Transitioning to a low-carbon economy requires enabling buyers to evaluate and select products, services, and assets with minimal environmental impact. Achieving this goal depends on access to reliable and standardized environmental performance data, often provided by Environmental Product Declarations (EPDs).

EPDs are comprehensive technical documents that detail the environmental impacts of a product. For those focused on reducing carbon emissions, the most relevant data point in an EPD is the Global Warming Potential (GWP), typically expressed as a numeric value. For instance, if an EPD indicates a GWP of 2.5E-2 for a kilogram of product, this translates to 0.025 kg CO₂e.

While it may seem straightforward to simply choose the product with the lowest GWP, it's important to consider the broader context. Much like the fable of the three little pigs, selecting materials without evaluating their suitability for specific conditions can lead to suboptimal outcomes.

When all other factors are equal, selecting a product with lower manufacturing-related carbon emissions is a sound choice. However, real-world scenarios are rarely that simple. Directly comparing products based solely on their manufacturing impacts can result in unintended consequences, such as:

Frequent replacements: Some materials may require more frequent replacement during the lifecycle of a building.

​Indirect impacts: Certain products may necessitate adjustments in other components (e.g., thicker floor slabs requiring thicker walls).

​Lifecycle maintenance: Products with lower manufacturing emissions may have higher lifecycle impacts due to maintenance or end-of-life processing.

​Energy performance changes: The choice of materials can influence operational energy efficiency through factors like daylighting, heat loss, and thermal capacity.

For accurate comparisons, EPDs should only be used to evaluate products with similar functions and performance characteristics.

When products differ in performance attributes, such as thermal efficiency or thickness, a comprehensive Life Cycle Assessment (LCA) is essential. LCAs evaluate environmental impacts across the entire lifecycle of a building, from manufacturing to disposal, ensuring an accurate comparison of materials.

For example, façade options may vary significantly in operational energy performance. EPDs provide the necessary data on manufacturing impacts, which, when combined with LCA methodology, can reveal the true lifecycle impacts at the building level.

While all EPDs must meet specific standards, their quality can vary. EPDs are verified by third parties and adhere to international standards like ISO 21930, EN 15804, and Product Category Rules (PCRs). These frameworks establish consistent assessment rules, allowing for meaningful comparisons when all requirements are met.

At One Click LCA, we have analysed nearly every construction-related EPD available, integrating the majority into our platform. Our database includes over 250,000 EPDs across more than 100 product types, each benchmarked by carbon performance relative to its category.

Environmental Product Declarations provide vital data for selecting sustainable materials, but interpreting them requires careful consideration of their context and quality. By combining EPD data with LCA methodologies, decision-makers can evaluate products' true lifecycle impacts and contribute meaningfully to a low-carbon future.

At One Click LCA, we are committed to simplifying this process, ensuring that reliable, high-quality data is accessible for your sustainable projects.