ExCeL London: the hottest construction market in Europe, led out of Ireland

Data Centre World fills ExCeL because data centres are the most wanted construction market on the continent. I sat at a table with Mercury and listened to how the European leader actually delivers. The interesting part was who was leading.

Data Centre World fills the ExCeL in London every spring, and it fills it because data centres are, right now, the most wanted construction market on the continent. Not one of the most wanted. The most. Every developer, operator and contractor who touches the sector is in those halls for two days, and the reason is simple: the money is moving faster than the people who can build it.

The numbers behind the room are not modest. The European Commission puts the investment Europe needs in digital infrastructure by 2040 at over a trillion euros. The building does not slow down before 2030; it accelerates. Everyone at ExCeL knew it, and everyone was quietly asking the same question I have been asking on site for a year: who is going to build all of it.

A table with Mercury

The most valuable hour of the two days was at a table, not a stand. I sat with someone from Mercury Engineering, and I listened more than I talked. Mercury is the European leader in data centre construction, two billion euro in revenue last year, most of it data centres, with a target of three billion by 2029 and Germany already their strongest market. When a company that size explains how it actually delivers, you take notes.

What struck me was the honesty about the model. There are two ways to deliver: the agency model, where you take labour by the hour and manage it yourself, and the full package, where you hand a scope to someone who arrives with their own army, their own supervision, their own compliance, and gives you back a finished thing. Mercury does both, depending on the country, the client and the risk. The bigger and more repeatable the programme, the more it moves towards the package.

You can rent hands by the hour, or you can hand over a scope and get back a finished thing. The whole industry is a spectrum between those two.

That spectrum is my business. Today we sell hours: crews on data centre sites in Frankfurt and the Netherlands, employed locally, supervised, housed. The direction of travel, for us and for everyone serious, is towards the package, because that is where the margin and the trust are. Sitting at that table, I did not feel like a supplier. I felt like someone looking at his own next five years drawn on a bigger scale.

Led out of Ireland

Here is the part that outsiders miss. The hottest construction market in Europe is, to a remarkable degree, led out of Ireland. Dublin is the largest data centre hub in Europe, outpacing the old FLAP-D group of Frankfurt, London, Amsterdam and Paris. Ireland built the expertise first: the cool climate, the tax regime, the hyperscalers who came early, and IT Sligo running Europe's first degree in data centre engineering with Google. The country ran out of grid before it ran out of ambition, so the contractors who learned the trade in Dublin took it abroad.

Now the Irish names are the ones delivering the German, Dutch and Nordic programmes. Mercury targets three quarters of a billion in the Nordics alone by 2029. The men on those sites are increasingly not Irish and not local; they are eastern European, and a large share of them are Romanian. Irish know-how, Romanian hands, data centres from Frankfurt to Helsinki. That is the real supply chain of the AI boom, and almost nobody says it out loud.

Why I was there

I did not go to ExCeL to walk stands. I went because the people who decide where the next programmes land are in that building, and because I wanted to hear, from the leader, how the work is really structured. I came away with two things. One, the market is not slowing down, so the people problem gets worse before it gets better. Two, the companies that win the next decade will be the ones who can put trained, legally employed, well-housed crews on site anywhere in Europe within weeks, not the ones who quote the lowest hourly rate.

Romanians are the largest foreign workforce on Europe's construction sites, and nowhere more than on the data centres. I know these men. I started on site at 16. My job now is to make sure that when the leaders in that room need the hands to match their pipeline, the answer already has a name.

Irish expertise, Romanian hands, European data centres. That is the market. I intend to own our part of it.