Carbon data you can stand behind

Executive summary

Reliable carbon reporting needs an owner and a clear evidence trail for each important reported figure. Agree the framework, reporting period, activities covered and evidence needed before collecting data. Estimates can be legitimate when their basis and uncertainty are clear. Construction data passes between sites, purchasing systems, finance and supplier portals, so check those handovers. Begin with one figure that is important or prone to error. Better checks support customer review and assurance preparation, but do not guarantee an assurance conclusion. ^{[1, 2]}

In plain terms

Activity data describes what happened, such as litres of fuel used. An emission factor converts that activity into estimated greenhouse gas emissions. An audit trail records the quantities, units, period, factor, calculations, assumptions and checks so another person can follow the result back to its evidence.

Checks around the calculation

Blank and zero mean different things

On 31 July 2026 the government corrected its conversion-factor flat file because some unavailable values had appeared as zero. The full set was unaffected. Check the relevant file's correction notice and keep the exact version used. Missing, unavailable and not-applicable values must not silently become zero. ^[3]

Match data to the period, geography and technology required by the method. Materiality means significance under the reporting framework; use it to prioritise checks, while explaining exclusions. Check the coverage and quality of supplier figures too. ^{[1, 2]}

Recommended actions

A practical way to start, with suggested owners and timing:

1. 1.

   Define the evidence standard

   Keep the framework, period, boundary, materiality approach, owners and approval route; agree any external assurance scope early.

   Reporting sponsor, before collection

2. 2.

   Create the evidence register

   Give sources a reference, location, owner and due date; record coverage, units, factor versions, estimates and checks.

   Data lead, before the reporting cycle

3. 3.

   Check the inputs against other records

   Compare site and purchasing records with finance. Keep explanations for missing periods, duplicates and unusual changes.

   Finance and operations, each close

4. 4.

   Reproduce one complete figure

   Record the path from source evidence to the reported result. Resolve broken links and unclear assumptions. This internal review is not independent assurance.

   Reviewer who did not prepare the figure, before publication or submission

5. 5.

   Preserve the result

   Lock the approved pack, control access and retain it for the required period. Log later corrections and their effect on comparisons.

   Approver and data owner, at publication or submission

Example in practice

Worked audit trail: reconcile site diesel invoices and opening/closing tank records to litres consumed. Keep the factor and units, calculate emissions, and trace the figure through site and group totals to approval. Document allocations and missing data. Fuel delivered is not automatically fuel consumed in the period.

Common mistakes

• Dashboard used as the only evidence: keep source data and calculation steps.
• Published workbook overwritten: preserve the issued version and a correction log.
• Internal review described as assurance: name the work actually performed and its limitations.

How Reinventives can help

Our reporting process improvement can begin by checking the evidence for one important figure. You receive a documented audit trail, a gap list and a map of checks with named owners. We can then extend the approach across reporting. Formal audit, verification and independent assurance opinions are separate specialist services.

construction@reinventives.co.uk · 01908 023399

Sources and review dates

1. 1.GHG Protocol, Corporate Standard, revised edition, 2004; inventory quality and tracking over time.
2. 2.GHG Protocol, Corporate Value Chain (Scope 3) Standard, 2011; data quality and data management.
3. 3.DESNZ, Greenhouse gas reporting conversion factors 2026; correction notice, 31 July 2026.

Explaining changes: Separate changes caused by activity, operations, acquisitions or disposals, boundaries, methods, factors and data quality. A lower reported total does not by itself demonstrate an operational reduction. ^{[1, 2]}