Supervision work deals with important data necessary for the performance management on building construction sites in accordance with the Building Act. Therefore, this study attempts to use the data from supervisory reports to measure the performance of private building projects. Performance measurement is important for systematic management. However, there are only a few cases in which performance measurement is performed because it requires strenuous efforts to collect data for measurement. First, this study derived 6 performance areas and 15 indicators through a few rounds of expert group discussions. Then, we confirmed the performance indicators with high feasibility of data collection through a survey of supervision experts. It is expected that the data of supervisory reports can measure systematically performance and assist in speedy diagnosis of private building construction sites.