What Is an EPD and Why Does It Matter?

An Environmental Product Declaration (EPD) is a standardised, third-party verified document that transparently communicates the environmental performance of a product over its lifecycle. Think of it as a nutrition label, but for building materials - instead of calories and fat content, it declares carbon emissions, resource depletion, and other environmental impacts.

EPDs follow international standards (EN 15804 for construction products in Europe) and are produced using Life Cycle Assessment (LCA) methodology. They cover the product from cradle to gate (Modules A1–A3) at minimum, with many now extending to cover the full lifecycle.

As embodied carbon regulation tightens, EPDs become the primary evidence base for carbon claims. Generic database values (like ICE) provide useful defaults, but project-specific EPDs offer much more accurate data - and regulators increasingly prefer them.

Specifying products with EPDs demonstrates due diligence and enables accurate whole-life carbon assessments. Many green building standards (BREEAM, LEED) now award credits for EPD use.

The key metric in an EPD for embodied carbon is the Global Warming Potential (GWP), measured in kgCO₂e per declared unit. The declared unit varies - it might be per kg, per m², per m³, or per unit (e.g., per brick).

Look for the A1–A3 figure first (product stage), as this represents the manufacturing emissions and is the most commonly reported and compared. If available, review A4–A5 (transport and construction) and the full lifecycle (B and C modules) for a complete picture.

Always check the declared unit carefully when comparing EPDs - a lower GWP number might simply reflect a different functional unit rather than genuinely lower carbon.