Why site-specific EPDs matter for carbon-smart design decisions
By Brent Trenga, director of sustainability, Kingspan Insulated Panels North America
As architects work to meet increasingly ambitious climate goals, the conversation around embodied carbon has moved from abstract targets to material-level decision-making. Environmental product declarations (EPDs) play a critical role in that shift. Much like a nutrition label, an EPD transparently communicates the environmental impacts of a product across its life cycle, from raw material extraction through manufacturing, use, and end of life.
But for architects trying to meaningfully reduce embodied carbon, not all EPDs offer the same value. The level of detail matters, and in many cases, the difference between an average and a site-specific declaration can influence both design outcomes and carbon performance.
Understanding the spectrum of EPDs
EPDs used in the construction industry generally fall into three categories.
Industry-wide EPDs are developed by trade associations and represent averaged environmental impacts for a broad product category. These declarations are helpful as high-level benchmarks, particularly early in design, but they lack the specificity needed for precise carbon accounting.
Product-specific EPDs provide data for a manufacturer’s product line and are based on life cycle assessment (LCA) data. While they offer more detail than industry-wide EPDs, they are often averaged across multiple manufacturing facilities, which can mask significant variations in energy sources, processes, and supply chains.
Site-specific EPDs represent the most granular option. They are derived from LCAs of products manufactured at a specific facility, capturing the actual impacts associated with that site’s energy mix, production efficiencies, material sourcing, and logistics. For architects evaluating embodied carbon at a project level, this distinction is increasingly important.
Why granularity matters in embodied carbon accounting
Embodied carbon emissions are effectively “locked in” once construction is complete. Unlike operational energy, which can be reduced over time through retrofits or system upgrades, the emissions associated with material extraction and manufacturing are irreversible. This reality places greater responsibility on early design decisions, where material selection has the greatest leverage.
Site-specific EPDs allow project teams to move beyond generalized assumptions and make decisions based on real, verifiable data. For architects pursuing high-performance goals, whether driven by firm commitments, client expectations, or programs like the AIA 2030 Commitment, this level of transparency supports more accurate whole-building life cycle assessments and more defensible design choices.
Applying site-specific EPDs in practice
One of the key benefits of site-specific EPDs is their ability to reveal regional and facility-level differences that can materially affect global warming potential (GWP). Manufacturing plants that use renewable energy, more efficient processes, or lower-carbon raw materials can demonstrate significantly reduced embodied carbon compared to industry averages.
For example, site-specific EPDs for insulated metal panels (IMPs) manufactured at facilities with access to onsite renewable energy or lower-carbon steel supply chains reflect measurably lower GWP values. This enables architects to align product selection with both performance requirements and climate goals, while also considering proximity and regional sourcing.
Site-specific EPDs also support transparency and accountability across the supply chain. Third-party verified, cradle-to-grave declarations provide confidence that reported impacts reflect actual production conditions rather than modeled averages.
Supporting informed, climate-responsive design
As sustainability standards evolve, architects are being asked not just to specify “better” materials, but to demonstrate how and why those materials contribute to lower-carbon outcomes. Programs such as the AIA Materials Pledge and growing client demand for embodied carbon reporting are accelerating this shift.
Site-specific EPDs help bridge the gap between intent and impact. By providing actionable data, they support more rigorous comparisons between functionally equivalent products and help project teams prioritize reductions where they matter most.
Looking ahead
Reducing embodied carbon at scale will require continued collaboration between designers, manufacturers, and policymakers. Transparent data is a foundational piece of that effort. As more manufacturers invest in site-level assessments and emissions reductions, architects gain stronger tools to design buildings that are not only high-performing but climate-responsible from day one.
Explore how site-specific EPDs inform material selection and whole-building life cycle assessments through Kingspan’s real-world project case studies featuring IMPs.
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