The proposed demolition of the remains of a 1,000-year-old Scottish castle to make way for a £5B data centre development has become the latest flash point in the UK's rapidly expanding digital infrastructure pipeline.

Hallyards Castle, near Auchtertool in Fife, sits within the site earmarked for ILI Group's 600-megawatt Cato data centre, one of a series of hyperscale schemes being proposed across Scotland.

Historic Environment Scotland declined to give the castle protected status following a request by local residents.

It said the planning process for the data centre was already underway and that it normally avoids intervening in planning or other regulatory processes by adding a new designation.

ILI submitted plans for Cato in June. The 62-acre scheme would involve around £5B of investment and be built in phases, with plans for as many as seven buildings and an on-site substation.

ILI Group insists that the remains will not simply disappear and said in a statement that it recognised “the importance of Hallyards to local people” and intends to ensure its history and heritage are recorded and reflected in the proposals.

Scotland has traditionally had a relatively small data centre market despite its access to renewable energy, but there are now gigawatts of proposed capacity across more than a dozen projects. However, the Scottish Parliament recently backed a de facto temporary moratorium on new hyperscale developments while new planning guidance is developed.

One of the biggest data centre proposals is the £16.5B, 1-gigawatt CX Technology Campus at Chapelcross, near Annan in Dumfries and Galloway. CX Tech has applied for planning permission in principle for eight buildings totalling more than 1.7M SF, alongside an on-site substation. Construction could run from 2027 to 2035.

The former nuclear site is being positioned as a brownfield location suited for large-scale digital infrastructure, with CX Tech proposing closed-loop, nonevaporative cooling, renewable power and the reuse of waste heat.

CX Tech Chief Executive Graeme Anderson said the project would bring together “scale, power, sustainability, resilience and the ability to grow over the long term.”

But the proposal has faced opposition, with South Scotland MSP Laura Moodie calling for the application to be rejected, arguing that the project could put pressure on energy supplies and the natural environment.

In Cheshire, renewable energy company Innova is consulting on a proposed data centre at Little Bollington on 148 acres of farmland within the Tatton Estate.

The Spodegreen project would form part of a circa 1.5M SF industrial and commercial campus following a reduction in the proposed development after local consultation. Digital industries, including data centres, have been mooted alongside a solar farm. A planning application is expected later this year or in early 2027.

Elsewhere, former energy infrastructure is being positioned as a potential solution to the industry's land and power requirements. At the former Fawley Power Station site near Southampton, Fawley Waterside is proposing a 1.5M SF industrial and commercial campus incorporating energy, digital, maritime, commercial and startup uses. Data centres and advanced computing are among the potential digital uses.

The proposal follows a consultation that reduced the planned floor space from more than 2M SF. Construction could begin by winter 2028.

Meanwhile, Amazon Web Services has secured planning approval for a data centre at Iver in Buckinghamshire, replacing industrial and warehouse units with a 330K SF facility. The project will include 27 backup generators, with most expected to use hydrotreated vegetable oil, while cooling will include outside air and rainwater where possible.

Buckinghamshire Council acknowledged potential landscape impacts but determined that the benefits, including the need for data centre capacity and employment opportunities, outweighed those costs.