UK Data Centre Pipeline: What Is Actually Built, Approved or Still Proposed?

Executive summary

This article analyses the projects recorded in our own UK data centre tracker as at 18 September 2026. Of 28 individual data centre projects published in the register, 9 are recorded as operational, 13 as approved, 5 as proposed and 1 as refused. No published record is currently classified as under construction or withdrawn. Five AI Growth Zones are held separately and are not counted as projects. Only three of the 28 records carry a disclosed capacity figure, which is the single most important limitation on any attempt to total UK capacity or future electricity demand from this evidence.

This is a snapshot of our tracked sample, not a UK census. A zero in a category means no project in our register is recorded that way; it does not establish that none exists nationally.

Why this matters to the UK

Almost every public claim about British data centre growth rests on a count of projects or a sum of megawatts. Both are only as good as the underlying record. The questions that decide whether a pipeline is real — has it started on site, does it have a grid connection, when will it draw power — are rarely answered in the announcement that generates the headline. Building the register slowly, from planning documents and regulatory records, is the only way we know to keep those questions visible.

The status snapshot

Data checked 18 September 2026. Five AI Growth Zones (Culham, North East / Stargate UK, North Wales, South Wales and Lanarkshire) are recorded separately as designated zones, not as individual facilities, to avoid double-counting a zone with the projects inside it.

Why approval does not mean delivery

A planning permission establishes one thing only: that a local planning authority, or an appeal body, has accepted the principle and detail of the development on that site. It does not establish that construction will begin, that the developer holds a grid connection capable of serving the site, that finance is in place, or when — or whether — the building will open. Those are separate processes, each with its own evidence trail, and permission can lapse unimplemented.

The grid connection point matters most for energy analysis. A permitted data centre without a firm, dated connection is not a dated electricity load. Connection queue positions are themselves now under review — see our analysis of Ofgem's proposed data centre connection reforms.

What capacity figures actually exist

Of the 28 individual projects in the register, exactly three carry a disclosed and defined capacity figure, and all three are stated as IT load:

• VIRTUS LONDON1, Enfield — 4.3 MW IT load, operational
• Manor Farm and land north of Wraysbury Reservoir — 72 MW IT load, approved
• Cambois data centre campus — 720 MW IT load, approved

No published record in the register carries a disclosed grid connection capacity or a stated whole-site electricity demand. The remaining 25 projects have no usable capacity figure at all: either nothing has been disclosed, or a figure exists in public reporting without a definition stating what it measures. Those records are held as unknown. They are not treated as zero, and they are not filled with an estimate.

This is why we publish no total UK capacity figure from the tracker. Adding 4.3 MW of measured operational IT load to 792 MW of approved-but-unbuilt IT capacity would combine an existing load with a permission, and would silently treat 25 unknowns as nothing. Any figure produced that way would be wrong in a direction that flatters the data.

Documented examples across the delivery stages

Skelton Grange illustrates the distinction the register is built around. A resolution to grant permission was announced in April 2026, and it was widely reported as approval. Until the decision notice is issued, the record stays at proposed. Cambois shows the opposite case: a large, defined IT load, approved through a documented committee decision — and still an approval, not a building.

What would change a status

Each move needs a dated, checkable document: a decision notice for approved; site evidence or a commencement notification for under construction; an operator or regulatory confirmation of service for operational; a refusal or appeal decision for refused; a withdrawal on the planning register for withdrawn. Press coverage on its own moves nothing.

What this evidence cannot tell you

• Total UK capacity. The register is a verified sample, not a complete list of UK facilities.
• Future electricity consumption. Even the three disclosed figures are IT load, not whole-facility demand or measured consumption. Our data centre electricity calculator shows how much the answer moves with utilisation and efficiency assumptions.
• How much of this is AI. Most records give no evidence about workload. We do not label a facility as an AI data centre without it.
• Delivery timing. Few records carry a verified operational date.

The register changes as documents are published. Treat the figures above as dated to 18 September 2026 and check the tracker for the current position, or the data centre growth section of the Index for capacity indicators and their evidence status. For what the capacity numbers themselves mean, see why data centre megawatt announcements can mislead.

Sources

Every figure above is drawn from the published records of the AI Energy Intelligence UK data centre tracker, each of which carries its own primary source and verification date. The individual sources used in the examples table are linked in that table. Our verification rules are set out in the research methodology.