Why the UK needs to be bolder on building performance — and how to fix it

As World Green Building Week calls on the construction industry to be "bold on buildings," the UK can take pride in its growing commitment to sustainable construction. The new UK Net Zero Carbon Building Standard is a great example of where we are leading the way. Yet behind the shiny heat pumps and gleaming solar panels lies an uncomfortable truth: new buildings often fall far short of their promised energy performance once occupied.

For decades, research has shown that UK non-domestic buildings typically consume more energy than predicted, and recent data suggests an average performance gap of 34%, which is a significant shortfall. With buildings using 30% of the UK's total energy and generating 19% of our carbon footprint, this waste places a hidden drain on our economy and undermines environmental goals. According to the Committee on Climate Change's 2025 progress report we're "significantly off track" on climate targets, including building decarbonisation - a sobering reminder that good intentions aren't enough.

The disconnect between design and reality

So why do buildings fail to deliver on their promises? This isn't about construction quality. The challenge lies in creating better feedback loops between design and operational phases to understand and improve performance. Often there’s limited opportunity for design teams to learn from post-occupancy data, while facilities managers inherit complex systems without sufficient resources or technical documentation needed to fully optimise building performance.

The simple truth is we can't manage what we don't measure. Monitoring the electrical and mechanical systems that deliver heating, lighting, cooling and hot water is essential to stop wasting energy, money and carbon. Yet even when we collect data, garnering insights and turning them into meaningful action remains a complex hurdle.

Regulatory pressure is mounting

The UK's regulatory landscape is finally catching up with the performance gap issue. The UK Net Zero Carbon Buildings Standard is in pilot phase, and alongside The London Plan's 'Be Seen' energy monitoring requirement, represents a watershed moment. Soon, developers and project teams will need to provide evidence of actual performance, not just theoretical models. Buildings that can't demonstrate real-world efficiency could face being stranded assets with reduced capital values.

Institutional investors are paying attention too, increasingly scrutinising operational performance through frameworks like the Task Force on Climate-Related Financial Disclosures. The message is clear: the market will no longer tolerate the gap between expectation and delivery.

Technology isn't the whole answer

The UK construction industry has embraced building technologies enthusiastically — smart meters, building management systems, IoT sensors. Yet technology alone hasn't solved the performance gap. Modern systems generate vast amounts of data, but buildings often have multiple standalone systems that don't communicate effectively. Most critically, there's a shortage of building performance experts who can bridge the gap between data and action.

What's needed isn't more technology, but a fundamental shift in how we think about buildings. We must stop viewing construction and operational costs as separate considerations. Building performance isn't fixed at handover, it evolves through active management and optimisation.

A practical path forward

In response to this challenge, Willmott Dixon developed Energy Synergy® - a performance management service that bridges the gap between design intent and operational reality. By combining real-time monitoring with expert analysis and continuous optimisation, the Energy Synergy® service helps improve efficiency, reduce energy use, lower carbon emissions, and cut operating costs.

To date, we've achieved 15% better-than-expected performance across 16 live projects. This demonstrates how we can go beyond monitoring to deliver active performance management of our customer’s buildings once in use.

The stakes couldn't be higher

Facing dual pressures of net zero targets and constrained budgets, we can no longer afford to ignore the performance gap. Every wasted kilowatt-hour represents unnecessary emissions and squandered resources. The buildings we're constructing today will operate for decades. Whether they fulfil their sustainable promise depends on the choices we make now - not just about what we build - but how we ensure optimal performance.

The future demands more than aspirations of sustainable development. It demands sustainable building performance. The question for the UK construction industry is simple: are we bold enough to bridge the gap between promise and delivery?

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Alasdair Donn leads the delivery of Willmott Dixon's Brilliant Buildings strategy, driving the company's sustainability targets and net zero commitments.

A recognised expert in building performance and renewable energy, Alasdair serves on multiple industry steering committees including CIBSE's Technical Memorandum TM51 revision for ground source heat pumps and the UKGBC's 'Advancing Net Zero' framework task group. He previously served as non-executive director of BSRIA (2017-2022) and was named Net Zero Hero of the Year at UKREiiF in 2021.