Practical EPD guide

Why Environmental Product Declarations are so difficult to compare

An EPD is a standardized disclosure, not a product scorecard. Two declarations can both be verified and standards-compliant while still describing different functions, quantities, lifecycle stages and modelling assumptions.

Standardized does not mean interchangeable

Meaningful comparison requires equivalent product function and technical performance, compatible standards and Product Category Rules, an appropriate unit, matching lifecycle modules, aligned scenarios and sufficiently compatible source data and calculation methods.

Verification improves confidence in an EPD, but it does not make unlike products or declarations automatically comparable. A mathematical conversion to one kilogram can fix a unit mismatch while leaving a functional mismatch untouched.

EPD comparison checklist

  1. Define the function and required technical performance.
  2. Choose a justified reference quantity and study period.
  3. Confirm compatible standard editions, PCRs and programme rules.
  4. Align lifecycle modules and system boundaries.
  5. Review service life, transport, use and end-of-life scenarios.
  6. Check geography, technology, data age and background methods.
  7. Report assumptions, exclusions and uncertainty.
  8. Verify every value against the original EPD.