BIM-based environmental impact assessment for infrastructure design projects

Sustainability is becoming a key factor in the decision-making process of infrastructure projects throughout their lifecycles. In particular, the Environmental Impact Assessment (EIA) in the design phase is becoming a matter of significant importance, for both public and private sectors, given the long-term impacts of design decisions on the environmental performance of infrastructure projects. Traditionally, EIA is performed by a sustainability expert at the end of the design cycle, by which time the modification of design is both costly and time-consuming. In recent years, Building Information Modelling (BIM) is leveraged to better integrate EIA with the design practices. However, there are several limitations with how this integration is approached: (1) EIA is normally performed by software other than the one used for the design. This renders the continuous EIA based on incomplete BIM models difficult; (2) there is a lack of explicit data structure for the integration of EIA and BIM data. This limits the interoperability and flexibility of the EIA tools in terms of accommodating to different EIA databases; (3) in the majority of the cases the integration of EIA and BIM is not bidirectional, which results in the incapacity of the designers to immediately visualize the results of EIA in the design platform and to track the progress of the design in terms of EIA; and (4) the BIM-based EIA has rarely been implemented in an infrastructure project. Therefore, this research aims to develop a continuous BIM-based EIA for infrastructure projects that utilizes an explicit data structure to (1) systematically integrate data from various sources, and (2) enable bidirectional data exchange between BIM and EIA. The framework allows designers to run an automated EIA at any point in the design stage and immediately assess the Environmental Impact Score (EIS) of their design choices. A prototype is developed and tested on a case study to indicate the feasibility of the proposed framework. The framework is assessed in terms of functionality, ease of use, scalability, and contribution to raising sustainability consciousness through a workshop with experts. It is shown that the framework is able to quickly provide designers with accurate information about the potential environmental impact of all objects in infrastructure design projects. The workshop with experts showed that the tool clearly makes it easier to perform EIA compared to the existing, highly fragmented, process. This allows the design team to use this assessment on the same level as other design parameters in the decision-making process.