The EU Data Centre Rating Scheme and CSRD: Turning PUE and WUE Labels into ESRS E1 and E3 Evidence

What was adopted

On 21 September 2026 the Commission adopted a Delegated Regulation establishing a mandatory EU-wide sustainability rating scheme for data centres (per the Linklaters October 2026 ESG newsletter). Key features:

• An A-to-G label for facilities with 500 kW or more of installed IT power demand.
• Grading based on Power Usage Effectiveness (PUE) and Water Usage Effectiveness (WUE).
• Additional indicators: energy sourcing, new energy capacity, grid flexibility and waste-heat reuse.
• A two-month scrutiny period before entry into force, first labels expected in 2027, and a scheme review by end-2028.

It is not an ESRS metric

This is the point to get right. The rating is a product-level label under separate EU law. ESRS disclosures are entity-level and follow the double materiality assessment. A good PUE does not discharge an ESRS E1 energy disclosure, and an A label is not a CSRD claim. What the scheme does is create a well-defined, facility-level evidence set that overlaps with what you already have to report.

Where the overlap is

ESRS E1 (climate change). Energy consumption and energy mix are core E1 datapoints. The data used to compute PUE and the energy sourcing indicator will be metered facility data you can reconcile against your E1 energy totals and your Scope 2 inputs.

ESRS E3 (water). If water is material for your data centre portfolio, WUE inputs give you facility-level water consumption you can reconcile to your E3 figures.

Transition plan and targets. Grid flexibility, new energy capacity and waste-heat reuse are the kind of levers that belong in a credible climate transition plan narrative.

For operators

• Map each in-scope facility (500 kW and above) to the entity and reporting boundary used in your sustainability statement.
• Use one metering and data-quality process for both, so the label and the ESRS numbers cannot diverge.
• Document estimation methods; assurance providers will test the same source data twice.
• Remember the revised ESRS apply to financial years beginning on or after 1 January 2027, which lines up with when the first labels are expected.

For corporate customers

Companies that buy colocation or cloud capacity can use the label as supplier evidence for Scope 3 purchased services. Two cautions: the label does not give you your share of emissions, and under the new value chain cap you can only request data from suppliers with up to 1,000 employees through the standard channels, so a public label is a useful alternative to bespoke questionnaires.

What to do now

1. Identify which facilities, yours or your suppliers', will fall in scope.
2. Compare your current PUE and WUE inputs with your E1 and E3 data lineage.
3. Watch the two-month scrutiny period for changes before the rules enter into force.
4. Keep labels out of your sustainability statement claims unless they are clearly labelled as a separate scheme result.

Sources: Linklaters, ESG newsletter October 2026.