Mass migration: Why the public sector’s IT estate needs a modern home

In this guest post, Rob Horne, client engagement manager at the Cabinet Office-backed colocation firm Crown Hosting Data Centres, sets out why it is high time the public sector revamped its approach to infrastructure hosting

The hub of data-driven activity in many public sector organisations is likely to be a single server room with costly but inadequate cooling, open doors, and only vestigial security.

Almost all (97%) public sector on-premises computing continues in such inefficient and unreliable facilities. The UK public sector has consistently underinvested in IT infrastructure – and now we see the consequences as digital plans are put on-hold in another round of belt-tightening.

Yet to embrace the digital future, the public sector can still modernise its IT infrastructure by moving out of outdated on-premise environments and into purpose-built, shared datacentre facilities.

Shifting away from legacy server rooms and towards more modern infrastructure can help reduce cost, improve resilience, and support sustainability goals.

Crown Hosting, a government-backed service, has supported this kind of transition in practice – helping departments consolidate ageing estates without the need for major capital investment.

It makes no sense to persist with small, costly and outdated server rooms when far more cost-effective, resilient, environmentally sustainable and secure alternatives are available.

The Department for Science, Innovation and Technology’s (DSIT) State of Digital Government Review 2025 surveying 120 public organisations has outlined the drag-effect on digitisation created by continued use of outdated infrastructure.

As the report points out, the UK was a leader in digital government with the NHS App, GOV.UK One Login and Universal Credit to its name. Now, however, “the digital foundations are creaking and services have not kept pace with other countries or the private sector”.

The report says 47% of central government and 45% of NHS services lack a “digital pathway” which means citizens use the phone or paper correspondence too frequently. Services are not joined up and are impeded by legacy assets and systems. Most public sector organisations lack comprehensive registers or quantification of the legacy risk they carry.

The DSIT report found a quarter of public sector organisations suffered critical outages in 2024, including 123 in NHS England alone.

Despite the government’s cloud-first policy, only 53% of central government organisations have more than 60% of their estate in the cloud. Local authorities and the NHS are less advanced.

Almost all (95%) of NHS Cambridge’s estate is on-premises, for example. What cloud migration has occurred there has been with “one of two leading cloud providers” creating operational risk, the report notes.

If public sector leaders stick with the current outdated on-premise estate, they are not making best use of public money. DSIT found cooling costs, for example, can be three times the cost of power because of outdated buildings and facilities.

There are significant gaps in cyber resilience and many smaller public sector organisations have no backup.

Underinvestment in technology increases long-term costs and total costs of ownership, the report recognises, with maintenance of legacy systems costing three or four times that of modern alternatives.

Unfortunately, experience shows change only occurs after adverse events such as disruptions and outages, or lack of power to support upgrades or greater use of AI.

When organisations double their power requirement for IT in a small server room, it also doubles their cooling requirement, which becomes unsustainable.

This has led some public sector organisations to rethink their infrastructure entirely. Case studies from Crown Hosting show that relocating a 20KW server room can reduce electricity usage by as much as 75%, depending on the estate.

In Crown Hosting environments, the cost of cooling is a fraction of what is required in old server rooms – 15p for every pound of IT spend, compared with £3 in a server room.

While not all modern facilities deliver the same level of efficiency, the broader benefits typically include renewable power, high-voltage grid connections, and emergency backup systems to maintain operations during grid disruptions.

Contracts on pay-as-you-use basis provide more flexibility than some of the more complex, long-term binding arrangements that public sector organisations fear.

The upgrade in security could hardly be starker. Compared with the doors-open approach in overheating server rooms, public sector organisations can avail themselves of facilities with a 24/7 presence to maintain security and availability.

With public finances currently under strain, but digital ambitions still in place, public sector organisations need to modernise their IT estates. By doing so they can achieve greater value per pound while meeting more rapidly advancing the digital ambitions of government and public service organisations.