The integration of Building Information Modelling (BIM) and Life Cycle Assessment (LCA) for buildings in South Africa.

Abstract

Anthropogenic growth has catapulted the effects of global warming and the building sector is at the forefront of emissions, responsible for approximately 37% of carbon dioxide emissions into the atmosphere (UNEP, 2022). This research addresses the need for South Africa to reduce carbon dioxide emissions in the building sector and investigates the integration of Building Information Modeling (BIM) and Life Cycle Assessment (LCA) as a framework for achieving lower carbon emissions for buildings. It also explores the adaptation of the Green Star SA rating tool to effectively incorporate LCA criteria. The research objectives include: 1) evaluating the use of BIM and LCA as a decision-making tool for improving the environmental performance of office buildings, 2) examining the interoperability of BIM and LCA through case studies, 3) identifying potential hotspots in buildings where improvements can be made and developing an improvement analysis, 4) establishing criteria for a BIM-LCA framework for Green Star SA, and 5) identifying motivations and barriers to adopting BIM-LCA in South Africa. To achieve these objectives, One Click LCA and Revit Software were used to evaluate a BIM-LCA framework of two case studies. The first case study used an existing building typical of BIM models prevalent in South Africa, with a low Level of Development (LOD), whereby the only material modelled was concrete of varying strength. The second case study was theoretically structured with a high LOD, and all major building materials included. Integrated BIM-LCA models were developed for both case studies. The results showed a similar order of magnitude, with respect to the environmental burdens of lifecycle stages. The operational energy of both buildings had the most significant impact on the environment followed by the materials used. This is due to the concrete frame of both buildings and the dependency on non-renewable energy (i.e., coal) to generate electricity in South Africa. The findings indicate that the BIM-LCA framework provides valuable information by quantifying environmental contributions, helping with optimizing alternatives. A reduction of carbon emissions could be achieved for both case studies and a series of interventions were evaluated. The integration of LCA with BIM showed promising results even for the case study with a low LOD and it can enable designers to incorporate and quantify specific environmentally and socially responsible interventions. However, insufficient data can be a major barrier for implementation in South Africa and may affect the validity of results depending on the type of building and the data included. For the Green Star SA LCA criteria were developed and the award of 3 points for conducting an LCA with a BIM LOD of 300 is proposed. The acquisition of data will be improved if LCA criteria are incorporated into the Green Star SA rating tool, thereby providing motivation for material manufacturers and the building industry alike to release more specific LCA information. This research also suggests ways of improving the interoperability of BIM-LCA in the local context and expresses the importance of developing a local database for Environmental Product Declarations (EPDs) and the establishment of a BIM-LCA platform for knowledge sharing.