By Will Curtis, Head of Network Engineers Design and Deploy
Introduction
Over the past 10 years, Operational Technology (OT) infrastructure has evolved drastically. What began as isolated control systems in plant rooms and utility spaces has developed into a connected digital ecosystem that underpins modern building energy management, security systems, and occupant services.
In 2026, OT networks are no longer niche engineering environments. Today, they’re part of vital digital infrastructure.
This shift is driven by three primary forces: connectivity, complexity, and cyber risk.
OT Is No Longer Isolated
Traditionally, building management systems and industrial controls were deployed on isolated networks with minimal cybersecurity considerations. They were never designed to interface with broader corporate infrastructure.
That expectation no longer holds.
Today’s smart buildings incorporate dozens of networked systems including HVAC controls, lighting management, access control, energy monitoring, IoT sensors, digital signage, and AV platforms. Increasingly, these systems connect to enterprise networks, cloud platforms, and remote management software.
As a result, OT environments now face the same risks as traditional IT infrastructure, but with significantly greater operational consequences. If an email server fails, productivity drops. If a building control system fails, the physical environment stops functioning.
The Cybersecurity Gap
One of the biggest challenges for OT infrastructure today lies in the gap between legacy building systems and modern cybersecurity demands.
Many OT protocols, such as BACnet and Modbus, were created decades ago. They prioritised reliability and simplicity, not authentication, encryption, or zero-trust design. In many installations, these protocols still operate across flat networks with weak segmentation or monitoring.
This creates a significant attack surface.
With the rise of cybersecurity frameworks like IEC 62443 and increasing regulatory pressure from directives such as NIS2, organisations are being forced to reassess how they design and manage OT environments. Segmentation, secure remote access, and network visibility are now non-negotiable in modern OT deployments. Yet many existing systems are still based on legacy assumptions that no longer apply.
Engineering for Resilience
Resilience is another defining feature of OT infrastructure in 2026. Building systems must function around the clock. HVAC, lighting, and environmental controls cannot sustain extended outages.
This means OT networks now require the same level of redundancy expected in data centres or service provider networks — including:
- Redundant switching
- Resilient network paths
- Dual power supplies
- Regular failover testing
At the same time, visibility of OT networks has improved significantly. Modern monitoring platforms can interpret industrial protocols and detect abnormal building system traffic.
This shift towards observability enables operators to identify issues sooner and address them before they impact operations.
The Road Ahead
OT infrastructure will continue to evolve rapidly. Buildings are increasingly data-driven. Artificial intelligence is influencing operations through predictive maintenance and energy optimisation. Edge computing is bringing processing power closer to building systems.
Digital twins allow teams to visualise infrastructure in real time. But even with these advancements, the fundamentals remain the same.
Reliable networks and clear architectural discipline form the backbone of resilient OT environments.
The challenge for engineers and operators is ensuring the supporting infrastructure evolves at the same pace as the systems that rely on it. Because in the connected world of 2026, OT networks aren’t just in the background – they’re the platform modern buildings run on.
Author:
Will Curtis, Head of Network Engineers Design and Deploy
Trust Systems.
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