This week in UK data centres:
- BNEF’s 2026 Data Centre Outlook forecasts UK capacity nearly tripling by 2035 — but identifies that 53% of the planned UK pipeline is early-stage, held by first-time developers without planning permissions, raising a direct question about how much of the announced pipeline will actually convert to operational capacity
- Computer Weekly’s analysis of Barbour ABI data sets the committed UK pipeline at over 14GW, with the Cottam power station SMR campus — a 1GW proposal backed by Holtec, EDF and Tritax — the standout entry in the pre-planning list, despite a power timeline that points to 2030 at the earliest
- Construction Magazine’s assessment of the £100bn pipeline concludes that the next test is conversion rather than demand — with Wapseys Wood, Ampthill Road and Dartford all directed into the NSIP regime this year, and grid strategy, contractor appointments and MEP long-leads now the milestones that distinguish real construction workload from development proposals
BNEF: UK capacity set to triple — if the pipeline converts. 53% of it is early-stage.
Bloomberg NEF published its 2026 Data Centre Outlook this week. The headline is that UK data centre peak power demand is forecast to reach triple the installed capacity of 2025 by 2035, with the UK remaining Europe’s largest data centre market throughout that period. More than half of EMEA growth is concentrated in the UK, Germany, Spain, Finland and France. The underlying demand drivers — AI training, enterprise compute, sovereign cloud — are genuine and the BNEF base case treats them as persistent.
The caveat in the BNEF analysis is as significant as the forecast itself. Of the planned IT capacity in the UK pipeline, 53% is classed as early-stage: projects without development permits, run by developers who have no prior experience building a data centre. The UK’s pipeline is more concentrated into first-time developers than any other major EMEA market. BNEF flags this directly as a question about how much of the announced pipeline will make it from proposal to reality.
The structural implication is not new — it is the same one that the Burges Salmon report, Savills, and the Armason analysis have been making throughout 2026 — but the BNEF framing gives it a specific quantitative shape. A pipeline that is 53% early-stage and first-timer-led is not a pipeline with 53% uncertainty. It is a pipeline where a significant proportion of the capacity that appears in headline figures will never be built, because the developers behind it do not have the experience, the relationships, or the capital structure to move from planning application to operational facility.
For operators and investors tracking the UK supply picture, the BNEF analysis is a useful corrective to pipeline numbers taken at face value. The Authority Inc data makes the same point from the planning side: of 50 monitored London projects, 26 are approved and 10 show a completed build in planning documentation — but only one has independently verified construction activity, and none has verified operational status. Planning approval does not mean a data centre will be built and operational. Power connection, construction, and commissioning are tracked separately because approval does not guarantee any of them.
Sources: UK data centre capacity set to nearly triple — if it gets approved — Energy Live News / BNEF | UK Data Centre Planning and Capacity: What the Evidence Actually Shows in 2026 — Daily Excelsior / Authority Inc | UK parliamentary research briefing on data centres — House of Commons Library
The committed pipeline is 14GW. The Cottam SMR campus is the most ambitious — and the most instructive — entry on the pre-planning list.
Computer Weekly’s analysis of three Barbour ABI datasets tracking UK data centre planning applications — from March, June, and September 2026 — puts the committed pipeline at over 14GW. That figure covers projects that have entered the planning system, not merely been announced. The pipeline has grown faster in Scotland than anywhere else in the UK over the six-month period, consistent with the Lanarkshire AIGZ designation and the South Wales AIGZ pipeline documented in recent roundups.
The standout entry in the pre-planning list is the proposed 1GW campus at the former Cottam coal-fired power station in Nottinghamshire. In 2025, Holtec, EDF and developer Tritax signed a memorandum of understanding to build Holtec’s SMR-300 small modular reactors on the site to power new data centres — potentially the UK’s first SMR-powered campus. Holtec’s SMR-300 completed its Generic Design Assessment in March 2026 and the joint proposal to government followed in June. Small modular reactors compress the decade-plus build of a large nuclear plant to roughly three to five years of construction — but licensing and site works still point to first power around 2030 at the earliest, while the data centre is targeted to come online sooner.
The Cottam proposal illustrates the pattern that is now visible across a significant portion of the UK pipeline: the ambition of the proposal, the credibility of the partners, and the available land and power potential are all genuine — but the timeline between announcement and operational capacity is measured in years, not months. A 1GW campus powered by SMRs is not competing for 2026 or 2027 demand. It is a bet on where AI infrastructure requirements will be in the early 2030s. That is a rational bet — but it needs to be understood as such.
Sources: UK committed datacentre pipeline grows to more than 14GW — Computer Weekly / Barbour ABI | UK Data Centre Development: Power and Energy — Clarion Solicitors
The £100bn pipeline’s next test is conversion. Wapseys Wood, Ampthill Road, and Dartford have entered the NSIP regime.
Construction Magazine published an analysis this week of the UK data centre pipeline’s conversion challenge — the gap between announced and planned capacity and the schemes that are actually generating real construction workload. The headline figure from Barbour ABI and BNEF combined points to a £100bn pipeline. The next test is not demand — it is conversion: planning decisions, secured grid capacity, financing, contractor appointments, and long-lead MEP orders are the milestones that will show which schemes are becoming real construction workload and which remain development proposals.
The NSIP regime is doing increasing work in the large-project pipeline. During 2026, the Secretary of State directed three major proposed data centre campuses — Wapseys Wood in Buckinghamshire (up to three hyperscale buildings, approximately 300MW IT load, with an integrated energy centre), Ampthill Road in Bedford, and New Barn Road in Dartford — into the Nationally Significant Infrastructure planning regime under Section 35 of the Planning Act 2008. The Section 35 direction establishes the route through the Development Consent Order regime — it is not itself permission to begin construction. But it consolidates planning, highways, and compulsory acquisition into a single process and removes the local planning authority from the determination role.
LCM’s analysis of data centre power and supply-chain risk in London construction makes the same point from the contractor side. Grid strategy, energy procurement, high-voltage infrastructure, and technical assurance are increasingly being managed as core project-delivery issues rather than background utilities work. For the supply chain, tracking planning, grid, financing, and MEP milestones will be considerably more useful than treating the full £100bn figure as live workload — because only the schemes that are progressing through those gates simultaneously are on a path to generating real revenue.
The pattern visible across all three signals this week is the same one the market has been generating all year, from a different angle each time. The pipeline is real. The demand driving it is genuine. The constraint on conversion — power, planning, capital, construction capability — is structural and consistent. The projects that are converting are the ones where all four constraints have been addressed, in sequence, before capital was fully committed.
Sources: £100bn UK Data Centre Pipeline Faces Power Delivery Test — Construction Magazine | Wapseys Wood data centre NSIP direction — Planning Inspectorate | Data Centre Refurbishment Challenges in the UK — Bell Build Ltd (LinkedIn)
The week in one line: BNEF forecast UK capacity tripling by 2035 while flagging that 53% of the pipeline is early-stage first-timers without planning permissions; Computer Weekly’s Barbour ABI analysis put the committed pipeline at 14GW with Cottam’s SMR campus as the most ambitious pre-planning entry and the most instructive illustration of the announcement-to-delivery gap; and Construction Magazine identified the conversion milestones — grid, planning, financing, MEP long-leads — that separate real construction workload from the rest of the £100bn figure.
Armason tracks infrastructure signals across the UK and European data centre market. For site availability, grid intelligence, or pipeline advisory, visit armason.co.uk.
Related reading
· UK Data Centre Intelligence — Week Commencing 14 September 2026
· Why most UK data centre pipelines fail before they complete
· Data centre site selection in the UK: the new sequence in a power-first market
