Construction Industry Act Article 30

Where a construction enterprise contracts a construction project above a certain currency amount or a certain scale, a field director shall be assigned at the jobsite during construction.During the construction period, the above-mentioned field director may not concurrently assume the position of field director of another construction site.The above-mentioned certain currency amount and scale shall be specified by the central competent authority.
中文原文 營造業法第30條
營造業承攬一定金額或一定規模以上之工程,其施工期間,應於工地置工地主任。
前項設置之工地主任於施工期間,不得同時兼任其他營造工地主任之業務。
第一項一定金額及一定規模,由中央主管機關定之。

English translation for reference only; the Chinese text prevails. Not legal advice.