# We buy steam from a neighbouring plant for a CBAM product. How is that heat counted?

Canonical: https://senseible.earth/answers/cbam-imported-heat-from-neighbouring-plant

Heat you import is added to your production process with the emissions of producing it. Use the supplier's actual fuel and boiler efficiency data where you can get it; without it, the monitoring rules give a fallback factor. Heat counts for every CBAM good, including steel and aluminium, unlike grid electricity.

## How it enters the calculation

Measurable heat flowing into the production process carries an emission factor: tonnes of CO2 per terajoule of heat. Multiply the heat consumed by that factor and add it to the process's attributed emissions, alongside your own fuel.

## What to ask the heat supplier

- The fuel burnt and its quantity for the period.
- Heat produced, so the factor per terajoule can be worked out.
- Whether the boiler also makes power, which needs a split between heat and electricity.

## If the supplier will not share data

Use the fallback in Annex III of Implementing Regulation 2023/1773 and record why. A verifier will accept a documented fallback more readily than an unexplained number.

## Keep the records

Steam invoices or meter readings by month, the supplier's factor and its basis, and how the heat was split if one meter serves more than one process.

## What Senseible does here

Senseible reads fuel, electricity and production documents into dated, fingerprinted installation records, the starting point for the actual emissions an EU importer asks for.

- [Emissions from purchased steam](https://senseible.earth/answers/how-to-calculate-emissions-from-purchased-steam)
- [CHP emissions split](https://senseible.earth/answers/chp-emissions-allocation-electricity-and-steam)
- [CBAM boundary with two units](https://senseible.earth/answers/cbam-installation-boundary-two-units)

Sources: [Implementing Regulation (EU) 2023/1773, monitoring rules](https://eur-lex.europa.eu/eli/reg_impl/2023/1773/oj/eng), [CBAM Regulation (EU) 2023/956, consolidated](https://eur-lex.europa.eu/eli/reg/2023/956/2025-10-20), [European Commission, CBAM legislation and guidance](https://taxation-customs.ec.europa.eu/carbon-border-adjustment-mechanism/cbam-legislation-and-guidance_en)

Last reviewed 2026-10-22.