Building certification systems (hereafter referred to as certification systems) have been the basis for improving building performance. Demands for buildings has been gradually diversified according to the changes in the social environments, which also have been reflected into diversified certification systems. Diversification of certification systems is inevitable in order to guarantee building performance above a certain level that meets the rapidly changing social demands. However, an excessive number of certification types and redundant processes among various certification systems can pose adverse effects.

The current laws and regulations mandate a total of six certification systems depending on the use and size of a building, which are operated in parallel with eight building standards. Each certification system has been introduced with its unique purpose. However, the certification systems have been operated for an extended time, and certification criteria introduced on the certification systems later time could overlap with those on other systems. Excessive building standards and certifications required for a single building can be regarded as obstacles for the growth of construction industry due to the cost and inefficiency.