Summary
- FLAP-D live capacity reached approximately 3.8GW in the first half of 2026, with another 1.4GW under construction.
- Vacancy remains close to historic lows, while powered-land costs in the primary markets have risen sharply.
- Large, latency-tolerant AI workloads are increasingly following power into the Nordics and other secondary European markets.
JLL says Europe’s five largest data centre markets have reached approximately 3.8GW of live capacity, although the next phase of growth is spreading farther from the established hubs as available power and suitable land become harder to secure.
Frankfurt, London, Amsterdam, Paris, and Dublin — collectively known as FLAP-D — delivered 194MW of new capacity during the first half of 2026. JLL forecasts about 453MW of deliveries across the full year, which would be almost three times the volume completed in 2020.
Paris led first-half additions with 72.5MW, followed by London at 49MW, Frankfurt at 45MW, Amsterdam at 16.3MW, and Dublin at 11.4MW. A further 1.4GW is under construction across the five markets, with another 2GW in the planned pipeline.
That pipeline is substantial, but headline capacity figures conceal widening differences between locations. Frankfurt retains 311MW under development and 687MW planned, yet connection lead times of at least 24 months are governing how quickly those projects can reach the market.
Ireland’s revised connection framework, which took effect on 31 March, is also changing where capital is directed. Requirements around proximate generation and renewable energy matching are encouraging developers to examine regional sites rather than assuming that additional capacity can be concentrated indefinitely around Greater Dublin.
Colocation vacancy across FLAP-D stood at 6.4% in the second quarter. Frankfurt was the tightest market at 3.1%, while London, Paris, and Dublin recorded modest increases in availability as small tranches of new space were delivered.
Contiguous high-density capacity remains difficult to obtain across the five markets. Occupiers are therefore committing to space earlier, with partial pre-letting increasingly replacing speculative construction as the standard route to development finance and customer certainty.
Power changes the development map
JLL’s figures indicate that the established hubs are not being displaced. Latency-sensitive workloads, interconnection requirements, existing cloud regions, and dense customer ecosystems continue to hold demand close to the primary cities.
The split emerges when proposed workloads reach the scale associated with AI training. Requirements of 100MW or more can tolerate greater distance from end users, making available power, grid delivery dates, and the ability to assemble large sites more important than proximity to an established carrier hotel.
Greenfield developments are expected to account for 39% of the European pipeline between 2026 and 2028, compared with 8% previously. Hyperscale greenfield sites in the pipeline are now an average of 175 kilometres from their associated hub city, up from 46 kilometres.
That distance is a physical measure of the constraint facing the market. Developers can preserve access to the commercial ecosystem of a major city while placing the largest power loads where grid capacity, land, and planning conditions are more workable.
The Nordics, Iberia, Milan, and other secondary locations are consequently attracting a larger share of investment. More than half of Europe’s expected AI-related growth is now forecast to land in Nordic and Tier 2 markets.
The shift also reflects cost. Prime powered land across FLAP-D has increased from €1.24m per megawatt in 2021 to €2.26m per megawatt, an 82% rise. Primary locations now command an average premium of 2.3 times over secondary markets and four times over tertiary locations.
Lower land prices alone cannot create a data centre market. Sites still require dependable grid capacity, fibre diversity, planning consent, equipment supply, and a route to phased construction. Cheap acreage without an energisation programme remains cheap acreage.
JLL’s data reinforces the pattern examined in recent DataCentral analysis: Europe’s core markets retain their commercial and network advantages, while their infrastructure limits push the largest new loads into a broader regional system.
The next European capacity cycle will therefore be distributed rather than detached. Frankfurt, London, Amsterdam, Paris, and Dublin will continue to absorb latency-sensitive and interconnected demand, while AI-scale campuses increasingly depend on locations able to provide land and power measured in hundreds of megawatts.
