Energy performance of existing buildings and retrospective BIM application

The concept of BIM and its application have been around since the 1970s, and it has witnessed a surge in its application over the past decade. However, the existing literature is not sufficient in terms of clear guidelines in the form of a framework or roadmap that could specifically be used to inform the retrospective application of BIM particularly in the context of energy analysis on existing buildings. Consequently, there is a need for a mechanism for energy analysis of existing buildings that can holistically evaluate the relative energy performance of existing buildings and provide opportunities for information sharing and evidence-based decision-making. Given the escalating necessity of rendering existing buildings more energy-efficient, this paper presents an innovative framework that is more holistic. This framework enables the application of BIM in retrospect with simulator tools on existing building stock to facilitate energy analysis leading to the simulation of energy performance results. A case study approach is adopted in which Revit is used to develop the digital model of the existing building and imported into Sketchup to generate a building energy model format that is readable to Energy Plus to facilitate energy analysis leading to simulated results of energy performance. This is further validated by consulting construction project managers in the field for which a semi-structured interview was adopted. This simulated result can form the basis for informed decision-making regarding retrofitting the existing building stock, reducing the amount of energy consumption and corresponding carbon footprint. The outcome of the study demonstrates that BIM can effectively be applied retrospectively, rendering the energy analysis process more efficient. This research can be of great interest to the built environment practitioners such as building energy consultants, and facilities managers. Recommendations are also presented for further research which may lead to a paradigm shift from the conventional approach of building energy analysis to a BIM-enabled approach. The approach devised in this study can assist to support decision-making by facility management teams and alike regarding upgrading of energy systems of a given building to improve energy efficiency and corresponding carbon footprints reduction.