Summary
- Wansbeck Regeneration has filed an outline application for up to 356,500 sq m of data centre space at West Sleekburn.
- The proposal includes substations, power plant, emergency generators, drainage, landscaping, and ancillary power generation up to 49.9MW.
- The scheme sits close to the QTS Cambois campus, adding to Northumberland’s emerging AI and hyperscale infrastructure cluster.
Wansbeck Regeneration has filed an outline planning application for a large data centre facility at West Sleekburn in Northumberland, with up to 356,500 sq m of gross internal area and associated power, substation, drainage, landscaping, and engineering works.
The application, registered by Northumberland County Council under reference 26/02160/OUTES, seeks outline permission with all matters reserved except access. The site is land north-west of High Brocklands, Brock Lane, West Sleekburn.
The proposal covers data centre buildings, ancillary offices, substations, power plant, emergency generators, and ancillary power generation of up to 49.9MW. The council validated the application on 17 June 2026 and has listed the application as registered.
Another large scheme near Cambois
The West Sleekburn site sits close to one of the UK’s most closely watched data centre development zones. Nearby Cambois is already associated with QTS’s planned campus at the former Blyth Power Station site, where large-scale data centre buildings and power infrastructure are expected under a separate scheme.
Northumberland’s appeal is not just land. Large data centre campuses need grid infrastructure, transmission planning, water strategy, construction labour, road access, security arrangements, and local political support. Former industrial areas can provide scale and regeneration arguments, but they still have to pass the practical tests of power, buildability, and environmental management.
The West Sleekburn proposal is at outline stage, so the final form, phasing, layout, building design, and technical specification will depend on later reserved matters applications and planning conditions. Even at this stage, the application description shows the project’s infrastructure footprint: substations, power plant, emergency generation, drainage, site access, and large building platforms.
Supporting reporting on the application indicates that the proposal has evolved from an earlier four-building concept to a three-building campus with two onsite substations. The power pathway will be one of the central questions for planners, communities, and future customers, particularly if bridging generation is used before a full grid connection is available.
Power is written into the application
The application description includes ancillary power generation up to 49.9MW. That figure is familiar in UK infrastructure planning because larger generation schemes can trigger different consenting routes. For data centre developers, onsite generation is increasingly becoming part of the early viability case where grid connections are delayed, conditional, or difficult to secure.
Bridging generation can help unlock early phases, but it brings its own questions. Planners will want evidence on emissions, air quality, noise, fuel supply, operational hours, grid interaction, and the route to permanent connection. A temporary power strategy also has to show what prevents interim arrangements from becoming a long-running operating model.
Emergency generators add another layer of scrutiny. Data centres need standby power for resilience, but local impacts can include testing noise, exhaust emissions, fuel storage, and cumulative effects where several large campuses cluster together. In Northumberland, those cumulative effects may become more important if West Sleekburn and Cambois progress in parallel.
A concentration of large data centre loads can also strengthen the case for grid upgrades, specialist construction supply chains, training, and utility investment. The same concentration can expose weak points in connection timelines, substation delivery, utility corridors, road networks, water management, and local environmental capacity.
Planning policy has shifted, but not disappeared
The UK planning context for data centres has changed materially. Data centres have been designated as critical national infrastructure, and ministers have confirmed that large schemes can be directed into the Nationally Significant Infrastructure Projects regime where appropriate. Local planning authorities are also being pushed to take digital infrastructure more seriously.
That policy direction gives applicants a stronger national infrastructure case than was available when data centres were treated mainly as warehouse-like employment uses. It does not remove the need for evidence on landscape, noise, biodiversity, drainage, highways, carbon, energy strategy, construction impact, and operational mitigation.
West Sleekburn will test how far the UK’s data centre push travels outside the established London, Slough, and M4 corridor markets. Northumberland offers large sites, industrial legacy, and a regeneration narrative, but it also sits outside the country’s traditional colocation core. Customers, grid planners, fibre providers, and contractors will all influence whether the region becomes a live cluster or a map of ambitious applications.
The application now moves into consultation and technical review. The documents will determine whether West Sleekburn becomes a credible piece of Northumberland’s digital infrastructure build-out or remains another large number in the UK planning pipeline.
Announced floor area is the easiest part to understand and the least useful on its own. The delivery case will sit in the substations, generation strategy, grid connection, reserved matters, and conditions that follow. Northumberland’s data centre future is being written through power infrastructure before the first data hall is fitted out.
