An integrated simulation framework for reducing the building energy performance gap based on organizational information processing theory

Abstract

The phenomenon of significant deviation of buildings’ actual energy consumption from their designated performance in design has been observed worldwide, which is known as the energy performance gap (EPG). The EPG has become a major barrier to the achievement of low energy buildings. Previous studies revealed various factors that contribute to the EPG. The inappropriate handling of design information in building energy design was realized as a major cause. Nevertheless, there is a lack of systematic research into the EPG, especially from the project management perspective. The aim of this thesis is thus to develop an integrated building energy assessment framework for eliminating the EPG by introducing and applying the organizational information processing theory (OIPT). A PG- square model, i.e. information processing gap vs. energy performance gap, is proposed and verified. The PG-square model provides an analytical framework for supporting joint analysis of the information processing performance of the design stakeholder network and the predicted building energy performance. First of all, a critical literature review and meta-analysis was conducted on previous empirical studies to investigate the magnitude of, causal factors of, and general solutions for the EPG. Semi-structured interviews were then conducted with eighteen professionals carefully selected from six major stakeholder groups, i.e. developer, architect, electrical and mechanical (E&M) engineer, energy consultant, contractor, and facility manager, to help to reveal the general perspectives and practices of building energy design in the Hong Kong building industry. Secondly, three major elements to improve the information processing capability (IPC) of the design stakeholder network were examined: (1) the organizational structure, (2) the adoption of innovative information technology, and (3) the application of decision-making techniques. A series of computational experiments were conducted for analysing the influence of stakeholder network’s topological structure on its IPC. The simulation model integrates the agent-based modelling (ABM) simulation and the social network analysis (SNA) method. This study then examined state-of-the-art collaborative building energy design technologies (BE-CDTs) to identify their characteristics of facilitating the collaborative work of designers. The application of innovative virtual reality (VR) technology was also explored through prototyping, and an application procedure combing the Design with Intent (DwI) method and VR was proposed. Finally, an adaptive building energy assessment framework was developed, which establishes a practical procedure of adaptively combing various information processing strategies (e.g. information collection, uncertainty modelling, and information fusion) for eliminating the EPG. The framework was illustrated through a case study of a medium-sized low energy commercial building in Hong Kong. Finally, the framework was validated through a focus group meeting with five industry experts to verify its applicability and effectiveness in eliminating the EPG. The findings of this study first reveal that the EPG in a low energy building and the information processing performance of its design stakeholder network are closely related and widely reported in empirical studies. Design information would be missing, biased, or erroneous when it is transferred between stakeholders when stakeholders lack appropriate information processing strategies. There is thus insufficient information to tackle with uncertainties in building parameters, which is a direct contributor to the EPG. The research findings also highlight the significance of strategies in the three major aspects of improving the information processing capability of the design stakeholder network, i.e. organizational structural mechanisms, the adoption of information technologies, and the application of decision-making techniques, so as to make the best use of the design information to reduce the EPG. In terms of organizational structure, centralized network topologies were found to be more effective in transmitting information among the stakeholder network. Nevertheless, when stakeholder’s individual capability is restricted, decentralized networks can be more robust to information overload risks. The differences between network topologies were also found to be influenced by the percentage of stakeholders with specific design knowledge. The findings from the examination of collaborative building energy design tools suggest that the integration with building information modeling, web-based techniques, and other innovative technologies (e.g. virtual reality) could help designers improve their collaborative work to better realistic energy-saving design. Finally, when information is collected from different sources, the findings show that the adaptive adoption of different uncertainty modeling and information fusion techniques could make the best use of design information. This PhD study contributes to the research of the EPG by improving both theoretical understanding and industry practice. The research findings can help to improve the information processing capability of the design stakeholder network, and to assess the building energy performance in a more accurate and systematic manner. The EPG can thus be closed based on the optimal utilization of the design information.