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London has 1.38GW of live data center capacity, with 278MW under construction and 1.5GW committed, according to a Cushman & Wakefield report
In sum – what to know
Growth remains strong – London has 1.38GW of live data center capacity, with 278MW under construction and 1.5GW committed.
Demand stays tight – Colocation absorption matched 117MW of new capacity over the past year, while 89% of capacity under construction is already preleased.
Constraints intensify – Power, grid capacity and planning constraints are increasingly shaping future development across the London market.
London remains EMEA’s largest data center market, with operational capacity reaching 1.38GW in the second quarter of 2026. Operational capacity increased 14% year on year, while pipeline capacity grew 13%.
The market had 278MW under construction, 1.5GW of committed capacity and a further 3.57GW at an early stage, according to the Cushman & Wakefield’s EMEA Data Center Update H1 2026. The report attributes the growth to sustained demand from hyperscalers, AI infrastructure providers, and colocation customers, while identifying power constraints as the principal barrier to delivery.
Wholesale colocation dominates London, accounting for 977MW, or 71% of live capacity. VIRTUS is the largest operator, with 185MW across 11 facilities, followed by Equinix, Ark Data Centres, Digital Realty, and NTT Global Data Centers.
Market fundamentals remain strong. Cushman & Wakefield said 117MW of new colocation capacity was added over the past year, alongside 117MW of absorption, meaning demand accounted for 95% of new supply. The key indicators show colocation vacancy at 5.58%, with 71.95MW of vacant capacity.
The level of preleasing also points to continued demand for capacity already being developed. The report says 89% of capacity under construction is already preleased, compared with 30% of planned capacity, reflecting greater uncertainty around longer-term projects and delivery timelines.
Hyperscalers are using a mix of self-build, wholesale, and build-to-suit capacity. Microsoft does not currently operate any self-built data centers in London, while CoreWeave has expanded through deployments in Crawley and London Docklands, delivered with Digital Realty and Global Switch respectively.
Nscale’s planned Loughton AI data center is expected to provide 50MW initially, with potential to scale to 90MW and become operational in the fourth quarter of 2026. Cushman & Wakefield said these projects reinforce London’s position as an important European location for high-density AI infrastructure.
The distribution of capacity is also evolving. Slough remains London’s largest established cluster, with 422MW of live capacity, followed by Hayes at 216MW, and the London CBD at 175MW.
At the same time, larger development opportunities are increasingly being explored in East, North and West London, where more substantial sites may be available. Many of these projects remain at an early stage and depend on securing sufficient power, planning approval, and grid infrastructure.
Power and planning remain the main constraints on future delivery. Grid capacity is heavily stretched, particularly in West London, while planning restrictions and competing land uses are making site assembly increasingly difficult.
Large projects have also attracted greater political scrutiny over electricity and water consumption, environmental impact and the use of Green Belt or protected industrial land. Proposed developments around Iver and the Lee Valley illustrate this tension, with local debate focusing on project scale, visual impact and whether data centers deliver sufficient employment and community benefits relative to their infrastructure requirements.
Opportunities in North and East London are typically linked to industrial land, brownfield redevelopment and access to grid infrastructure. Cushman & Wakefield expects London to continue attracting major investment, but says future growth will increasingly depend on securing power, establishing credible grid-connection timelines, demonstrating local benefits, and aligning projects with planning policy, all of which are becoming more difficult to achieve.
EMEA data center market enters a more constrained growth phase
Cushman & Wakefield’s broader H1 2026 EMEA update says capacity in the region’s traditional data center hubs is increasingly constrained even as demand for compute continues to climb. Established markets remain critical and continue to attract development, underpinned by deep cloud ecosystems, connectivity, and enterprise demand, while investment is accelerating fastest in selected Southern European and Scandinavian markets where power can be delivered more quickly and large sites are available at scale.
The report says that while demand has typically been a principal constraint to market growth, capacity is now being deployed wherever power, land, and viable delivery timelines permit. Across EMEA, operational data center capacity exceeded 12.1GW in H1 2026, up more than 36% in two years, while the total committed development pipeline reached 18.3GW, comprising 3.8GW under construction and 14.5GW planned. If fully delivered, that pipeline would more than double the region’s existing operational base.
