Andrew Jones, Head of Digital Maintenance and Asset Management at NG Bailey, whose team has supported Wellington Place in Leeds across facilities services delivery and energy management throughout the estate’s growth and expansion, shares why NABERS matters and what it takes to achieve a top rating.

NABERS UK is rapidly becoming the benchmark for measuring the real-world energy performance of office buildings. Administered by CIBSE, it differs from traditional design-stage certifications by assessing how buildings actually perform in operation, using 12 months of verified energy data.

It is important to distinguish between the two NABERS UK ratings. Design for Performance assesses a building’s predicted energy performance at design stage, while NABERS UK Energy for Offices measures how it performs once occupied. The real value of NABERS lies in bringing these together, ensuring that design intent is translated into operational reality.

This matters because too often buildings perform well on paper but fall short in use. NABERS addresses this “performance gap” by focusing on real, measured outcomes, providing a far more transparent view of how buildings actually perform day-to-day.

There is also a strong commercial driver. Higher NABERS ratings can reduce operational energy costs and attract occupiers with increasingly stringent ESG requirements, strengthening asset value and reducing vacancy risk.

Developed by MEPC, the buildings were the first in the UK to complete the full NABERS journey, progressing from a Five-Star Design for Performance rating to a Five-Star NABERS Energy for Offices rating in operation. Through continued optimisation and performance management, the buildings have very recently achieved an outstanding 5.5 Star NABERS Energy for Offices rating.

From design intent to operational performance

A Five-Star Design for Performance rating sets a clear target, but it does not guarantee how a building will perform in use. Delivering a 5.5-star NABERS Energy rating depends on how effectively that design intent is operated and maintained after completion.

At Wellington Place, the buildings were designed to meet ambitious performance targets, including an all-electric, Net Zero-ready approach, a fabric-first strategy, and the integration of renewable energy such as solar PV.

Closing the gap in operation

Following practical completion, NG Bailey took on responsibility for facilities services and energy management, working to ensure that the buildings performed in line with their Five-Star design ambition.

This reflects a wider industry challenge: bridging the gap between how buildings are designed to perform and how they actually operate. Without the right data, systems and operational focus in place, that gap can quickly emerge.

At 11 & 12 Wellington Place, a comprehensive metering strategy and real-time energy management systems provide detailed visibility of energy use. Working from the original performance model, and in collaboration with the design team, this has enabled continuous optimisation in operation.

Through advanced BMS analytics, targeted interventions and close collaboration with on-site teams, energy intensity has been maintained at 60.78 kWh/m² (NIA).

This data-led approach transforms facilities management into an active driver of performance, rather than a reactive function.

Collaboration and continuity

Sustaining high NABERS performance depends on strong collaboration across stakeholders. While design teams set the intent, operational teams are responsible for delivering and maintaining it in practice.

A lack of continuity between construction and operation is often where performance begins to drift. Limited metering visibility, over-reliance on modelling assumptions and insufficient occupier engagement can all contribute to underperformance.

NABERS addresses this by requiring independent verification of performance in use, creating a continuous feedback loop that drives accountability and improvement.

Continuous optimisation as the baseline

A NABERS Energy rating is valid for 12 months, meaning performance must be continually maintained. At Wellington Place, this is achieved through ongoing facilities services, digital maintenance and data-led optimisation, ensuring that systems remain efficient as operational demands evolve.

A model for Net Zero performance

As the industry moves towards Net Zero, NABERS UK provides a credible, data-driven framework for demonstrating real operational energy performance.

The success of 11 & 12 Wellington Place shows that while design intent is critical, it is operational performance that ultimately defines success.

For facilities managers, the message is clear: high-performing buildings are not simply designed: they are actively managed, measured and continuously improved in use.