ISO 14064-1: the standard behind a corporate greenhouse gas inventory

Preparing a corporate carbon inventory brings you to two references: the GHG Protocol Corporate Standard and ISO 14064-1. They are complementary rather than competing. The GHG Protocol is a methodological guide on how to calculate; ISO 14064-1 is a specification standard defining how the inventory is designed, managed and verified.

Categories instead of scopes

The 2018 revision of ISO 14064-1 dropped the “scope” terminology in favour of six categories. Category 1 is direct emissions and category 2 indirect emissions from imported energy; categories 3 to 6 break the GHG Protocol’s Scope 3 into a more structured split: transport, products used, use of products, and other sources.

This does not create incompatibility. Categories map onto scopes, and most companies keep a single inventory reportable under both structures. Knowing the terminology difference matters when a tender specification asks for an “inventory compliant with ISO 14064-1”.

Materiality and inclusion criteria

The most useful discipline ISO 14064-1 adds is requiring the criteria for including or excluding indirect emissions to be defined in writing in advance. Criteria such as magnitude, influence potential, data availability and stakeholder expectation are documented, and each category is assessed against them. Excluded lines are reported together with the reason.

That blocks arbitrary exclusion. “We had no data” is not a justification; “we had no data, the estimated contribution is under one per cent, collection is planned for next period” is. It is one of the first documents a verifier checks.

Verification under ISO 14064-3

The third part of the series governs independent verification. There are two assurance levels: reasonable and limited. Reasonable assurance means deeper examination, more sampling and higher cost; limited assurance rests on analytical review. Tender and reporting specifications usually state explicitly which level they require.

Verifiability is designed in before calculation. If your inventory lives in formulas buried in spreadsheets, the verifier has to trace each cell individually and the cost rises. A system where the path from source data to result is traceable shortens verification substantially.

How the corporate inventory relates to product LCA

The two calculations feed each other but do not substitute for one another. A corporate inventory measures the company’s total impact over a year; a product LCA measures the impact of one unit of product. Categories 4 and 5 of the corporate inventory draw on suppliers’ product footprints, while the company’s own product EPD draws on the corporate inventory’s installation data. Two cuts through the same data pool.