Learn How to Read Environmental Product Declarations (EPDs)

Reading Environmental Product Declarations (EPDs) can be challenging. The reports contain technical data, scientific terminology and lifecycle metrics that may be confusing to even experienced professionals. Understanding how to read EPDs is an essential skill for architects, engineers, sustainability managers and procurement professionals who want to make informed, environmentally responsible decisions. With the built environment accounting for nearly 37% of global CO₂ emissions, transparent product-level data is critical. This is where environmental product declarations (EPDs) play a vital role, helping decision-makers compare materials, assess sustainability impacts and align with international reporting standards.

What is an Environmental Product Declaration (EPD)?

An environmental product declaration is a third-party verified document that communicates the environmental performance of a product throughout its life cycle. It is based on Life Cycle Assessment (LCA) methodology (ISO 14040 Series) and follows further strict guidance defined by Product Category Rules (PCRs) and international standards such as ISO 14025 and EN 15804.

In learning how to read EPDs, you can think of the certificate as the sustainability equivalent of a nutrition label: it provides transparent, standardised data on environmental impacts such as global warming potential (GWP), energy use, water consumption and waste generation.

Key features of an EPD:

• Based on quantitative LCA data, with the background LCA performed using the ISO 14040 series of standards.
• Developed in accordance with PCRs, which define how LCAs must be carried out and reported for a given product type.
• Complies with international EPD systems such as the International EPD System or Eco Platform.
• Verified by independent third parties.
• Aligned with regulatory and market frameworks such as EN 15804+A2 in Europe or ISO 21930 in the USA.
• They provide the verified, quantitative data that underpins material credits in green building certification schemes such as LEED (Leadership in Energy and Environmental Design) and BREEAM (Building Research Establishment Environmental Assessment Method).

Learn More: EPDs Explained | Tunley Environmental

Types of EPDs

When learning how to read EPDs, it is important to recognise that there are different types. Each serves a slightly different purpose:

Product-specific EPDs

• Developed for a single product or product type from a specific manufacturer. Offer the highest accuracy for procurement and compliance.
• Example: An EPD for a manufacturer’s concrete block or aluminium window frame.
• Sometimes called a “Type III, product-specific” EPD.
• Product-specific EPDs are sometimes further distinguished as plant-specific (one site), company-average (several sites), or group EPDs (covering a family of similar products, typically reported as weighted averages).

Industry-wide EPDs

• Produced by trade associations or industry groups.
• Represent an average of data across multiple manufacturers.
• Useful for benchmarking, but less precise for specific supplier selection.

Project-specific EPDs

• Internal and non-published EPDs often tailored to a particular construction project.
• Combine several product EPDs to assess the environmental profile of a project,
• or adapt manufacturers verified EPDs by incorporating project-specific data,
• Increasingly used in whole life cycle assessments (WLCA) for large infrastructure.

Third-party verification of EPDs

All EPDs bar project-specific EPDs are independently reviewed and approved by an accredited verifier, ensuring accuracy, transparency, and compliance with the underlaying LCA standards, international EPD standards such as ISO 14025 and EN 15804, and the products respective PCR.

Key points:

• These are the most common type of EPDs.
• They are frequently required in large-scale tender applications and for bidding on government projects.
• In the construction sector, they are typically requested as part of due diligence on material selection and for quantifying Whole Life Carbon Assessments (WLCAs).
• Independent verification helps to reduce the risk of greenwashing.

Understanding which type of EPD certificate you are reading ensures you don’t confuse an industry average with a specific supplier’s performance. It also helps you determine the right type of EPD for a specific project.

How to Read an EPD Certificate

When learning how to read an EPD, it helps to break down the report into sections. Each document follows a broadly similar format, though layout may vary depending on the programme operator such as the International EPD System or Building Research Establishment (BRE). Learn more here on the EPD Creation process.

1. Cover Page and Basic Information

(Sample EPD above shows of corrugated pipe from a Brazilian manufacturer. Source: environdec.com/library)

• Product name and manufacturer: Identifies the product and company.
• Programme operator: The body managing the EPD system (e.g., International EPD System).
• EPD certificate number and validity period: Confirms authenticity and expiry, usually five years.
• Publication date and version: useful when comparing different EPDs.
• Geographical scope: indicates where the EPD is valid (country, regional, or global).

2. Declared Unit (or Functional Unit)

The declared unit is perhaps one of the most important items to take note of when reading in EPD. It is the basis for all environmental results in the EPD. It defines what quantity of product the impacts refer to.

Examples:

• 1 kg of aluminium profile
• 1 m² of installed insulation board, with 20 years reference service life

If the EPD reports a Reference Service Life (RSL), this is also listed alongside the declared unit.

Without understanding the declared unit, you cannot interpret or compare impact tables correctly.

3. Product Category Rules (PCRs)

• PCRs define the rules for carrying out the LCA for a given product group. Ensure that comparisons are fair: all concrete blocks, for example, must be assessed with the same PCR. Always check the PCR reference number and version used in the EPD before comparing products.

4. Life Cycle Assessment (LCA) Stages

Most EPDs divide impacts into standardised modules following EN 15804:

• A1–A3 (Product stage): Raw material extraction, transport, and manufacturing.
• A4–A5 (Construction stage): Transport to site and installation.
• B1–B7 (Use stage): Operational impacts (maintenance, energy use).
• C1–C4 (End-of-life): Demolition, waste processing, disposal.
• D (Beyond life cycle): Reuse, recycling, and recovery potential.

This modular structure allows clear identification of which life stage contributes most to impacts. 

Learn more: Life Cycle Assessment Stages Explained

5. Environmental Impact Indicators

When learning how to read EPDs, one of the most important parts to understand is the section on environmental impact indicators. The values reported here are expressed per declared unit, for each LCA stage.

These indicators are standardised metrics that measure how a product affects the environment across its life cycle, from raw material extraction through to disposal or recycling. Common indicators include:

• Global Warming Potential (GWP) – Greenhouse gas emissions, reported in CO₂ equivalent.
• Ozone Depletion Potential (ODP) – Impacts on the ozone layer.
• Acidification Potential (AP) – Contribution to acid rain.
• Eutrophication Potential (EP) – Nutrient pollution impacts on water.
• Photochemical Ozone Creation Potential (POCP) – Smog formation.
• Resource Use – Demand for renewable and non-renewable primary energy, and material resource depletion.
• Waste flows and output flows – Hazardous/non-hazardous waste, materials for recycling, energy recovery.

These indicators provide a multi-dimensional picture of sustainability, not just carbon footprint. Using these indicators can help professionals compare materials on more than just their global warming potential (GWP) and make better-informed sustainability decisions.

6. Additional Information

The back sections of an EPD usually include:

• Verification Statement: The final part is the verification statement, which features confirmation of the validity of the EPD
• Assumptions and scenarios: Transport distances, recycling rates, and energy mix.
• Limitations: Clear statements on what is excluded (e.g. biodiversity loss, social impacts).
  
  

Using Your EPD Certificate

Knowing how to read EPDs is only the first step. The next step is applying the data to real-world decisions. Here are several ways you can use an EPD certificate:

Procurement and Tendering

EPDs help demonstrate compliance with client requirements, especially for sensitive projects. They also serve as evidence for green public procurement (GPP) in line with EU and UK frameworks.

Building Certifications

EPDs are recognised by many green building certification schemes as evidence within specific credits:

• LEED v4/v4.1: Products with EPDs can contribute to Materials and Resources (MR) credits, with extra points available for product-specific, third-party verified EPDs.
• BREEAM (Mat 01): EPDs feed into life cycle assessment credits by providing verified environmental data for building-level LCA.
• DGNB and HQE: EPDs are accepted as key sources of LCA data to demonstrate performance against environmental criteria.

Carbon Accounting

EPD data can be integrated into corporate carbon accounting (especially Scope 3: purchased goods and services) to support sustainability reporting. EPDs also link seamlessly with LCA software tools (e.g., One Click LCA, eTool) to assess project-wide impacts and building embodied carbon.

Design Optimisation

During early design building phases (e.g., RIBA stages 2 – 4), EPDs enable like-for-like product comparisons that support lower-impact design choices. For example, switching from an average industry EPD to a product-specific EPD may reveal a 15–20% reduction in GWP.

Applying EPDs to decision-making can help organisations meet compliance requirements and gain a competitive advantage in the transition to net zero.

The Bottom Line

Though EPDs can appear complex at first, they follow a linear and standardised system that’s designed to give you a clear picture of the full environmental impact of a product. Knowing how to read EPDs is important for reducing embodied carbon, selecting more environmentally friendly materials and demonstrating compliance with international sustainability frameworks. To learn more about how you can use EPDs in your projects, visit this page.