From intent to evidence
Laurie McKelvie, Technical Delivery Lead at IES, outlines what the UK Sustainability Reporting Standards mean for building services.
With the upcoming introduction of the UK Sustainability Reporting Standards (UK SRS), environmental performance will no longer sit alongside financial reporting as a parallel exercise. It will be treated as a material business consideration that must be supported by robust, auditable evidence. While adoption of the UK SRS exposure drafts S1 (General) and S2 (Climate) will be voluntary at first, mandatory reporting for larger entities is on the horizon. The proposed ‘Climate First’ relief period, which allows organisations to focus initially on climate disclosures under S2, should not be viewed as a pause. Climate reporting will be the first area under scrutiny.
For those involved in building services, from designers and consultants to contractors, commissioning specialists and operators, this has significant implications. The built environment accounts for around 39% of global energy-related emissions, placing the performance of building services systems at the centre of how organisations manage climate risk, control emissions, and demonstrate long-term resilience. A central requirement under S2 will be an evidence-based climate transition plan, setting out how emissions will be reduced over time. For most organisations, the credibility of that plan will depend on what can realistically be delivered across their building portfolio. Given the complexity, energy intensity, and long operational life of buildings, building services performance – and the quality of data to evidence it – will increasingly determine whether sustainability disclosures stand up to scrutiny.
Moving beyond design intent
One of the industry’s longstanding challenges is the gap between design intent and in-use performance. Buildings are often designed to meet regulatory targets or planning requirements, but once handed over, there is often limited visibility of how systems perform in reality. In some cases, buildings can even consume two to five times more energy than their design intended. Under a reporting regime that prioritises transparency and verification, this gap becomes a reporting and financial risk. Organisations will be expected to explain not just what was designed, but how buildings are actually operating and how performance is being improved over time.
Implications across the building services lifecycle
This reinforces the need for a more connected, whole-life approach to building services delivery, where performance is considered from early design through to long-term operation. A defining feature of UK SRS is its emphasis on data quality. High-level estimates and static benchmarks are giving way to expectations around traceability, consistency, and auditability.
At the design stage, digital twins can be used to allow teams to test how different system strategies will perform under realistic conditions, accounting for unregulated loads, differing occupancy patterns, and changing climate scenarios. This technology enables early comparison of options, creating an accurate evidence base that supports both design decisions and future reporting. Rather than relying on guesswork, transition plans can be built on clear insight into what delivers the greatest energy, carbon, and resilience benefits – and at what cost. Importantly, models developed at this stage should be treated as long-term assets. A well-structured performance model can be carried forward and reused, rather than discarded once compliance is achieved, helping maintain continuity between intent and outcome.
During construction and commissioning, the focus shifts from prediction to verification.
Quick wins
Poorly installed systems, incomplete commissioning, or undocumented changes can quickly undermine design intent. Digital performance models can act as reference points, helping teams validate system behaviour, sense-check control strategies, and identify deviations before they become entrenched. Typical quick wins include optimising fabric performance, lighting, ventilation, and heating strategies, prioritising insulation and glazing upgrades, and integrating on-site renewables where appropriate.
In operation, building services continue to define outcomes. Control strategies, maintenance practices, and user behaviour all influence performance – often in ways that are difficult to diagnose using metered data alone. Linking performance models to live operational data through tools like IES Live enables teams to understand how systems behave in use, act quickly on issues, and demonstrate measurable progress against transition plans.
Modern data platforms like IES’s iSCAN technology can also help teams map existing data sources, identify gaps, and put processes in place to improve data capture and validation over time. Maintaining continuity from design through to operation helps ensure that systems perform as intended and that sustainability objectives are achieved.
Ensuring reported performance reflects collective intent across the project team is critical. Modelling and digital twin approaches provide the context needed to link energy and carbon outcomes back to physical systems, control strategies, and operational choices, underpinning climate commitments with robust, engineering-led evidence.
Raising the bar
While UK SRS introduces new pressures, it also presents a clear opportunity for the building services sector to move beyond compliance towards demonstrable action. By embedding performance modelling and ongoing evaluation across the building lifecycle, building services professionals can help organisations manage risk, avoid inefficient or mistimed interventions, and reduce long-term energy and operational costs.
As sustainability reporting becomes more rigorous, the value of building services expertise becomes increasingly clear. UK SRS is not just a reporting framework; it signals that how buildings are designed, serviced, and operated will play a defining role in both environmental credibility and long-term business resilience.
