The Origin and Usage of Luban Rulers—Door Ruler, Formula, and Category

This paper is the author’s second attempt to understand traditional Chinese architectural design, and builds on the author’s fifirst article titled “Chinese Methods of Determining Building Orientations” published in 2019. This article discusses the history of the Luban rulers and their usage to contextualize Fengshui design in Ming-Qing times. Conclusions come from historical literature, site investigation, and data analysis.