Colt starts construction on 54MW Berlin data center campus

Colt Data Centre Services (Colt DCS) has broken ground on a data center campus in Berlin with 54MW of total IT capacity, on a 9.5-acre site 10 km east of the German capital. The first of the two halls, Berlin 1, is due to go live by the end of 2028.

The plan predates the shovel. Colt announced Berlin 1 and Berlin 2 in April 2025, and roughly 15 months later H&MV Engineering confirmed the start of construction in a LinkedIn post this week.

"We're proud to celebrate the groundbreaking of Colt Data Centre Services' new development in Berlin, marking an exciting milestone in the delivery of critical infrastructure for one of Europe's leading data center companies," H&MV Engineering said.

What is being built?

• 9.5-acre site, 10 km east of the German capital
• 54MW of total IT capacity across Berlin 1 and Berlin 2
• Berlin 1 go-live target: end of 2028
• Electrical scope: a 110 kV G.I.S. substation (gas-insulated switchgear), delivered by H&MV Engineering
• Both halls announced April 2025

IT capacity is the load the halls actually serve; the site's grid demand runs well above it, because every megawatt of compute needs cooling, power conversion and redundancy wrapped around it. The 110 kV figure is the voltage at which power enters the campus.

Why the substation carries the schedule

H&MV Engineering, the contractor on the project, is delivering the 110 kV G.I.S. substation. That is the high-voltage switching and protection gear which takes grid power and steps it down to the voltages a data hall runs on, inside a compact enclosed footprint.

For a 54MW campus, the substation is the point where the utility network and the site's own distribution meet. It is also the class of equipment with long manufacturing and approval lead times, which makes it a sensible place to read a project's schedule risk — and it is the one deliverable Colt has named so far.

What changes for Colt's German footprint?

Today Colt operates three data centers in Germany, and all three sit in Frankfurt. Two further sites around Frankfurt are already under development, so Berlin is the company's first new build in a second German metro since it left that market.

The departure was deliberate. Colt previously ran legacy facilities in Berlin and Hamburg, and sold them to AtlasEdge in 2021 as part of a larger European portfolio disposal. Berlin is therefore a return rather than a first entry, and the location — a 9.5-acre plot east of the city — points to greenfield land rather than a conversion of an existing shell.

What does this change for capacity buyers?

Nothing lands before late 2028. Berlin 1 is nearly three years out, and Colt has published no date for Berlin 2. Anyone needing German capacity in the next procurement cycle still looks at Frankfurt, where Colt has three operating sites and two more in the pipeline.

What the groundbreaking does settle is the construction sequence. A contractor on site with a high-voltage substation in hand moves a project from announcement to delivery, and Colt says it has nearly 800MW of capacity under development across the UK, Europe and APAC (Asia-Pacific).

The company behind the build

• Founded 1992, originally City Of London Telecom
• Acquired by Fidelity Investments in August 2015
• 15 operational data centers
• Around a dozen further sites under development across the UK, Europe and APAC
• Nearly 800MW of capacity under development

Colt's Berlin program is staged rather than finished: 54MW announced across two halls, one phase dated, the other undated. The Frankfurt cluster stays the company's German center of gravity until Berlin 1 actually energises.