4. How to Read an EPD

Opening an Environmental Product Declaration for the first time can be overwhelming. You’ll see tables of numbers with unfamiliar units, references to standards you’ve never heard of, and technical terminology that assumes you already know what everything means. But EPDs follow a standardised structure, and once you understand that structure, reading them becomes straightforward.

This guide walks through what you’ll actually see when you open an EPD and how to extract the information you need. Whether you’re an architect comparing insulation options, a procurement manager evaluating suppliers, or a manufacturer checking competitor declarations, understanding EPD structure helps you use the data effectively.

Where to Find EPDs#

Before you can read an EPD, you need to find one. Programme operators maintain public registries where you can search for published EPDs. The major registries include:

The International EPD System (environdec.com) hosts thousands of EPDs from manufacturers worldwide. IBU (ibu-epd.com) focuses primarily on German and European construction products. EPD Norge, EPDItaly, and other national operators maintain regional registries.

Most registries let you search by product type, manufacturer, or keywords. Search results show the EPD title, manufacturer, publication date, and validity period. Click through to download the actual PDF document.

Construction product EPDs also appear in tools like Bionova One Click LCA and other building assessment platforms. These tools integrate EPD data for direct use in building-level calculations.

The Document Header: Basic Identification#

Every EPD starts with essential identifying information. Look at the first page and you’ll find:

The product name and description tells you exactly what product this declaration covers. “Product X insulation board, density 30 kg/m³, thermal conductivity 0.035 W/mK” specifies the product more precisely than marketing names.

The manufacturer details identify who makes the product and often which manufacturing sites the EPD represents. Some EPDs cover single facilities. Others represent industry averages or multiple sites.

The declared unit or functional unit specifies what quantity of product the environmental data describes. Construction products typically use declared units (1 kg, 1 m², 1 m³) rather than functional units. This unit is crucial because all the environmental impact numbers relate to it.

The EPD registration number provides the unique identifier within the programme operator’s registry. This number lets you verify you have the current version and find the EPD again later.

The publication date and validity period tell you when the EPD was issued and when it expires. Most EPDs are valid for five years. Using expired EPDs for decision making is questionable because the product or manufacturing process may have changed.

The programme operator and logo identify which EPD system produced the declaration. Recognising programme operators helps you assess credibility and understand which rules the EPD follows.

Check these basics first. Ensure you have the current version for the specific product you’re evaluating. An expired EPD or one covering a different product variant wastes your time.

Section 1: Product Information and Scope#

After the header, EPDs typically present detailed product information.

Product composition lists major materials and components. A concrete EPD might specify cement content, aggregate types, admixtures, and supplementary cementitious materials. This composition helps you understand what drives environmental impacts.

Some EPDs must disclose substances of very high concern (SVHC) if they exceed regulatory thresholds. This satisfies chemical regulation requirements and informs users about potentially problematic materials.

The reference service life states how long the product is expected to perform in typical applications. A roof membrane might claim 30 years. A paint system might specify 15 years. This matters for calculating replacement intervals in Module B use stage assessments.

Technical performance data describes physical properties relevant to function. Insulation EPDs report thermal conductivity. Structural products report strength characteristics. Cladding shows fire performance. This technical context helps you understand whether products are actually comparable or serve different functions.

Some EPDs include installation guidance, maintenance requirements, or end-of-life recommendations. This information supports scenario development for use and disposal stages.

Section 2: The Product Category Rules Reference#

Every EPD states which PCR it follows. This section might seem like bureaucratic detail, but it’s critical for comparability.

The PCR reference includes:

PCR title and version number identifying the specific rules followed. “PCR for Wood and wood-based products, EN 16485:2014” tells you this EPD follows the European standard for timber products.

The PCR publication date matters because PCRs update. An EPD following PCR version 2.0 from 2015 may not be directly comparable to one following version 3.0 from 2020 if methodology changed.

The programme operator that issued the PCR confirms which system’s rules apply. PCRs from different programme operators for the same product category may differ subtly, affecting comparability.

When comparing EPDs, check they follow the same PCR or compatible PCRs. EPDs following different PCRs for the same product type might not be comparable due to methodology differences.

Section 3: LCA Information and Methodology#

This section documents how the environmental assessment was conducted. For technical verification, this matters enormously. For practical product selection, you might skim it but should understand the key elements.

System boundaries state which life cycle stages are included. EN 15804 construction EPDs now require Modules A1-A3 (production), C1-C4 (end of life), and D (benefits beyond system boundary) as minimum. Some include additional use stage modules.

Understanding which modules are included matters for comparison. An EPD covering only A1-A3 isn’t comparable to one covering A1-A3 plus C and D unless you compare only the matching modules.

Data sources and quality describe where data came from. Primary data means the manufacturer measured actual production. Secondary data means generic database information was used for background processes or supply chain elements.

EPDs should state what percentage of impacts comes from primary versus secondary data. Higher primary data percentage generally means more representative results for that specific product.

Database and version identifies which LCA database provided background data. Ecoinvent 3.8, GaBi databases, and others have different data quality and coverage. For detailed comparison, matching databases helps but isn’t always necessary.

Allocation rules explain how environmental impacts were divided between co-products or recycled materials. Different allocation approaches can significantly affect results. The PCR specifies allowed methods, but understanding what was done helps interpret results.

Cut-off criteria state if anything was excluded from the assessment. ISO requirements allow excluding processes contributing less than 1% of mass or energy if they’re also less than 1% of environmental impact. Most EPDs aim for over 99% mass coverage.

Impact assessment methods identify which characterisation factors were used to calculate environmental impacts. EN 15804+A2 mandates specific methods from the European Commission Joint Research Centre. Other EPDs might use TRACI, CML, or ReCiPe methods.

Skim this section to verify the EPD was done properly. If you see worrying gaps (very low primary data percentage, major exclusions, outdated databases), treat results cautiously.

Section 4: Environmental Impact Results – The Core Data#

This is what you came for: the actual environmental impact numbers. EPDs present results in tables organised by life cycle modules and impact categories.

The table structure shows modules in columns (A1-A3, A4, A5, B1-B7, C1-C4, D) and impact categories in rows. Each cell contains a number representing that module’s contribution to that impact category, expressed per declared unit.

A typical row might read:

Global Warming Potential (kg CO₂e): A1-A3: 450 | C1-C4: 25 | D: -180

This tells you production generates 450 kg CO₂e per declared unit, end of life adds 25 kg, and recycling benefits credit 180 kg.

Module A1-A3 (product stage) typically dominates for manufacturing-intensive products. These modules cover raw material extraction, transport to manufacturer, and manufacturing itself. For materials like steel, concrete, or glass, this is where most climate impacts occur.

Modules B1-B7 (use stage) matter for products that require maintenance, replacement, or consume energy in use. Insulation’s operational energy savings appear here. Components needing regular replacement show impacts in B4.

Modules C1-C4 (end of life) cover deconstruction, transport to disposal, waste processing, and final disposal. Products requiring special handling show significant impacts here. Easily recycled products show lower impacts.

Module D (beyond system boundary) shows potential benefits from recycling, reuse, or energy recovery beyond the product system. This module is controversial because it credits future benefits. Some users include it in comparisons, others exclude it. Understanding Module D explains the nuances.

Not all modules appear in every EPD. If use stage impacts are negligible, B modules might be empty or omitted. If end-of-life data is unavailable, C modules might state “not assessed” rather than showing numbers.

The impact categories listed in rows cover multiple environmental concerns:

Climate change (kg CO₂e) measures greenhouse gas emissions. This gets the most attention and is usually the largest number.

Ozone depletion (kg CFC-11 eq) relates to substances that damage the stratospheric ozone layer. Often a very small number because ozone-depleting substances are heavily regulated.

Acidification (kg SO₂ eq or mol H⁺ eq) measures emissions that cause acid rain, damaging forests and aquatic ecosystems.

Eutrophication (kg PO₄ eq or mol N eq) addresses nutrient pollution that causes algal blooms in water bodies.

Photochemical ozone creation (kg NMVOC eq or kg ethylene eq) relates to ground-level ozone and smog formation.

Resource depletion indicators track consumption of minerals, fossil fuels, or other finite resources.

Water consumption (m³) quantifies water use across the life cycle.

Additional indicators might include particulate matter emissions, land use, various toxicity categories, and others depending on the EPD standard.

Understanding these impact categories in detail helps you interpret whether numbers are significant and how different products compare across multiple environmental dimensions.

Units matter enormously. Make sure you’re comparing the same units. If one EPD reports per kilogram and another per square metre, you need to convert using product density or thickness before comparison makes sense.

Section 5: Additional Environmental Information#

Beyond the core impact tables, EPDs often include additional information:

Resource use tables report consumption of renewable and non-renewable materials, primary energy, and water. These aren’t environmental impacts themselves but they provide context.

Waste generation data shows how much waste was produced and how it was treated (recycled, incinerated, landfilled).

Output flows might list specific pollutants or substances released to air, water, or soil.

Scenarios and additional technical information document assumptions made for life cycle stages. Transport scenarios state distances and modes. End-of-life scenarios specify recycling rates or disposal methods. Use stage scenarios define maintenance intervals or replacement schedules.

These scenarios are crucial for understanding results. Module C showing low impacts might assume 95% recycling. If actual recycling rates are lower, real impacts would be higher. Module D showing large benefits assumes markets exist for recycled materials. If those markets collapse, benefits don’t materialise.

When comparing EPDs, check that scenarios are reasonable and comparable. An optimistic recycling scenario versus a pessimistic one could explain seemingly different end-of-life impacts.

Section 6: References and Verification#

The final section provides documentation and credibility information.

References list the PCR, LCA standards followed (ISO 14040/44, EN 15804), impact assessment methods, and databases used. This documentation enables verification of methodology.

The verification statement confirms that an independent verifier reviewed the EPD and underlying LCA. The statement identifies the verifier, states that the EPD follows the PCR and ISO standards, and provides a date.

Check who verified the EPD. Recognised verification bodies with relevant expertise provide stronger assurance than unknown verifiers. The verification date should be close to the publication date.

Contact information for the manufacturer and programme operator lets you request additional information or clarification if needed.

Reading for Different Purposes#

How you read an EPD depends on why you’re reading it.

For product comparison, focus on the impact results tables. Check that EPDs follow compatible PCRs, include the same modules, and use comparable scenarios. Compare impacts across the categories that matter for your decision. Remember that comparing EPDs requires more nuance than just looking at the biggest number.

For green building certification, verify that the EPD meets the certification scheme’s requirements. Check the programme operator is recognised, verification was completed, and the EPD is current. Some schemes have specific requirements for module coverage.

For supplier evaluation, review the methodology section to understand data quality. High primary data percentage suggests accurate representation. Check when the EPD was published and whether it covers the specific product variant you’re buying.

For understanding environmental profile, look at which modules dominate impacts. If production (A1-A3) dominates, manufacturing improvements matter most. If use stage dominates, operational performance drives overall impact. If end of life shows benefits, design for recycling is working.

Common Pitfalls When Reading EPDs#

Don’t assume larger numbers are worse without considering units. 450 kg CO₂e per tonne is different from 450 kg per square metre. Convert to common units before comparing.

Don’t compare EPDs from incompatible PCRs or programme operators without checking methodology alignment. Subtle differences can make results non-comparable despite similar products.

Don’t ignore Module D or treat it the same as other modules. Module D sits outside the system boundary and represents potential future benefits. Some users include it, others don’t. Be consistent in your approach.

Don’t forget that EPDs represent specific products at specific times. An EPD from 2019 might not represent current production if the manufacturer improved efficiency. An EPD for one product variant might not represent the whole range.

Don’t overlook impact categories beyond climate change. A product with low carbon might have high acidification or resource depletion. Multiple impacts matter for comprehensive assessment.

Building EPD Reading Skills#

Reading your first few EPDs takes time as you learn the structure and terminology. After reviewing several EPDs in a product category, patterns emerge. You’ll quickly spot which module dominates, which impact categories matter most, and how products differ.

Start with EPDs for products you know well. Understanding the physical product helps you interpret why certain life cycle stages or impacts are significant. A heavy product requiring long transport will show high A2 impacts. A product requiring frequent maintenance will show B2 impacts.

Compare several EPDs within the same category following the same PCR. This shows the range of performance and helps you understand whether a particular result is typical or unusual.

Look for EPDs from reputable manufacturers in your sector. Well-documented EPDs with transparent methodology provide better learning material than minimal declarations with sparse information.

When You Need Help#

Some EPDs are complex enough that expert interpretation helps. Products with unusual use patterns, complex end-of-life scenarios, or multiple functional attributes may require deeper analysis than straightforward product comparison.

If you’re making high-stakes procurement decisions, using EPDs for regulatory compliance, or evaluating products for major projects, consider engaging environmental consultants who specialise in EPD interpretation. The cost of expert review may be small compared to the value of getting the decision right.

For learning purposes, programme operator guidance documents often provide examples of how to read EPDs in their system. These guides show real EPDs with annotations explaining each section.

Next Steps: Deeper Understanding#

Reading an EPD is a skill. This guide covers the practical mechanics, but deeper understanding requires exploring what the numbers actually mean. Understanding EPD modules explains the life cycle stages in detail. Understanding impact categories covers what different environmental indicators measure and why they matter.

Comparing EPDs addresses when and how comparison is valid. Spotting quality EPDs helps you evaluate whether a declaration is well-done or questionable.

The goal isn’t becoming an LCA expert. The goal is using EPD data effectively to make informed decisions about products, specifications, and procurement. Understanding how to read EPDs opens that data for productive use rather than leaving it as incomprehensible technical documents that collect digital dust.