You have commissioned an EPD. Data has been collected. The LCA practitioner starts building the model and comes back with a list: this supplier figure covers different modules, that one was calculated under the previous version of the standard, this one has expired, and this one is a corporate footprint rather than a product level number.
The data was not wrong. It was misaligned, which for verification purposes is the same thing.
Collecting supplier product carbon footprint data for an EPD or an LCA is a different exercise from collecting it for Scope 3 reporting. For Scope 3, a reasonable figure with documented provenance is usually enough. For a verified declaration, the data has to satisfy a specific rulebook, and the rulebook decides, not you.
Here is how to get data that survives verification.
Start With The PCR, Not The Supplier
Every EPD is produced under a product category rule, and that PCR, at a specific version, defines the functional or declared unit, the modules you must declare, the allocation approach, the cut-off criteria, the data quality requirements and the characterisation factors.
Before a single supplier is contacted, establish:
- Which PCR applies to your product, and which version is currently active with your programme operator.
- Which standard version. Since July 2022, new construction product EPDs in the EU must follow EN 15804+A2. Older +A1 declarations remain valid until their stated expiry, but you cannot mix +A1 and +A2 data in one assessment, because the impact categories and characterisation factors differ. This is the single most common source of unusable supplier data.
- Which modules. Under +A2, the minimum scope for most construction products covers A1 to A3, C1 to C4 and module D, not cradle to gate alone.
- Whether a complementary PCR exists for your category, which usually becomes mandatory alongside the core one.
Everything downstream follows from these four answers. Get them wrong and you will collect a great deal of data you cannot use
Know What Must Be Primary And What Can Be Generic
This is where teams over-collect and under-collect at the same time.
Primary data is required for processes under your control. Your manufacturing energy consumption by type and site, production volumes, yields, scrap and rework, process emissions, waste, packaging, and transport distances where you know the actual supply chain. Module A3 is your responsibility and generic data will not substitute for it.
Generic or database data is acceptable for upstream processes, provided quality is adequate and documented. Most EPDs rely primarily on database values for supply chain inputs, and that is entirely legitimate under ISO 14025. Where supplier specific data genuinely improves the result, use it. Where it does not, a well chosen background dataset is often the better answer.
Data age rules apply. As a working rule under EN 15804+A2, primary process data should be less than five years old and background datasets less than ten, with justification required for exceptions. Your reference period should also represent a normal operating year rather than a commissioning run or an unusual one.
The practical consequence is that chasing every supplier for primary data is usually the wrong strategy. Identify the inputs that dominate your result, pursue those, and use documented generic data for the rest.
The Acceptance Test: Eight Checks Before You Use A Supplier Figure
When supplier sustainability data arrives, run it through these before it enters the model. Most rejections happen because one of these was skipped.
- PCR and version. Was it calculated under the same PCR, at a compatible version? Two EPDs are only comparable if they share the same PCR or fully aligned versions.
- Standard version. +A1 or +A2. Do not mix them.
- Declared unit. Per kilogram, per square metre, per item, and whether it matches how you consume the input.
- Modules covered. A1 to A3 only, or a fuller scope. You cannot infer the missing ones.
- Characterisation factor set. Programme operators specify which set applies, and versions change. A figure calculated on an older set is not interchangeable with a current one.
- Verification status. Third party verified, self declared, or unverified. Your verifier will ask.
- Validity date. Published EPDs are typically valid for five years. An expired declaration cannot support a new one.
- Cut-off and allocation approach. Whether the supplier applied rules compatible with your PCR.
Record all eight against every figure at the point of receipt. Doing it later, across two hundred inputs, is where projects lose weeks.
The Decision Tree When The Data Does Not Exist
Most suppliers will not have what you want. That is normal, and it does not stop the project. Work down this order:
1. A verified EPD for the specific product, under a compatible PCR and version. Best case, and increasingly common for major construction materials.
2. A supplier specific product carbon footprint, calculated to a recognised methodology such as the PACT Methodology or ISO 14067. Usable if the boundary, unit and factors align, though verification status will be noted.
3. A recognised background dataset from an established LCA database, selected for technological, geographical and temporal representativeness, with the choice documented.
4. A justified proxy. A similar material or process, with the reasoning and the uncertainty stated explicitly.
5. Exclusion, but only within the cut-off rules. EN 15804 permits excluding minor flows under strict conditions, in the order of 1% of total mass and 1% of total primary energy per unit process, with total exclusions capped at around 5% of impacts per module. Substances of very high concern under REACH cannot be excluded regardless of quantity. Check the exact thresholds in your PCR, because programme operators state them explicitly.
The cut-off rules are also your stopping condition. They tell you when a supplier is no longer worth chasing, which is a question sustainability teams often struggle to answer and end up chasing everything.
Where no declaration exists at all, as is common for building services equipment, a structured estimation approach such as TM65 provides a recognised route to a product level figure rather than leaving a gap.
What To Actually Ask Suppliers For
Frame the request around modules, not around “your carbon data”. For a typical construction or manufactured product you need, per input:
- Bill of materials at declared unit level, including additives, coatings and packaging. Packaging is routinely forgotten and is required within A3.
- The supplier’s EPD or PCF, if one exists, with the PCR, version, declared unit, modules and validity date stated.
- Inbound transport mode and distance, for A2. Real routes, not assumptions, where you know them.
- Material composition and origin, sufficient to select a representative dataset if no supplier figure exists.
- Reference period for whatever they supply.
Ask for the metadata alongside the number every time. A figure without its PCR, unit and validity date will have to be chased again later, and by then the supplier contact will have changed. Our guide to designing the supplier request covers the specification and response rate side in more detail.
Sequence And Timing
EPD projects fail on timing more often than on data quality.
- Published EPDs are typically valid for five years. Start renewal work six to nine months before expiry, not after.
- Material changes trigger updates. Programme rules generally require an earlier update where impacts worsen beyond a defined threshold, commonly around 10%. A change of supplier, formulation or manufacturing site can cross that line.
- Request supplier data before the LCA modelling starts, not alongside it. Data arriving mid-model is what causes rework.
- Batch your requests by material category, so the same question goes to comparable suppliers at once and responses can be compared.
If you are producing EPDs across a product range, build the supplier data once at material level and reuse it across declarations rather than restarting per product. That is where the cost per EPD falls sharply after the first one.
Why Verifiers Reject Data
Worth knowing in advance, because these are avoidable:
- Mixed standard versions in one assessment.
- Declared unit mismatch between supplier figure and your consumption.
- Expired declarations used as current inputs.
- Corporate footprints presented as product level emissions.
- Undocumented dataset selection, with no justification for representativeness.
- Missing packaging in the product stage.
- Exclusions above the cut-off thresholds, or exclusions that were never quantified.
- Data older than the age limits without written justification.
How Enistic Helps
We produce EPDs, life cycle assessments, TM65 assessments and product carbon footprints for manufacturers and construction product suppliers, and we run the upstream data collection that sits underneath them.
The practical difference is that our AI enabled platform is built and maintained in house, and it holds the PCR reference, standard version, declared unit, modules, verification status, validity date and source document against every supplier figure. That means the acceptance checks happen as data arrives rather than at modelling stage, which is where most EPD timelines slip. It also cuts the data collection burden by up to 80%.
- 5,000+ compliant reports delivered.
- 100% compliance record, with no failures.
- 11.7% audit rate, against an industry average of 33%.
- 98% client renewal rate.
Our carbon consultants and auditors are all in house, with a named consultant on your account who works alongside your technical and procurement teams rather than handing over a data template and a deadline. One simple monthly payment, unlimited expert support, no day rates appearing partway through.
Product level carbon emissions reporting is becoming a condition of being specified rather than a marketing asset. The manufacturers finding it manageable are the ones who built the supplier data layer once, properly, and now reuse it across every declaration they produce.
Book a demo and we will review your product range, identify which declarations you need first, and tell you exactly which supplier data will and will not survive verification.