State of the nation review: performance evaluation of new housing

State of the nation review: performance evaluation of new housing

By Rajat Gupta, Oxford Brookes University

The UK’s legal commitment to a net zero emissions target by 2050 has driven the need for new dwellings to be built with high standards of insulation with mechanical ventilation, high efficiency heating systems and renewables.

Building performance evaluation studies have shown that that low/zero energy dwellings often underperform as compared to the design specifications, due to discrepancy in building fabric thermal performance, performance of heating and ventilation systems, and resident behaviour. Past studies have demonstrated that in-use energy use can be up to three-five times more than design predictions. However, access to these studies, their findings, and most importantly the knowledge from it, is limited. Moreover national policy targets for carbon reduction cannot be met without understanding, quantifying and minimising this performance gap between design intent and reality.

The State of the nation study published by Professor Rajat Gupta and Matt Gregg at Oxford Brookes University has revealed for the first time, a national picture of the actual performance of new build homes. An online and interactive map on housing performance where 91 performance evaluation studies across the UK have taken place. Analysis of data on actual energy use, thermal performance, building fabric performance, environmental performance and feedback from occupants has provided insight into housing performance at scale.

This State of the nation study offers useful learnings for EnergRev. The study emphasises that future UK housing must include measuring and monitoring to quantify and minimise performance gap – aligning well with EnergyRev’s research on monitoring and control of cyber-physical systems.

Developers, constructors and design teams require upskilling and re-training to improve design, specification and workmanship – as also shown by skills theme of EnergyRev. Involving residents in building performance studies is vital to ensure energy systems are understood, operated and controlled as intended. Engagement with users is vital for scaling up smart local energy systems. What is clear is that both building performance evaluation studies of housing and study of smart local energy systems are socio-technical in character, requiring an interdisciplinary approach.