Not all EPDs deserve equal trust. Some contain rigorous, verified data based on measured production processes. Others rely on generic estimates and outdated information. Learning to distinguish quality EPDs from questionable ones protects you from poor decisions.
The difference matters because EPDs influence product selection, certification credits, and ultimately building performance. Using a low-quality EPD means basing decisions on unreliable data. This article gives you practical criteria to assess EPD quality quickly.
Start with the Basics: Verification and Standards
Before diving into methodology details, check whether the EPD meets fundamental requirements.
Programme Operator
Every legitimate EPD identifies its programme operator in the header. This organisation manages the EPD scheme, oversees verifiers, and maintains standards. Recognised programme operators include EPD International, IBU (Germany), BRE (UK), UL Environment (USA), and EPD Norge (Norway).
If the EPD doesn’t clearly state a programme operator, or cites an organisation you’ve never heard of, investigate further. New regional programmes do emerge, but established operators have proven track records.
Programme operator websites list all published EPDs. You can verify the EPD actually exists in their registry. This catches fake or altered documents.
Verification Statement
ISO 14025 requires independent verification. The EPD must state who verified it and when. Look for the verification statement, usually near the end of the document or on the front page.
The statement should name the independent verifier, their qualifications, and confirmation that the EPD conforms to ISO 14025, the PCR, and programme instructions. Vague statements like “internally reviewed” don’t meet the requirement.
For business-to-consumer EPDs, third-party verification is mandatory. Business-to-business EPDs can use internal or external verification, but it must be independent. The verifier cannot have created the EPD or work directly for the manufacturer on EPD development.
Standards Compliance
The EPD must reference which standards it follows. For construction products, this typically includes:
ISO 14025 (Type III environmental declarations) ISO 14040 and 14044 (LCA principles and requirements) EN 15804 (European construction products standard)
Regional variations exist. Some countries use ISO 21930 instead of EN 15804. North American EPDs might reference ISO 21930 or regional PCRs. The specific standard matters less than confirming that a recognised international standard underpins the work.
PCR Reference
Product Category Rules define how EPDs are created for specific product types. The EPD must cite the PCR number, version, and programme operator managing it.
Check the PCR is current and appropriate for the product. A concrete EPD following a steel PCR indicates problems. The PCR version matters because updates change methodology. Using an outdated PCR doesn’t automatically invalidate the EPD, but raises questions about currency.
Publication Date and Validity
EPDs typically remain valid for five years from publication. Some manufacturers update EPDs before expiry to reflect improvements or maintain relevance. After five years, EPDs can extend for another five years if no significant process changes occurred.
Check the publication date. An EPD older than seven years should be viewed with caution unless the manufacturer explicitly confirms current production matches the assessed period. Manufacturing processes, energy grids, and supply chains change. Old EPDs may not represent current impacts.
Assess Methodology Transparency
Quality EPDs explain their methodology clearly. Poor EPDs hide behind vague statements and missing sections.
System Boundaries
The EPD should explicitly state which life cycle stages are included. At minimum, construction products should cover A1-A3 (product stage). Better EPDs include more stages.
Look for justification of exclusions. If an EPD omits certain processes, it should explain why. “Transport excluded due to variability” is reasonable. “Manufacturing impacts excluded” is not, unless the EPD is specifically for raw material extraction only.
Be suspicious of unusually narrow boundaries without explanation. An EPD that only covers raw material extraction and ignores processing, transport, and packaging is incomplete for most purposes.
Functional or Declared Unit
The EPD must clearly state what quantity it describes. For products with defined performance, a functional unit describes what the product does. For materials and components, a declared unit describes the physical quantity.
Examples of good functional units: “1 m² of wall insulation achieving thermal resistance R-value 3.0 m²K/W” Examples of good declared units: “1 kg of cement”, “1 m³ of ready-mixed concrete”
The unit should make sense for the product type and allow meaningful comparison. An insulation EPD using kilograms as the declared unit makes comparison difficult because insulation performance depends on volume and thermal properties, not mass.
Data Sources and Quality
This section separates quality EPDs from mediocre ones. The EPD should identify data sources for key processes.
Primary data: Measured data from the specific manufacturing facility. This includes energy consumption, material inputs, emissions, waste generation. Primary data comes from the manufacturer.
Secondary data: Generic data from databases or literature. This includes background processes like electricity generation, transport, raw material production.
Quality EPDs use primary data for processes the manufacturer controls. Ideally more than 50% of environmental impacts should come from primary data. Using secondary data for background processes is standard practice.
Red flag: An EPD using entirely generic data. This essentially describes an industry average rather than the actual product. While generic EPDs have their place, product-specific EPDs should reflect real manufacturing data.
The EPD should state data collection period and geographic scope. “Energy data from 2022 production year, average across three UK manufacturing sites” is good. “Energy data from literature” is weak.
Allocation Methods
When manufacturing produces multiple products simultaneously, impacts must be allocated between them. The EPD should explain the allocation method.
Common methods include mass, economic value, and physical relationships. None is inherently superior. The PCR often specifies which method to use. But the EPD must state what it actually did.
Missing allocation explanations suggest sloppy work or deliberate omission. This particularly matters for materials with significant co-products, like cement production.
Evaluate Data Coverage and Results
Beyond methodology, examine what the EPD actually reports.
Complete Impact Categories
Quality EPDs report multiple impact categories, not just carbon. EN 15804 requires at minimum:
Global warming potential (GWP) Ozone depletion potential (ODP) Acidification potential (AP) Eutrophication potential (EP) Photochemical ozone creation potential (POCP) Abiotic depletion potential for elements and fossil resources (ADP)
Better EPDs include additional categories like water use, particulate matter, toxicity indicators.
Reporting only GWP is insufficient for construction products following EN 15804. This indicates the EPD either predates current standards or doesn’t properly follow them.
Module Tables
Construction product EPDs should present results in module tables. These show impacts for each life cycle stage: A1 (raw material supply), A2 (transport to manufacturer), A3 (manufacturing), etc.
The tables should include all declared modules. If modules are marked “ND” (not declared) or “MND” (module not declared), check this is justified. Not declaring optional modules like end-of-life stages is acceptable. Not declaring mandatory modules like A1-A3 is not.
Technical Properties
EPDs are environmental declarations, but should include technical information supporting their scenarios and assumptions. This might include:
Density and physical properties Performance characteristics Lifespan assumptions Installation requirements Maintenance needs
Missing technical data makes it impossible to verify whether scenarios are reasonable. For example, if an EPD claims a 60-year lifespan but provides no technical justification, you cannot assess whether this assumption is credible.
Significant Figures and Units
Results should use appropriate precision. Reporting GWP as “3.456789 kg CO₂e” suggests false precision. LCA involves uncertainty. Three or four significant figures is typically appropriate.
Units should be correct and consistent. Mixing units without clear conversion factors creates confusion.
Red Flags: When to Reject an EPD
Some issues automatically disqualify an EPD from serious consideration.
No verification statement: Without verification, it’s not a valid Type III EPD. It might be an LCA report, but shouldn’t be called an EPD.
Unknown or dubious programme operator: If you cannot verify the programme operator exists and operates credibly, the EPD’s legitimacy is questionable.
Missing methodology section: EPDs must explain their approach. A document presenting only results without methodology is useless for quality assessment.
Overly narrow boundaries without justification: An EPD covering only a fraction of the product’s life cycle needs clear explanation why. Otherwise it appears designed to hide impacts.
Publication date older than 7-8 years: Production processes change. Old EPDs may not represent current manufacturing. Unless explicitly validated as current, treat them as historical documents.
Inappropriate functional unit: If the functional unit doesn’t match how the product is actually used or specified, the EPD has limited value. This particularly applies to comparison situations.
Generic data for critical processes: Using database values for your own manufacturing process suggests the manufacturer couldn’t or wouldn’t collect real data. This raises serious questions about data quality.
Unusually low impacts without explanation: If a product shows dramatically lower impacts than comparable products, this should be explained. Real improvements deserve documentation. Optimistic assumptions or calculation errors don’t.
No technical performance data: EPDs without technical properties cannot be properly evaluated. You need this information to assess whether scenarios and assumptions are reasonable.
Green Flags: Signs of Quality
Conversely, certain features indicate high-quality EPDs.
Recent publication (within 2-3 years): Fresh EPDs more likely reflect current production.
Comprehensive life cycle coverage: EPDs declaring all relevant modules (A1-D) provide complete pictures.
Detailed methodology explanation: Clear description of data sources, assumptions, and methods demonstrates rigour.
Primary data dominance: Using measured data for key processes shows commitment to accuracy.
Sensitivity analysis or uncertainty discussion: Acknowledging uncertainty and testing assumptions indicates intellectual honesty.
Technical documentation: Including performance data, test methods, and technical specifications shows thoroughness.
Regular updates: Manufacturers who update EPDs before expiry demonstrate ongoing commitment to transparency.
Geographic specificity: EPDs specifying regional data sources provide more relevant information than generic global averages.
Practical Quality Assessment Process
When evaluating an EPD, work through this sequence:
Quick check (2 minutes): Verify programme operator, check publication date, confirm verification statement exists. This eliminates obvious problems.
Standards review (5 minutes): Check ISO 14025 and EN 15804 compliance, verify PCR reference, confirm appropriate standards are cited.
Methodology review (10 minutes): Read the methodology section. Check system boundaries, functional unit, data sources. Look for transparency and completeness.
Results review (10 minutes): Examine module tables, verify complete impact categories, check technical properties are included.
Decision: Based on findings, classify the EPD as:
- Excellent: Comprehensive, transparent, recent, thoroughly documented
- Good: Meets requirements with minor gaps
- Questionable: Significant issues but might be usable with caveats
- Reject: Fundamental problems that invalidate the EPD
Document your assessment. If using the EPD for procurement or certification, record what you checked and why you accepted or rejected it.
Context Matters
EPD quality requirements depend on your purpose.
For LEED or BREEAM certification, you need EPDs meeting specific criteria. Review certification requirements alongside general quality assessment.
For product comparison, you need compatible EPDs following identical PCRs. Quality is necessary but not sufficient. Compatibility matters equally.
For general market intelligence or understanding typical impacts, even mediocre EPDs provide value. Perfect data is rare. Imperfect data beats no data if you understand its limitations.
For high-stakes procurement decisions or detailed building LCA, demand excellent EPDs. Poor data leads to poor decisions. Insist on quality or find different products.
Working with Suppliers
If a product lacks a quality EPD, you have options.
Ask the manufacturer when they plan to create one. Many manufacturers are developing EPDs in response to market demand. Expressing interest may accelerate their timeline.
Request specific improvements to existing EPDs. If an EPD is old, ask about updates. If methodology is unclear, request clarification. Manufacturers respond to customer requirements.
Consider alternative products. If a manufacturer won’t provide quality environmental data, competitors might. Your purchasing decisions signal what matters.
Accept limitations temporarily. If you need the product but the EPD is imperfect, use it while pushing for improvements. Document the EPD’s limitations in your assessment.
The Bigger Picture
EPD quality affects market transformation. Accepting low-quality EPDs perpetuates poor practice. Demanding quality drives improvement.
Manufacturers invest in better data when customers require it. Verifiers maintain higher standards when users scrutinise their work. Programme operators improve processes when weaknesses are identified.
Your role as EPD user includes quality control. By systematically assessing EPDs and making decisions based on quality, you push the entire system towards better outcomes.
This doesn’t mean becoming an LCA expert. It means applying consistent criteria, documenting decisions, and choosing quality over convenience when it matters.
Quality EPDs enable better decisions. Better decisions lead to lower-impact buildings. That’s the point of the entire exercise.
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