In Malaysia, Green Building Index (GBI) is one of the sustainability rating tools for the construction industry, focusing on six main categories including Energy Efficiency (EE), Materials and Resources (MR), Water Efficiency (WE), Indoor Environment Quality (EQ), Sustainable Site Planning & Management (SM) and Innovation (IN). Currently, the process for GBI assessment and certification is carried out manually, which requires additional time and effort for preparation of supporting documents. Since Building Information Modelling (BIM) is perceived as a holistic solution for digital integration of various construction project attributes, it is anticipated that sustainability aspects can be addressed through BIM if an appropriate approach is implemented. Therefore, GBI assessment process can potentially benefit from BIM application to transition from conventional manual approach to an automated approach. This research is aimed at developing an Automated Green Building Assessment tool (AGBIA) using visual programming (Dynamo) to run as a supplementary application to the existing BIM authoring software (Revit). The AGBIA system consists of 6 modules that automatically analyses digital BIM models in accordance to GBI requirements, and ultimately produces the necessary documentation as a final output. AGBIA is an efficient supporting BIM tool as compared to assessment and documentation of green building data manually.