Managing the risk of the energy performance gap in non-domestic buildings

Abstract

Energy use in buildings accounts for one-third of the overall global energy consumption and total building floor area continues to increase each year as new developments are constructed and delivered. If stringent climate goals are to be met, these buildings will need to consume less energy and emit less carbon. However, design intentions for energy efficient buildings are not always met in practice. This performance gap between calculated and measured energy use in buildings threatens the progress necessary to meet these energy targets. The aim of this paper is to identify the factors that contribute to the performance gap and propose solutions for reducing the gap in practice. A quantitative and qualitative analysis of two research programmes completed in the past few years was utilized for an in-depth look at the performance of around 50 non-domestic buildings in the United Kingdom. While no direct links were found between any one variable and the performance gap, several correlations exist between contributing factors indicating a complex, entangled web of interrelated problems. The multitude of the variables involved presents a formidable challenge in finding practical solutions. However, the results indicate that the combination of the ventilation strategy of a building and the building services control strategy during partial occupancy is a key determinant of the performance gap. A more straightforward procurement approach with clearly delineated targets and responsibilities, along with advanced and seasonal commissioning instituted at the beginning of a project and implemented after building completion can also be very effective in reducing the gap. Finally, mandatory requirements or an appropriate system of incentives for monitoring and disclosure of performance data can help identify many of the underlying issues affecting performance in-use and untangle some of the web of complex issues across the building sector.

Practical application

Awareness of the performance gap and knowledge of the factors contributing to its impact on the building industry is important for all stakeholders involved in the design, construction, operation and occupation of non-domestic buildings. Understanding potential solutions to mitigate these risks may help to reduce the prevalence and magnitude of the performance gap.