As sustainability targets become increasingly stringent, specifiers are under growing pressure to demonstrate the environmental performance of the materials they select.
The built environment remains one of the largest contributors to global greenhouse gas emissions, with embodied carbon accounting for a significant proportion of a building’s total whole-life carbon impact. While the industry has made considerable progress in reducing operational emissions, attention is increasingly shifting towards the carbon associated with construction products and materials.
At the core of an EPD is a Life Cycle Assessment (LCA), which measures environmental impacts across defined lifecycle stages. This typically includes impacts associated with product manufacture (A1-A3), transport and installation (A4-A5), in-use performance and maintenance (B stages), and end-of-life scenarios (C stages), with potential benefits beyond the system boundary reported in Module D where applicable. and to identify opportunities for carbon reduction earlier in the design process. For architects pursuing schemes such as BREEAM, LEED or other sustainability frameworks, verified EPDs can also contribute towards material credits and broader environmental performance targets.
Beyond compliance, EPDs support more informed conversations between manufacturers, architects, contractors and clients regarding material Embodied carbon refers to the greenhouse gas emissions associated with a construction product throughout its lifecycle. This includes raw material extraction, transportation, manufacturing, installation, maintenance, replacement and end-of-life processing or disposal. Unlike operational carbon, embodied carbon is effectively locked in once a product has been manufactured and installed. Consequently, architects and specifiers play a critical role in reducing upfront carbon impacts through material selection and design optimisation.
EPDs provide transparent and impartial environmental data that must be assessed in the wider context of the project’s requirements.
Embodied carbon can represent 40-70% of total emissions across a new low-carbon building’s lifecycle, particularly as operational energy demands fall in line with net-zero design principles. This is why decisions made during the design stage carry greater long-term environmental significance than ever. To support this process, Environmental Product Declarations (EPDs) provide independently verified environmental data that enables meaningful assessment of construction materials before specification decisions are finalised.
WHAT IS AN EPD?
An EPD is a standardised, third-party verified document that communicates the environmental performance of a product over its lifecycle. EPDs are developed in accordance with internationally recognised standards, including ISO 14025 and EN 15804, helping to ensure consistency, transparency and comparability across the construction sector.
An EPD does not simply report carbon emissions alone. It can also include a range of environmental indicators such as Global Warming Potential (GWP), resource depletion, water consumption, waste generation, acidification and eutrophication potential, alongside secondary material and recycled content. The data is compiled using Product Category Rules (PCRs), which establish a consistent methodology for assessing products within the same category. This standardised approach allows architects and sustainability consultants to make more informed product comparisons during the specification process.
WHY EPDS MATTER
As whole-life carbon assessment becomes increasingly embedded within planning policy, certification schemes and client requirements, access to robust environmental data is becoming critical for project teams.
EPDs enable architects to quantify the embodied carbon impacts of specified materials and incorporate this information into lifecycle carbon assessments, that are aligned with standards such as the RICS Whole Life Carbon Assessment for the Built Environment and the UK Net Zero Carbon Buildings Standard.
Importantly, EPDs provide transparency at a product-specific level rather than relying solely on generic industry datasets. This allows design teams to make more accurate calculations when using building lifecycle assessment tools performance, durability, circularity and long-term environmental impact.
CONSIDERATIONS WHEN INTERPRETING EPDS
While EPDs are an important decision-making tool, they should not be interpreted as a standalone sustainability rating or environmental endorsement. Instead, they provide transparent and impartial environmental data that must be assessed within the wider context of project requirements and design priorities.
Direct comparison between products is only valid where EPDs are produced using the same Product Category Rules, functional units, lifecycle boundaries and LCA modelling methodologies. Differences in declared units, assumptions, or lifecycle scope can otherwise lead to misleading conclusions.
Architects should ensure that EPDs are third-party verified, produced to the latest version of EN 15804, and based on equivalent lifecycle stages and system boundaries. EPDs should be current and representative of the manufacturing process being assessed.
For manufacturers such as wienerberger, providing EPDs with robust environmental data supports more informed decision-making across the supply chain while helping architects and specifiers deliver buildings with lower whole-life environmental impact. www.wienerberger.co.uk