In this study, it is assumed next that both BEC and BEL are both implemented in Thailand. A rolling
plan is also carried out for code and energy label revision every three years. The procedure is adopted in practice in various countries. As shown in Table 5, building energy label would comprise with 5 energy performance levels. The performance of Label No.2 corresponds to the mandatory BEC requirements whilst that of Label No.5 represents the highest energy performance level of the building at that time. The terms "CODE", "HEPS", "ECON" and "NZEB" in Table 9 are referred to the performance levels as described in Table 6. The performance level of "CODE+" is laid between that of "CODE" and "HEPS" and so on. It can be observed from Table 5 that the mandatory BEC requirements will be strengthen from "CODE" in 1st period to "CODE+" in 2nd period.