The missing factor that explains underperformance in high-spec buildings

Even well-designed buildings don’t always perform as intended once in use. From new developments to existing portfolios, the missing link is often how building systems are controlled, and the impact can be significant in terms of costs, carbon and long-term value.

The UK real estate sector is investing heavily in net zero. New developments are being designed with high-efficiency systems, low-carbon technologies and strong sustainability credentials. At the same time, asset owners are under pressure to improve performance across existing portfolios.

In both cases, a similar issue keeps emerging. Buildings don’t always perform as expected once they’re in use. And more often than not, the reason isn’t the technology itself; it’s how that technology is controlled.

The performance gap starts early and persists

When we look at how high-spec buildings often perform in reality, the gap becomes clear. Energy use is higher than expected. Systems don’t behave in a coordinated way, and comfort levels vary more than they should.

What’s striking is that the causes are rarely complex. Common issues include;

• Heating and cooling running at the same time
• Ventilation not aligned with occupancy
• Equipment operating outside of required hours

While these seem like straightforward issues, their impact is significant. Industry guidance suggests that poorly optimised buildings can use 10–30% more energy than necessary. Whether in a new development or an existing estate, that quickly becomes significant both in terms of cost and net zero targets.

The capability is there, but not being fully used

Most buildings already have a building management system (BMS) in place. In principle, that should provide the control needed to manage heating, cooling, ventilation and other core systems effectively.

But the problem lies in how these systems are set up, used and maintained over time.

In new developments, systems may be installed correctly but not fully optimised once the building is occupied. In existing buildings, patterns evolve over time, so control setups become less aligned with how spaces are actually used. The result? Buildings with the right systems still underperform.

This can be rooted in a tendency to treat building controls as something that can be set once and left. In reality, buildings change, occupancy shifts and systems drift. Without ongoing attention, performance declines, often gradually, but consistently.

The buildings that perform well over time tend to be the ones where systems are actively managed and adjusted as part of normal operation.

Small changes, measurable impact

From our work at SSE Energy Solutions, we have found that addressing this doesn’t always require major capital investment. For example, in healthcare environments, relatively targeted changes to scheduling and coordination can reduce energy use by 10 to 20%, without affecting critical operations.

In education estates, the issues often tend to be more straightforward, including buildings running out of hours or systems, such as heating and ventilation, working against each other.

Addressing these can deliver 5 to 15% improvements, often with limited upfront cost.

Compared to more capital-intensive interventions such as plant replacement or fabric upgrades, the payback for improvements in building controls can be in months rather than years.

In one London office building, we saw a relatively modest investment in BMS improvements deliver a double-digit reduction in energy use, with a payback period of around a year – and six-figure savings p.a. thereafter.

The same principles apply in more complex environments, including manufacturing sites where continuous operation depends on reliable, well-coordinated building systems.

The portfolio challenge

The issues are compounded at portfolio level. Without clear visibility, it’s difficult to know:

• Which assets are underperforming
• Where energy is being lost
• Where to focus time and investment

A more consistent approach to building controls, combined with better performance data, allows asset owners to take a more structured view, identifying patterns, prioritising interventions and scaling improvements across portfolios.