Data centres: building the invisible infrastructure that powers the world

What is a data centre and why does it matter?

In 2025, the volume of data created and consumed worldwide exceeded 180 zettabytes (one zettabyte equals one billion terabytes), and this figure is expected to triple between 2025 and 2029. This global digital explosion has placed data centres at the heart of today’s critical infrastructure. From the perspective of the construction sector, data centres represent one of the most technically specialised building types. It is not simply a matter of erecting a large warehouse filled with equipment: the structure, the building envelope, the electrical installations, the cooling systems and the security controls must all function with almost surgical precision. And increasingly, these buildings must do so in a sustainable manner.

Every time we send an email, check the weather forecast or ask artificial intelligence for help, that request travels to a building that almost no one ever sees. A data centre is not your typical company server at the end of a corridor; it is a highly complex industrial infrastructure, with thousands of servers and a multitude of auxiliary systems. They are designed to store, manage and process vast amounts of data and ensure it is always available, supporting essential digital services: from cloud platforms to artificial intelligence, including banking, public administration and the connected industry.

Types of data centres: they are not all the same

The construction of a data centre varies dramatically depending on its purpose and scale. Designing a facility for an SME is not the same as designing a massive node for a tech giant. A distinction must be made between different types of data centres based on various characteristics:

Classification according to purpose:

On-Premises, built and managed by the company itself for its exclusive use, offering maximum control
Colocation (Colocation),where the provider rents out space, power and security to various companies, enabling them to outsource their infrastructure
Cloud Data Centers, virtualised infrastructure hosted by cloud service providers (e.g. AWS, Azure), designed for scalability and on-demand use
Hybrid, which combine physical infrastructure with cloud services, optimising flexibility and security
Managed services, which are those where the provider not only rents out space, but also actively manages the customer’s infrastructure.

Clasification according to size and capacity:

Hyperscale, which are large-scale facilities designed for massive cloud computing and big data, operated by tech giants (Google, Meta, AWS)
Edge Data Centers, which are smaller, decentralised facilities located close to the end user to reduce latency
Micro Data Centers, which offer compact, often prefabricated solutions for specific requirements or confined spaces.

Classification based on their level of redundancy and guaranteed availability:

This classification is based on the Uptime Institute’s Tier standard, which is the global benchmark.

Clasification	Availability	Redundancy	Typical profile
Tier I	99.671%	No redundancy	SMEs, offices…
Tier II	99.741%	Partial	Medium-sized companies
Tier III	99.982%	Maintenance without downtime	Deployment, cloud region
Tier IV	99.995%	Total, fault-tolerant	Banking, defence, hyperscale

Energy consumption: some staggering figures

One of the most critical aspects of data centres is their high energy consumption. A hyperscale data centre can consume as much electricity as a city of 100,000 inhabitants. Designing them properly is not just a technical matter: it is a collective responsibility. The International Energy Agency (IEA) estimates the annual energy consumption of data centres at around 450 TWh, accounting for almost 2% of global energy consumption. And estimates suggest that this consumption could double by 2030.

The energy efficiency of a data centre is measured using the PUE (Power Usage Effectiveness) metric. A PUE of 1.0 is the theoretical ideal – all the energy goes to the servers – and a PUE of 2.0 means that for every watt of useful power, another watt is spent on cooling, lighting and other auxiliary systems. The industry average is around 1.5, although the best modern centres already achieve figures between 1.1 and 1.2.

PUE (Power Usage Effectivenes) = total energy consumption of the facility / energy consumption of IT equipment

Cooling can account for between 35% and 45% of a building’s total electricity consumption. For this reason, innovation in cooling systems – liquid immersion cooling, two-phase heat exchangers, indirect evaporative cooling systems – is one of the most active areas of research and also one of the fields where we at CARTIF see the greatest potential for technology transfer.

The waste heat from a data centre should not be wasted; it can (and should) be reused for district heating systems or for nearby industrial processes. A data centre can literally act as the boiler for an entire neighbourhood. Recent European projects demonstrate that it is feasible to feed this heat into district heating networks to heat homes and commercial buildings in winter, turning a problem into an energy asset.

Challenges and solutions in data centre construction

From a construction perspective, data centres differ significantly from conventional buildings. Their design is determined by three key factors: availability, security and efficiency. Unlike conventional construction, the building process for a data centre is governed by critical concurrence: civil engineering works and the integration of complex systems (electrical and mechanical) must proceed in perfect synchronisation. The greatest challenges facing this type of specialised construction are:

Structure and floor load: server racks can exceed 1,500 kg/m². Floor slabs must be dimensioned to a much higher standard than in a conventional office building, and the structure as a whole must incorporate robust construction solutions designed to withstand external risks (earthquakes, flooding, fire).
Redundant power supply: dual mains connections, diesel or hydrogen-powered generators, and large-scale UPS (uninterruptible power supply) systems are required to ensure there are no micro-outages. Electrical rooms may occupy up to 30% of the total floor area.
Cooling: this is the major challenge, as the amount of heat generated by the servers is enormous. Systems range from precision air conditioning (CRAC/CRAH) to direct liquid cooling at the rack level, chilled/heated ceilings and free-cooling towers, which utilise outside air.
Physical security: another critical aspect that must include biometric access control, 360° cameras, electromagnetic shielding (Faraday cages), early-warning fire detection systems using aerosol or clean agents that do not damage equipment, and building materials with high REI ratings.
Cable and infrastructure management: raised access floors and suspended ceilings must accommodate kilometres of fibre-optic cables and other wiring, with strict compartmentalisation and redundant routes.
Building envelope and efficiency: it is essential to incorporate highly insulated façades, roofs that minimise solar gain, and a carefully considered orientation to harness prevailing winds for passive free-cooling strategies. Finally, the layout of plant rooms, the building’s orientation, and the integration of passive and active systems must optimise overall energy consumption.

The construction process for a data centre has specific characteristics that set it apart from other types of building projects, primarily due to the need to precisely coordinate multiple disciplines that rarely come together in a single project: heavy-load structural engineering, medium-voltage electrical systems, precision air conditioning, advanced BIM management and monitoring technologies. Following an initial phase of highly detailed planning and design – often supported by BIM methodologies – the construction phase is characterised by a tightly controlled sequence in which civil works and the installation of critical systems proceed in parallel.

Construction usually begins with a robust foundation (foundations and structure) capable of withstanding heavy loads and ensuring stability against vibrations. Subsequently, particular importance is attached to the installation of redundant electrical systems (transformer stations, generator sets, UPS systems) and HVAC systems, the integration of which requires specific technical spaces and extremely precise execution. In the final stages, exhaustive testing (commissioning) is carried out to verify that all systems operate in a coordinated manner under different operational scenarios, which is critical prior to commissioning.

The life cycle of a data centre – from conception through to operation and decommissioning – offers fertile ground for the application of emerging technologies. The following are the most significant from the perspective of construction and facilities engineering:

Digital twins and BIM. The BIM (Building Information Modelling) methodology is now an absolute must for data centre projects. It enables the precise coordination of installations across all disciplines before construction begins, identifying clashes and sequencing the work. The next step is the operational digital twin: a model updated in real time using installed sensors, which enables the simulation of failure scenarios, the optimisation of load distribution, and the management of predictive maintenance.
Industrialised and modular construction. Prefabricated data centre modules help to improve quality and reduce commissioning times. This trend is being adopted by leading data centres as a strategy for rapid scaling.
Artificial intelligence in management and predictive maintenance. State-of-the-art DCIM (Data Centre Infrastructure Management) systems incorporate machine learning algorithms that optimise the operation of cooling equipment in real time, manage load distribution between servers and predict when a component is likely to fail before it does.
Direct Liquid Cooling (DLC). Given the power density of new artificial intelligence processors – which can exceed 400 W per chip – air cooling is simply not enough. DLC systems circulate water or a dielectric fluid directly to the processor via cold plates, shifting heat management to the hydraulic system and enabling that heat to be recovered at usable temperatures.
Renewable energy and hydrogen. Major technology corporations have committed to operating on 100% renewable energy, and many data centres are incorporating rooftop solar photovoltaic systems or using PPAs (Power Purchase Agreements). Green hydrogen is emerging as an alternative to diesel generators for long-duration energy storage, with the first pilot projects already underway in Northern Europe.

The economic impact of data centres: why regions are competing to attract them

The importance of this infrastructure to the economy is undeniable. In Spain, planned investment for this year exceeds €8 billion, with projections reaching €67 billion by the end of the decade. A large data centre is not just a building: it is a major economic catalyst. The construction of a hyperscale centre creates between 400 and 2,000 direct jobs during the construction phase, with high demand for specialist roles such as industrial electricians, HVAC technicians, fibre-optic network installers and BMS (Building Management Systems) operators.

Once up and running, data centres create stable, well-paid jobs – systems technicians, facilities engineers, security operators – and pay electricity bills that make a significant contribution to the revenue of distribution companies and to local tax revenues. Over the last three years, Spain has experienced a wave of investment, particularly in Madrid (which is already one of Europe’s five largest data hubs), but also in regions such as Aragon, Navarre and Galicia, which have set up one-stop shops and introduced favourable electricity tariffs to attract major operators who, in turn, draw in technology companies seeking proximity to the infrastructure. In regions such as Castile and León, with land availability, access to renewable energy and favourable climatic conditions, there is a clear opportunity to attract this type of investment.

From a regional policy perspective, investing in this type of infrastructure contributes directly to the objectives of the European Digital Agenda (Digital Compass 2030) and to technological sovereignty, ensuring that the data of European citizens and businesses is not stored exclusively on infrastructure in third countries.

Opportunities and benefits for businesses and researchers

As we have seen, data centres can offer significant benefits, including the creation of direct jobs during the construction and operational phases, the development of highly advanced energy and telecommunications infrastructure, the attraction of technology companies and start-ups, and, more generally, an increase in regional competitiveness.

The data centre sector opens up numerous business opportunities where collaboration between industry and research centres is particularly valuable:

Specialist technical consultancy. The market is in demand for architects and engineers with specific training in data centres. The shortage of professionals with this profile in Spain presents a real opportunity for firms and consultancies that invest in training and certification.

Research into energy efficiency. Technology centres such as Cartif play a key role in developing and transferring solutions for energy optimisation, waste heat recovery and integration with smart grids.

Advanced building materials and systems. The industry demands high-efficiency building envelopes, water management solutions for evaporative cooling systems, and materials with rigorous environmental certifications (EPD, cradle-to-cradle).

Predictive maintenance and inspection. The use of drones equipped with thermal imaging, inspection robots and AI-based data analysis platforms to predict failures in critical infrastructure is a growing market offering high added value.

Industrial symbiosis with waste heat. Integrating data centres into district heating networks requires systems engineering, planning permissions and innovative business models, which provide fertile ground for applied research.

CARTIF’s role in promoting sustainable data centres

Data centres are, paradoxically, the most influential buildings of our time and, at the same time, the most invisible to the general public. They are built in industrial estates, hidden behind unassuming façades, and only feature in the media when something goes wrong. Yet every internet search, every bank transaction, every video call and every query to an artificial intelligence model passes through them.

At CARTIF, we see these projects as an exciting crossroads: the need to build faster, more efficiently and more sustainably, whilst demand is growing at a rate that defies all forecasts. The decarbonisation of the sector, the smart management of water resources in regions such as Castile and León, and the integration of data centres into the urban and energy fabric of cities are challenges that require precisely the kind of applied research and public-private collaboration that is our raison d’être.