Visual Req calculation tool for green building evaluation in Taiwan

Abstract The Ratio of Equivalent Transparency (Req) is a basic index for assessing whether a building is energy-efficient in Taiwan. Req is the ratio of the area of total building envelope and the area of envelope equivalent transparency. Calculation of Req requires not simply the consideration of natural factors such as building location, direction, ambient lighting and sunshine, but also and physical factors such as material, structure, ventilation and sunshade. Current practices in Taiwan of manually calculating Req render the results prone to error, and are also time-consuming. Therefore, this research developed a visual Req calculation tool based on a 3D environment. This system provides users with various visualization tools to view the status and Req results of the building project. Furthermore, object-oriented modeling and parametric design can shorten the time taken to look-up tables and simplify the process of Req calculation, and also help to reduce computation time and errors.