The EU Taxonomy is a classification system that defines technical criteria to determine which economic activities qualify as being environmentally sustainable — including operating data centers. These criteria guide reporting under the Corporate Sustainability Reporting Directive (CSRD) and determine whether companies qualify for “green” financing.

The current taxonomy assessment criteria are based on 106 practices (out of 163) defined in the European Code of Conduct (EUCoC) for Data Centres. The European Commission is looking to revise the technical criteria for financial sustainability reporting starting in 2027, with public consultation due to open in early 2026. This report summarizes the recommendations made by the Commission’s Platform on Sustainable Finance as part of its review of the criteria (see Advancing sustainable finance: technical criteria for new activities & first review of the Climate Delegated Act, Activity 8.1 Data processing, hosting and related activities, page 122).

Data center maturity model

The Commission proposes changing the taxonomy technical criteria from the current EUCoC best practices to the eight practice groupings (see Figure 1) detailed in the standard, Data centre facilities and infrastructures maturity model for energy management and environmental sustainability (CLC/TS 50600-5-1), hereafter referred to as the data center maturity model.

Figure 1 Number of practices for each operational category of data center maturity model

Although the data center maturity model inherits content from the EUCoC, it consolidates all EUCoC practices (163) into eight operational categories. Understanding the taxonomy changes proposed requires a practice-to-practice comparison between the 106 EUCoC practices currently used and the data center maturity model. Another change relates to the audit protocol: whereas an EUCoC audit yields a pass/fail result, the assessment of a data center facility using the data center maturity model provides a five-level rating from 1 to 5 (with 5 indicating the highest level of environmental performance) for up to eight categories.

The Commission’s recommendations for review propose that level 5 should be required (for relevant practices) for an operator to be considered environmentally sustainable — including eligibility for “green” financing. Operators will need to clarify which practices are included and assess the impact of achieving a level 5 rating.

The Commission proposes leaving the audit frequency unchanged, with implementation of practices to be verified by an independent third party and audited at least every three years.

(For additional information on the data center maturity model see Maturity model for sustainability downplays site-level resiliency.)

Added technical criteria

The Commission’s recommendations propose extending the taxonomy scope to include technical criteria in the following areas:

• Greenhouse gas (GHG) emissions management. To align with other economic activities in the taxonomy, the Commission proposes that the data center maturity model practice of using 100% renewable energy (market-based) could alternatively be met by keeping indirect GHG emissions below 45g CO2e/kWh by 2027 and 25g CO2e/kWh by 2030 — equivalent to level 5 performance of the data center maturity model level. Focusing only on indirect emissions could underestimate the full environmental impact of data centers that rely heavily on on-site power generation, such as engine generators. An additional requirement is that cooling systems must use refrigerants with a global warming potential below 150.
• Pollution prevention and control. Data center maturity model level 5 performance is proposed, meaning that data center cooling systems must use chlorine-free refrigerants. Also, halogen-free refrigerants must be used in any refrigeration systems installed and in operation after January 1, 2013.
• Sustainable use and protection of water and marine resources. Operators should implement relevant practices (not specified) from the data center maturity model at level 4 compliance. According to the Advancing sustainable finance document detailed earlier in this report, this would require a “water use and protection management plan” (page 126) addressing the mitigation of the potential impact(s) of any water withdrawals or discharges from the data center to a nearby water body (subject to clarification from the Commission). The data center maturity model refers to standard EN 50600-4-9 (Data centre facilities and infrastructures water usage effectiveness) and includes practices related to managing and monitoring water use from different sources, such as reducing the use of discharged water and the capturing of rainwater.
• Circular economy. Compliance with a new technical criterion (to be developed) covering circularity and the use of second-life hardware.

Relation to Energy Efficiency Directive

The Commission recommends that the taxonomy technical criteria, where possible, should refer to the EU’s Energy Efficiency Directive (EED), including the EED’s key performance indicators and calculation methodologies. The recommendation makes a direct reference to the EED rating scheme. As a future recommended development, the taxonomy should refer to EED Minimum Performance Standards (MPS).

(For additional information on the EED rating scheme and MPS see EED status update: implications for data centers).

Conclusion

If the Commission succeeds in aligning the technical taxonomy criteria more closely to the EED, it could simplify overall reporting and lower operator costs — while reducing the time and effort required from key staff. However, the Commission will need to invest considerable effort to make this alignment effective (as the two have been developed somewhat independently). For example, the data center maturity model and the EED have different thresholds for PUE; and the data center maturity model includes cooling efficiency ratio (CER) requirements, whereas the EED does not.

The proposal of a 5-level rating system is also confusing. The proposal seems to suggest that level 5 performance (in most cases) is required to pass the assessment and secure ”green” financing, while levels 1 to 4 performance represent a fail.

A key question is whether using the data center maturity model is the right approach. A representative from the Commission has stated that one goal of the revised taxonomy criteria is to simplify and improve usability. However, an auditor currently using the existing EUCoC criteria believes that switching to the maturity model could make audits more complex and costly for operators. Notably, introducing more complex criteria goes against the Commission’s omnibus initiative, which aims to simplify corporate sustainability disclosure directives. Data center owners and operators should analyze the proposed changes and voice their opinions as a part of the Commission’s upcoming consultation process. (Comments can be submitted via the EU Taxonomy stakeholder request mechanism.)

Note: The regulatory analysis provided in this report is the opinion of Uptime Intelligence. Data center operators should validate the interpretations with their legal staff and any relevant regulatory authorities.