Strategies for minimizing building energy performance gaps between the design intend and the reality

Abstract

The disparity found between the predicted energy consumption in the design stage of buildings and the energy use during operation is known as energy performance gap. According to recent studies, the actual energy consumption can be twice to five times higher than predicted by the model. Building energy performance gap can have significant financial and environmental impact. This study aims to address this issue by interacting with professionals in the industry to identify the factors that contribute to the building energy performance gap, and to explore strategies that can help minimise the gap in major office buildings. Semi-structured interviews with 13 building energy professionals were conducted to gather and analyse the relevant design factors that contribute to the gap. Possible strategies of managing the factors were also identified through the semi-structured interviews. The interview responses were analysed qualitatively using Nvivo software, and as a result, 8 factors of energy performance gap were identified, as follows: (i) Inaccurate design parameters, (ii) Failure to account for uncertainties, (iii) Lack of accountability, (iv) Poor communication, (v) Lack of knowledge and experience, (vi) Inefficient and over-complicated design, (vii) Lack of post-construction testing, and (viii) Lack of feedback. Recommendations were drawn from the strategies identified from the study, and a framework on how to address the energy performance gap in the design process was proposed. The framework has three categories, namely strategies for better regulation and better accountability, strategies for project team for accurate energy models, better communication and lack of expertise, and suggestions for training to set training requirements for upskilling the industry workforce.