Sustainability: From Compliance to Core Advantage

Data centres now sit at the intersection of rapid digital growth, constrained resources, geopolitics and increasing public scrutiny. Sustainability has become a practical test of whether an asset can secure investment, obtain permits, attract demanding tenants and operate reliably and with resilience over the long term.

At Deerns, sustainability is a design and innovation driver as well as an engineering and business performance issue. Regulation may trigger the conversation, but value is created when sustainability requirements are translated into decisions on site selection, power availability, connectivity, cooling solutions, water stewardship, (cyber) security, materials strategy, operability and maintenance options and overall resilience. The objective is a solution that meets environmental ambitions while aligning with capital expenditure (CapEx) and Total Cost of Ownership (TCO).

Compliance is the starting point, not the destination

Across Europe, data centre operators face a more demanding regulatory and reporting environment. The Energy Efficiency Directive (EED), EU Taxonomy and Corporate Sustainability Reporting Directive (CSRD) requirements are bringing energy, water, emissions and renewable resources into sharper focus. Investors and major occupiers are asking for clearer evidence of how assets perform and for their ESG credentials.

For colocation providers, this evidence is increasingly important when competing for hyperscale clients. Major cloud and technology companies have their own sustainability commitments, which extend beyond their direct operations to the data centres they occupy. Demonstrable performance on energy, water and emissions therefore helps providers show how their facilities support those commitments.

3 questions now define the conversation:

• How low can Power Usage Effectiveness (PUE) go, without compromising resilience or Water Usage Effectiveness (WUE)?
• How are water use, renewable energy and waste heat reuse addressed as mandatory KPI’s?
• How will energy and water usage, and issues of noise pollution, visual impact and other community concerns affect permitting and long-term social acceptance of these assets?

These questions matter most before the design is complete and construction starts. Early involvement allows sustainability objectives shape the decisions that determine cost and performance rather than becoming corrective measures bolted on later.

Sustainability that creates value: 3 horizons

Sustainability performance in data centres isn’t about meeting a target – it’s a trajectory. Companies embracing such practices can gain a competitive edge as the sector keeps evolving.

Deerns frames sustainability performance across 3 horizons, each raising the bar on what “good” looks like. This ensures that data centre assets stay attractive to investors and tenants as expectations, technology and regulation keep evolving.

Horizon 1: How can the asset secure permission to operate?

• Regulatory and reporting readiness: Assess EED indicators (PUE, WUE, ERF and REF), DC Code of Conduct and EU Taxonomy alignment.
• Permitting and community risk: Assess permitting requirements and social impacts, including acoustic due diligence before site selection.
• Asset baseline: Establish energy, water, emissions and resilience performance.
• Legacy asset resilience: Develop upgrade and decarbonisation roadmaps for existing assets.

Horizon 2: How can the asset operations be optimised?

• Energy and resource performance: Optimise energy, cooling, PUE and WUE, with a focus on resource efficiency.
• Renewable energy: Secure renewable electricity through direct Power Purchase Agreements (PPAs).
• Resource recovery: Establish frameworks for waste-heat recovery with local networks and utilities.
• AI-ready resilience: Integrate tailored cooling and infrastructure solutions for higher-density, AI-ready assets.
• Performance transparency: Establish governance, measurement and reporting frameworks to track performance and demonstrate progress.

Horizon 3: How can the asset create strategic advantage?

• Net-zero and water-positive ambition: Set long-term targets covering operational and embodied carbon, water and circularity.
• Spatial integration and social licence: Position data centres as critical infrastructure that creates local value and supports long-term permitting resilience.
• Market positioning: Target top-quartile sustainability performance to strengthen asset differentiation and potential access to green financing.
• Investment readiness: Maintain eligibility for ESG-focused investment across the asset lifecycle.

Engineering sustainability into performance, value and asset differentiation

Data centres are highly technical assets where small design changes carry major capital and operational consequences. Cooling is the clearest example: in traditional air-cooled facilities, cooling can account for around 35% of energy consumption, while AI workloads are driving higher rack densities and a growing need for liquid-cooling-ready infrastructure.

This is where Deerns’ combination of specialist data centre engineering and sustainability advisory is distinctive. Our teams connect corporate ESG objectives and decarbonisation plans with the detailed engineering decisions required to deliver them.

3 essential activities to inform decisions:

• Assessing sites for climate, energy, water, physical, and free cooling opportunities.
• Modelling PUE, Water Usage Effectiveness (WUE) and resource demand alongside capex and whole-life operating cost.
• Preparing assets for technologies such as direct-to-chip liquid cooling, heat recovery and alternative cooling sources, without sacrificing reliability or future flexibility.

The aim is pragmatic optimisation. A technically impressive solution has little value if it creates unacceptable operational risk, can’t be maintained, or requires capex that the business case can’t support. Sustainability works best when engineering performance, financial performance and operational resilience are considered together.

Using local resources intelligently

Some of the strongest opportunities come from the site itself. In a legacy data centre, Deerns assessed the adjacent dock water as a primary cooling medium. The solution required careful control of return water temperatures, filtration, and protection of the aquatic ecosystem. The sustainability benefit depended on resolving these engineering details correctly.

Deerns has also worked with seawater cooling in the Middle East and Curaçao, Aquifer Thermal Energy Storage (ATES) in the Netherlands, and waste heat reuse in Italy.

Each approach has its own constraints:

• Water-based cooling must respect extraction limits, water quality, biodiversity and return temperatures.
• ATES depends on suitable subsurface conditions and an energy strategy designed around the building’s actual load profile.
• Waste heat reuse depends on temperature levels, infrastructure and viable local demand for recovered heat.

The same principle applies to façades, acoustics and landscape integration to favour social impact. Data centres can face opposition because of their noise, resource consumption or visual presence. Addressing these issues during site feasibility and concept design reduces planning risk and builds a better relationship between the asset and its surroundings.

Performance that strengthens the asset

Deerns has been designing low-PUE facilities for many years; our first PUE 1.2 data centre dates back to 2007, and we have designed more than of 5GW of IT power, from 500kW to 200+MW per building. This track record matters. Clients need evidence that ambitious performance targets can coexist with uptime, deliverability and commercial discipline.

As expectations, technology and regulation evolve, sustainability performance will increasingly influence compliance and risk, measurable operating performance, and asset differentiation. Deerns brings strategic sustainability advice together with the engineering needed to make these outcomes real. By addressing compliance, technical performance and whole-life value from the outset, sustainability becomes more than a requirement to meet. It becomes part of the asset’s long-term performance and value.