A BIM-based Method for Estimating CO2 Capture of Green Vegetation

EEWH, Taiwan’s green building certification system, comprises of nine indicators, and the Greenery Indicator is designed for estimation of CO2 capture. However, because green area designers need to manually calculate the estimation result, the Evaluation Manual for Green Building simplifies the formula, which ignore the sunlight condition and the differences between species. The Manual mentions that the Greenery Indicator implies huge estimation errors and is thus designed as more like an incentive policy. As BIM technology becomes more mature and more design tasks are carried out on BIM platforms, this study considers the opportunity of using BIM to assist designers to get more accurate estimation without complicated manual calculation. Thus, a BIM-based method for estimating CO2 capture of green vegetation is proposed. Some building architects and landscape architects were interviewed to help identify current design process and existing problems which may be solved with the assistance of BIM technology. In order to identify the feasibility of the proposed method, an estimation tool was developed and used to demonstrate the proposed method in a case study. The proposed method is suitable not only for design of green buildings but also for assessment of existing green area. In addition, two potential issues worth further explorations. First, after design tasks are turned into the BIM-based process, the collaboration pattern between professionals of different disciplines may need to be redesigned. Second, the maturing of simulation and analysis capabilities of BIM technology may help the development of performance-based building codes.