Benchmarking the energy performance of the UK non-domestic building stock: a schools case study
30 November 2016
By Sung Min Hong
Professor Philip Steadman
Professor Dejan Mumovic
2011 to 2014
Display Energy Certificate (DEC) scheme was implemented in the UK to encourage higher levels of energy efficiency by raising awareness of the operational energy efficiency of public sector buildings. A review of the energy benchmarks that underpin the scheme revealed that they are no longer accurate, and raised questions that formed the basis of this research. The research therefore aimed to improve the understanding of how energy is used in non-domestic buildings, and to explore ways in which the energy performance non-domestic buildings could be evaluated through benchmarking with greater robustness.
The research comprised four phases of analyses within which data of varying granularity were analysed to acquire a holistic understanding of the patterns of energy use in English schools and the factors that influence it. Firstly, the latest DEC records of various public sector buildings were analysed. Secondly, the patterns of energy use in primary and secondary schools were analysed in greater detail. Thirdly, multiple regression analyses of a smaller number of schools were carried out. Lastly, detailed information of end-use consumptions and building services of a small number of modern secondary schools were analysed.
The main findings highlight shortcomings of the DEC scheme with regards to the classification system, energy benchmarks, and the adjustments. Analyses showed that there are two key issues associated with the classification system; inappropriate levels of aggregation and misclassification of buildings. Energy benchmarks were found to be out-of-date, therefore inappropriate for majority of benchmark categories. Various intrinsic building features were found to be correlated to the actual patterns of energy use, suggesting possibilities of raising the comparability of benchmarking. The research concludes that the DEC scheme lacks robustness, and that there are considerable potentials for improving the robustness of benchmarking the operational energy efficiency of non-domestic buildings.