Building information modelling-based approach for aspects of green building evaluation

Green Building Rating Systems (GBRS) have been developed around the world to guide project teams in achieving sustainable building goals. However, the current practice of assessing building sustainability under these rating systems is based on a fragmented process, which relies on paper-based work and manual data input. Building Information Modelling (BIM) technology and design process, on the other hand, are based on the use of intelligent data-rich models, where the required data can be extracted automatically and used to assist green building assessment. This study developed an integrated BIM-based approach for green building assessment that supports GreenRE rating system developed by Real Estate and Housing Developers' Association (REHDA). Initially, an exploratory study was conducted to investigate the current practice of green building assessment under GreenRE and the feasibility of using BIM technologies to tackle the current issues. Then, a BIM-GreenRE assessment method was established based on the match-up of GreenRE requirements and the BIM design process required for sustainability assessment. Based on the conceptual framework of this assessment method, a pragmatic solution consisting of Passive Design Toolkit (PDT) was developed using a visual programming tool called Dynamo. The PDT automates the assessment of two passive design prerequisites under GreenRE rating tool, namely the Overall Value of Thermal Transfer Value (OTTV) and Concrete Usage Index (CUI). Finally, the PDT procedure was tested and demonstrated through a case study, and the generated results were validated against manual calculations. The validation experiment showed a higher automation with greater accuracy during the assessment process of the OTTV (measured 56.24 W/m²) and CUI (measured 0.255 m³/m²) of the case study and this took less than one minute to complete each procedure. This research has established and demonstrated a BIM-based strategy for integrating BIM to the process of assessing building sustainability under GreenRE requirements. The newly developed PDT could be used to assist project teams during the design decision-making regarding building envelop thermal performance such as OTTV, and Concrete Usage Index (CUI) assessment that would enable them to test and compare the performance of several design options early in the design stage