How to Use EPD Data to Reduce Embodied Carbon in Construction Projects

Embodied carbon — the CO₂ equivalent emissions locked into a building’s materials and construction process — now accounts for a growing share of the construction industry’s climate responsibility. As buildings become more energy-efficient in operation, the relative weight of embodied carbon increases. For a modern, well-insulated office building, embodied carbon can represent 50% or more of lifetime emissions. EPD data is the primary tool for measuring, comparing, and reducing it.

Understanding what EPD data tells you

Every construction product EPD reports Global Warming Potential (GWP) as one of its core environmental indicators. GWP is expressed in kg CO₂ equivalent per declared unit — per kilogram of steel, per cubic metre of concrete, per square metre of insulation board. This figure represents the climate impact of producing that quantity of material, from raw material extraction through manufacturing.

EN 15804+A2:2019 splits GWP into three components: GWP-fossil (from burning fuels and industrial chemistry), GWP-biogenic (carbon stored in biological materials), and GWP-LULUC (from land use change). For most construction materials — concrete, steel, mineral insulation — the fossil component dominates. For timber products, biogenic carbon accounting significantly affects the result and should be interpreted carefully.

Comparing products using EPD data

The power of standardised EPDs is comparability. If two concrete suppliers both have EN 15804+A2:2019 compliant EPDs covering modules A1–A3, you can compare their GWP-fossil values per cubic metre directly. A difference of 20 kg CO₂e per m³ may seem small, but across a large infrastructure project using tens of thousands of cubic metres of concrete, the difference in total embodied carbon runs into hundreds of tonnes.

This comparison only works under specific conditions. The EPDs must cover the same life cycle modules (usually A1–A3 for materials comparisons). The declared unit must be comparable. And the EPDs must both comply with the same version of EN 15804 — the 2012 version and the A2:2019 revision are not directly comparable because they use different rules and different indicator sets.

Using EPD data in whole-building LCA

The most rigorous approach to embodied carbon in construction is a whole-building life cycle assessment. A whole-building LCA takes the quantities of all major materials (from structural drawings and specifications), multiplies them by EPD data for each material, and aggregates the results across life cycle stages to produce a total embodied carbon figure for the building.

Tools like One Click LCA, SimaPro, and the IESVE Carbon suite can import EPD data directly — either from databases of published EPDs or from manufacturer-provided EPD data files. When EPD data is used rather than generic database values, the results are more accurate and, importantly, more defensible for green building certifications and investor reporting under the EU Taxonomy.

Practical strategies for embodied carbon reduction

Armed with EPD data, design teams have several levers for reducing embodied carbon. Material substitution is the most direct: comparing EPDs from multiple suppliers for the same product type and specifying the lower-carbon option. For structural concrete, specifying a mix with higher supplementary cementitious material (SCM) content — fly ash or ground granulated blast furnace slag — can reduce GWP by 30–50% relative to a standard CEM I mix, and the difference is directly visible in supplier EPDs.

Design optimisation is the second lever: using LCA data to challenge over-specification. Reducing the slab thickness in a concrete frame by 20mm across all floors, or reducing structural steel section sizes where calculations allow, produces embodied carbon savings that EPD-based calculations can quantify precisely.

Material reuse and end-of-life planning are the third lever. EPDs include Module D data on recycling and recovery potential — the net credit from materials that will be recycled at end of life. For steel structures, Module D credits can significantly offset cradle-to-gate impacts and should be factored into whole-life assessments.

From data to procurement requirements

The final step is embedding EPD data requirements into procurement. Increasingly, developers and main contractors in Poland and across Europe are including EPD requirements in material specifications — requiring that structural concrete, rebar, structural steel, and insulation all be sourced from manufacturers with current EN 15804+A2:2019 compliant EPDs, and setting maximum GWP thresholds for key products.

For Polish manufacturers, this shift in procurement is both a challenge and an opportunity. Manufacturers with EPDs can respond to these specifications competitively; those without face disqualification from an increasing share of EU-funded and sustainability-rated projects.