Why retrofit is becoming critical to data centre growth strategies

Data centre demand is soaring. With AI, cloud and edge computing, IOT and digital transformation reshaping economies, the need for resilient, high-performance infrastructure has never been greater. Yet operators face a growing dilemma: new capacity simply cannot be built fast enough to match demand.

Construction lead times are increasing. Power capacity and availability challenges are intensifying. Planning approvals are slowing. In response, operators are rethinking their growth strategies and they are increasingly turning to an approach that, until recently, was seen as a stopgap: retrofit.

Retrofit is no longer an emergency solution or a compromise. It is becoming a core part of long-term estate strategies for operators determined to stay competitive.

In this article, I explore why retrofit is becoming a strategic priority for data centre operators. I’ll look at the forces driving this shift, the engineering and operational challenges retrofit presents, how to plan a successful project, and lessons we’ve learned from delivering complex retrofits in live environments.

The forces driving retrofit adoption

Several converging factors are fuelling the shift toward retrofit:

• Power scarcity: In many key locations, hyperscale projects are monopolising available grid capacity. New sites struggle to secure reliable, scalable power. Retrofitting existing sites with established connections allows operators to grow without relying on uncertain new grid infrastructure.

• Permitting and regulation: Building new facilities has become a more arduous process, often slowed by environmental, planning, and political challenges. Retrofitting avoids much of this complexity.

• Cost escalation: The rising price of construction materials, labour, and specialist equipment is making both brownfield and greenfield developments riskier.

• Asset life cycles: Many first-generation data centres are now approaching end-of-life stages for critical systems, creating a natural trigger for major upgrades.

• Sustainability and carbon reduction: Retrofitting significantly reduces embodied carbon emissions compared to new construction. Extending the lifespan of a sound existing building through retrofit is almost certainly a lower carbon pathway. This approach aligns with global sustainability goals and offers a more environmentally responsible strategy for data centre expansion.

For many operators, retrofitting existing assets is the fastest, most cost-effective way to add capacity, improve resilience, and meet customer expectations without waiting years for a new build. In fact, upgrading an existing data centre can cost up to 40% less than constructing a new facility, while delivering comparable benefits.

Understanding retrofit: More than a patch-up job

Successful retrofit projects are far more sophisticated than simple patch-and-repair exercises. They involve careful modernisation of live environments, often involving:

• Upgrading mechanical and electrical systems, including UPS, cooling, and fire protection.

• Replacing ageing plant and infrastructure to meet today's resilience and energy efficiency standards.

• Reconfiguring white space layouts to support greater rack densities and changing cooling needs.

At EMCOR UK, we have delivered retrofit projects that demonstrate what is possible. For example, we recently transformed an existing office space into a fully operational UPS Switch Room for a major customer. The project supported two diverse power feeds, designed to allow future expansion up to 600kKA for each feed. We’ve also  delivered an external modular facility housing associated battery strings, complete with cooling, fire and leak detection, and enhanced security systems. All work was completed while ensuring there was no disruption to ongoing operations.

One of the key lessons from this project was the importance of early design flexibility. We had to factor in future growth requirements from the outset, not just the immediate need.

The engineering and operational challenges

Retrofitting a live, operational data centre is not without its risks. Compared to a new build, the engineering challenges are often more complex and unforgiving.

If not properly managed, retrofit projects can risk temporary cooling outages, loss of redundancy including accidental downtime. Early-stage risk identification and mitigation planning is critical.

Some key best practices deliverables include:

• Detailed phased planning to avoid downtime.

• Temporary systems to maintain cooling and power during works.

• Constant stakeholder communication to keep all parties aligned.

• Thorough pre-construction surveys to understand constraints.

Our engineering-led approach has been instrumental in solving these challenges. For instance, when delivering bespoke chiller gantries for various data centres in London, Birmingham and Guildford, we designed, manufactured, and installed platforms to accommodate restricted space urban sites. By using off-site fabrication laser scanning and 3D modelling, we reduced on-site risks and completed installations ahead of deadlines, ensuring operational continuity.

We learned that working in constrained city locations requires even more precision at the design phase. Every milimeter matters.

Assurance is another key factor. In today's risk-averse market, operators expect partners to demonstrate a proven track record, robust processes, and a deep understanding of critical environments. Retrofit projects demand nothing less.

Strategic considerations for retrofit success

Planning is paramount. Operators must understand when retrofit makes sense – typically triggered by end-of-life equipment, resilience concerns, or the need to enhance capacity without moving location.

A successful retrofit strategy involves:

• Uptime-first planning: Building programmes around business continuity, with minimal disruption.

• Future-proof design: Ensuring that the project requisite not only solve today's problems but allows for future scaling and new technologies.

• Partner selection: Working with suppliers who offer self-delivery models and have experienced, long-serving teams. Consistency of people and processes can make the difference between a seamless upgrade and costly disruption.

The benefit of retrofitting can reduce project timelines by approximately 30%, primarily due to savings in site development and utility setup.

Our in-house engineering and commissioning teams have been a vital part of our customers' success in these type of projects. Having experienced people who understand both the technical and operational pressures of live data centres is a major asset.

Retrofit as a growth strategy

In today's data centre landscape, retrofit is not an afterthought — it is a strategic advantage. Operators who embrace retrofit can add capacity faster, manage costs more effectively, and reduce their exposure to planning and power risks.

Before considering any retrofit, my advice would be to start with a full lifecycle and risk assessment of the site. Understand your resilience thresholds. Audit your critical systems. Prioritise upgrades that strengthen redundancy before expanding capacity.

With the right planning, engineering expertise, and risk management, retrofitting existing assets allows operators to meet demand today and build resilience for tomorrow.

I fully believe that retrofit will play an increasingly critical role in shaping the future of the data centre industry. And I’m proud to be helping our customers turn today's challenges into tomorrow's opportunities.