Data Centre Capacity
Data Centre London
London is Europe’s largest data centre market and one of the three largest in the world. It is also one of the most constrained. Vacancy is at record lows, power connections in established areas are years away for new applicants, and competition for available capacity is intense. Enterprise organisations that understand this market — and know who to speak to — access capacity. Those that don’t spend months running into dead ends. Armason operates in London’s data centre market every day. We know what is genuinely available and what isn’t.
The London Data Centre Market
London holds approximately 2.77 gigawatts of installed data centre capacity in 2026, projected to reach 5.16GW by 2031 at a 13.2 percent compound annual growth rate. It hosts 53 operators across 135 facilities, accounting for roughly 80 percent of total UK data centre capacity and representing Europe’s largest single market.
Demand has exceeded new supply for five consecutive years. Colocation take-up is forecast at 189MW in 2026, against new supply of approximately 180MW. Vacancy is projected below six percent by year end — a record low. The structural demand pressure comes from three converging forces: hyperscaler AI infrastructure programmes running into billions of pounds of committed UK investment, the rapid growth of neocloud providers requiring GPU-ready capacity at short notice, and sustained enterprise demand for hybrid and colocation deployments.
The constraint is not space. It is power. Grid connection timelines at primary substations in West London and Slough now extend beyond seven years. New applicants to those queues face a decade-long wait in the worst cases. This has pushed development eastward to Royal Docks and Newham, northward to Hertfordshire and Hemel Hempstead, and westward to Oxfordshire — all markets where power headroom exists and planning appetite is supported by the government’s Critical National Infrastructure designation.
London at a Glance
2.77GW
Installed capacity in 2026
<6%
Vacancy rate by end 2026
135
Active data centre facilities across London
7yr+
Grid connection timeline at constrained substations
Source: CBRE UK Data Centres Outlook 2026, Mordor Intelligence, Armason market intelligence.
London Data Centre Sub-Markets
Where capacity exists — and where it doesn't.
West London / Slough
The established heart of the London market and Europe’s largest single sub-market. Home to Equinix’s LD campus and the FX trading ecosystem. New power connections are effectively unavailable — primary substations are at capacity and queues extend to 2031 at the earliest. Brownfield redevelopment and expansion of existing licensed capacity are the only realistic near-term routes to new space here.
London Docklands
The historic interconnection core, anchored in Tower Hamlets and Newham. Carrier-dense environment critical for financial services and low-latency workloads. Ada Infrastructure’s 210MW Royal Docks campus has become the market’s bellwether project. East London is forecast to grow at 18.95 percent CAGR through 2031 as new power availability supports development that West London cannot accommodate.
Hertfordshire & M25 North
The fastest emerging sub-market in the London orbit. Equinix’s 85-acre Hertfordshire acquisition and Colt’s Hayes Digital Park expansion signal the direction of travel. Grid headroom is comparatively accessible, planning support is strengthening under the government’s AIGZ framework, and land costs are substantially lower than core London. For enterprise buyers whose workloads tolerate slightly higher latency, this sub-market offers the fastest route to new capacity.
Oxfordshire & Reading
Culham in Oxfordshire is designated as one of the government’s first AI Growth Zones, with streamlined planning and infrastructure support. Reading has established data centre presence with good connectivity to London. Both markets are increasingly relevant for AI training workloads and large-scale enterprise deployments where latency to London financial infrastructure is not a hard constraint.
Sourcing Data Centre Capacity in London
The London market is not opaque to everyone equally. Operators with live capacity know what they have. Armason maintains active relationships with operators across all London sub-markets and tracks real availability against the speculative positions that fill much of the public-facing pipeline narrative.
For enterprise buyers, the process is straightforward. We take a structured brief covering your power requirement, density needs, redundancy specification, geographic constraints, and timeline. We then work through our operator network to identify what genuinely matches — not a broadcast to the market, but a targeted engagement with the right parties.
Where London capacity on your exact timeline does not exist, we will tell you clearly and advise on the nearest credible alternative — whether that is an adjacent sub-market, a different operator structure, or a phased approach that meets your immediate needs while the primary deployment is progressed.
We work across all sectors — AI and HPC, enterprise compute, healthcare and regulated, and technology and SaaS. Minimum engagement is 1MW. All enquiries are handled confidentially.
What Armason Tracks
Live operator availability — what is genuinely on the market now, including capacity that is not publicly listed but accessible through direct operator relationships.
Grid and power positions — which sub-markets have accessible connection capacity, which are queued out, and where new energisation timelines are realistic on a one to three year horizon.
Operator build programmes — which operators are delivering new capacity, at what scale, and on what timeline — including pre-let opportunities before official availability is announced.
Pricing and commercial terms — current market rates for colocation, power, and managed services across London sub-markets, so your requirement is structured with realistic commercial expectations from the start.
Looking for data centre capacity in London?
Tell us what you need and we’ll give you a clear picture of what’s available, what the timeline looks like, and who can genuinely deliver it. No broker lists, no generic introductions.
Related
Data Centre Power & Land
Connecting operators with powered land and landowners with grid connections across the UK.
Grid & Power Intelligence
Weekly analysis of UK grid developments, power constraints, and new connection activity from the MI Roundup.