-cycle assessment (WBLCA)
LEED v5 awards points for demonstrating reductions in embodied carbon across the entire building, not just individual products.
WBLCA software has become an increasingly powerful tool for architects. Early in the design phase, these tools allow for the modeling of an entire building’s carbon footprint and show how different material choices interact.
Perform these tasks early in the design process to test how different framing systems, cladding options, or structural spans impact the project’s holistic carbon footprint. Additionally, use these outputs to guide value engineering discussions, so overall cost can be accounted for alongside carbon footprint, ensuring both are prioritized without compromise.
Design for reuse
LEED v5 explicitly rewards reuse. Metals are uniquely suited for recycling, repurposing, or modularization without losing structural integrity.
This directly plays to metal’s greatest strength. Specifying metals with high recycled content is the most straightforward way to reduce embodied carbon. However, decisions can be even more granular, such as designing connections to enable future disassembly and reuse.
Documenting a project’s reuse potential in LEED submittals to capture additional credits.
Making embodied carbon a design parameter
LEED v5 is the next iteration of the world’s most widely adopted green building standard. Emphasizing embodied carbon as a pillar of sustainability, LEED v5 pushes architects and project teams to move beyond operational efficiency and confront the full climate impact of material choices from day one of design.
Yes, metal production is carbon-intensive, but metals’ durability, recyclability, and adaptability make them the right fit for many sustainable projects.
To integrate metal materials while achieving LEED v5 certification, embrace data-driven specifications, leverage whole-building life-cycle assessments, and design for reuse.
Put differently, treat embodied carbon as a design parameter as fundamental as cost, aesthetics, or performance. It is the best way to integrate this material without compromise.
Tommy Linstroth is the founder and CEO of Green Badger, a leading SaaS provider simplifying sustainability and ESG in the built industry. Green Badger provides construction teams with software designed to support LEED compliance and ESG reporting. The platform automates documentation and consolidates project data, helping teams manage sustainability requirements more efficiently and reduce the time required for compliance reporting. For more information, visit www.getgreenbadger.com.