Integrated BIM-Based LCA for the Entire Building Process Using an Existing Structure for Cost Estimation in the Swiss Context

The building sector has a significant potential to reduce the material resource demand needed for construction and therefore, greenhouse gas (GHG) emissions. Digitalization can help to make use of this potential and improve sustainability throughout the entire building's life cycle. One way to address this potential is through the integration of Life Cycle Assessment (LCA) into the building process by employing Building Information Modeling (BIM). BIM can reduce the effort needed to carry out an LCA, and therefore, facilitate the integration into the building process. A review of current industry practice and scientific literature shows that companies are lacking the incentive to apply LCA. If applied, there are two main approaches. Either the LCA is performed in a simplified way at the beginning of the building process using imprecise techniques, or it is done at the very end when all the needed information is available, but it is too late for decision-making. One reason for this is the lack of methods, workflows and tools to implement BIM-LCA integration over the whole building development. Therefore, the main objective of this study is to develop an integrated BIM-LCA method for the entire building process by relating it to an established workflow. To avoid an additional effort for practitioners, an existing structure for cost estimation in the Swiss context is used. The established method is implemented in a tool and used in a case study in Switzerland to test the approach. The results of this study show that LCA can be performed continuously in each building phase over the entire building process using existing Building Information Modeling (BIM) techniques for cost estimation. The main benefit of this approach is that it simplifies the application of LCA in the building process and therefore gives incentives for companies to apply it. Moreover, the re-work caused by the need for re-entering data and the usage of many different software tools that characterize most of the current LCA practices is minimized. Furthermore, decision-making, both at the element and building levels, is supported.