Data Centre Construction in Ireland: Grid Limits and Steel Demand

Data centre construction in Ireland is still one of the largest single sources of structural and secondary steelwork demand on the island. How fast it goes from here depends more on grid capacity than on investor appetite. For fabricators north and south, the sector offers large, repeatable packages with demanding certification, programme and quality requirements. The businesses best placed to win that work are the ones getting ready before the next wave of connections opens up.

Data centre construction in Ireland has moved from boom to bottleneck

Ireland has one of Europe's densest data centre clusters, built up since the late 1990s and concentrated around the west of Dublin. A policy paper from the UCD Geary Institute for Public Policy counted 82 data centres operating in Ireland as of April 2024, with a further 14 under construction. The paper was written against the background of an EirGrid warning that data centre operators could leave Ireland if connection constraints continued.

That warning goes to the heart of the market. Planning, finance and client demand have all been available for Irish data centre projects. What has limited new starts is power. For a fabricator weighing up the sector, the realistic picture is a large, established market whose growth rate is now set by energy infrastructure rather than by appetite to build.

The evidence points to demand that is held back, not collapsing

Investor confidence in the Irish ecosystem has stayed strong through the slowdown. A KPMG review of 2024 deal activity recorded Blackstone's acquisition of a 50.7% stake in specialist engineering firm Winthrop Technologies for over €800 million, and Starwood Capital's €800 million investment in hyperscale developer Echelon Data Centres. The same review said Irish data centre activity had slowed temporarily because of energy infrastructure constraints. It also expected the European data centre industry to grow at a compound annual rate of over 20% over the next decade.

Signals from the wider supply chain point the same way. This week, electrical engineering group ABB posted record quarterly orders driven by data centre demand. Electrical plant orders do not tell us how much steel will be needed. They do show that hyperscale investment programmes are still running internationally, and those programmes will eventually need frames, platforms and plant supports.

Our reading is that the money and the clients are still there. For Irish fabricators, the real questions are where the next phase of data centre construction will be built and when, and whether their own businesses will be qualified to bid when it is.

Steel appears throughout a data centre build

A data centre is a steel-intensive building, though not always in the ways people expect. The primary frame over large data halls is often only part of the package. Much of the work for fabricators is in secondary and miscellaneous steelwork, which is extensive on these projects because of how densely they are serviced.

• Primary structure: portal and multi-storey frames over data halls, office blocks and plant buildings, with multi-storey layouts becoming more common where sites are tight.
• Plant support steel: roof plant platforms, generator and transformer supports, and frames for cooling equipment, often heavily loaded and built to tight tolerances.
• Services steel: pipe racks, cable management support steel and access gantries, coordinated with very congested mechanical and electrical services.
• Access and screening: stairs, ladders, handrails, walkways and framing for louvres and plant screens.

Many campuses are delivered in phases, one hall after another, so a fabricator that performs well on the first phase is in a strong position for repeat work on the same site.

Programme pressure shapes what main contractors ask for

Data centre clients want speed and certainty. Main contractors pass that pressure down the supply chain, and the result is a set of prequalification expectations that is usually tougher than on general commercial work.

Certification is checked from the start

Structural components must carry CE marking under EN 1090, and the fabricator's certificate has to cover the execution class the engineer has specified. On data centre projects that class is typically EXC2, although some elements may be set higher depending on the design. Welding quality management to ISO 3834 is frequently requested alongside it. A pattern we see across the membership is that tenders are lost at the prequalification stage over certification scope, well before price comes into it.

Management systems and carbon data are on the checklist

ISO 9001, ISO 45001 and ISO 14001 certification regularly appear on prequalification questionnaires for large campus projects. Site safety requirements on these projects are strict, and many hyperscale clients have published carbon commitments. As a result, fabricators are increasingly asked for embodied carbon information on the steel they supply. Requirements differ between clients, so read each tender carefully.

Digital coordination and offsite finishing

Dense services make clash-free 3D models a working requirement. Fabricators with in-house Tekla detailing capacity can respond faster to design changes and slot into the main contractor's BIM coordination process. Fire protection is increasingly applied offsite to keep site work to a minimum. That makes good control of intumescent coating application part of the fabricator's offer.

The risks are real and worth pricing in

• Timing risk: project start dates depend on grid connections, and they can slip. A business that turns away other work to keep a slot free for a data centre package can be left with an empty shop.
• Cash flow: large packages tie up working capital in material, labour and retention. Payment terms need the same scrutiny as the tonnage rate.
• Capacity strain: fast programmes squeeze welders, detailers and site crews. Overcommitting on one project can damage relationships with regular customers.
• Tier position: fabricators working several tiers down, under a mechanical or electrical contractor, can find their margin eroded by the time the package reaches them.

Opportunities reach beyond the hyperscale frame

The secondary and miscellaneous steelwork on data centre campuses is within reach of smaller certified fabricators that may not have the capacity for a full primary frame. These packages reward fabricators that respond quickly, check dimensions carefully and get certification right.

KPMG's review also noted that Irish firms with data centre experience are well placed for growing markets in Germany, Spain and Scandinavia. Irish main contractors and engineering firms are already working there. Fabricators that build a solid record with them at home have a credible route to following them abroad.

The grid constraint brings its own steelwork demand. Substations, energy infrastructure and grid reinforcement projects all use structural and secondary steel. They overlap with the wider pipeline covered in our analysis of Ireland's infrastructure backlog.

The outlook for data centre construction in Ireland depends on power

Some things are known. Ireland has an established cluster, international investment is still flowing into the Irish ecosystem, and power availability is what holds new construction back. What is not known is how quickly new grid capacity and connection policy for large energy users will develop. That will decide whether the next phase of building happens in the greater Dublin area, moves to other regions, or goes overseas.

The sector seems likely to provide a steady flow of expansion, refurbishment and phased work on existing campuses, though that is not guaranteed. A return to the build rates seen earlier this decade is far less certain. Fabricators should follow EirGrid, the Commission for Regulation of Utilities and gov.ie for the current status of connection policy, and plan without assuming that pipeline timing will hold.

Preparing for the next phase of data centre work

Since 2014, Irish Steel has supported fabricators as certification and quality requirements on large projects have tightened. For businesses looking at data centre work, the preparation is practical and can begin now:

• Check that the EN 1090 certificate covers the execution classes these projects call for, and that welding coordination is properly resourced through the Responsible Welding Coordinator course.
• Put together a ready-to-send prequalification pack with certificates, management system evidence, safety records and any available carbon data for the steel supplied.
• Build in-house detailing capacity, for example through the Tekla Advanced course, so the business can work to the pace of BIM coordination.
• Strengthen weld quality control with qualified people from the Welding Inspection course.

Main contractors on data centre programmes need certified fabricators they can rely on, and they need to find them quickly. Irish Steel members are listed on the Certified Register, which gives them visibility with the main contractors and customers who choose fabricators. Members also get fast-track technical and compliance support when a tender raises a certification question. Details of membership are available at irishsteel.ie/join.

Common questions about steelwork on Irish data centre projects

What execution class is usually needed for data centre steelwork?

The project engineer sets the execution class, and on data centre projects it is typically EXC2. Some elements may be set higher depending on the design. Before tendering, fabricators should check that their EN 1090 certificate covers the class specified. Irish Steel's EN 1090 guidance at /standards/en-1090 explains how certification scope works.

Can smaller fabricators win work on data centre projects?

Yes. Secondary and miscellaneous steelwork such as plant platforms, pipe racks, stairs, handrails and screen framing is often let as separate packages, and those suit smaller certified fabricators. Certification, accurate detailing and dependable delivery usually matter more than size for this work.

Why has data centre construction in Ireland slowed?

Energy infrastructure is the main constraint. KPMG's review of 2024 described a temporary slowdown in Irish data centre activity because of energy infrastructure constraints, and EirGrid has warned about the effect of connection limits. For the current status of connection policy, check EirGrid, the Commission for Regulation of Utilities and gov.ie.

What certifications do main contractors ask for on data centre tenders?

CE marking under EN 1090 for structural components is a legal requirement. Welding quality management to ISO 3834 and management system certification to ISO 9001, ISO 45001 and ISO 14001 often appear on prequalification questionnaires too. Requirements differ by client and main contractor, so check each tender's documents.

This article is for general information only. For guidance on standards, certification, or training, contact the Irish Steel team.