jǔjià
- Scope note
- Meaning, literally, to raise and build up, jujia is the method of positioning the purlins within the roof frame, layer by layer, in order to determine the pitch of the roof. The term mainly appears in the Gongcheng zuofa (1734) and Yingzao suanli edited by Liang Sicheng, so it can be considered part of the official practice of the Qing dynasty. Different from juzhe 舉折 described in the Song dynasty Yingzao fashi (1103), jujia is the process of determining the height of the roof ridge based on the heights of the purlins as calculated from the bottom (eaves) to the top (ridge). Here jugao 舉高 refers to the height that a purlin is lifted relative to the one below it. The jugao of each purlin is determined by the percentage of the distance of bujia 步架, the distance between two adjacent purlins. For instance, “65 ju” ( 六五舉) means that the height of jugao is 65% that of the bujia 步架. The first step is to determine the height between the top of the neighboring pillars, guazhu 瓜柱 post, or tuodun 柁橔 brace. Then add the appropriate height of pingshui 平水, and this will result in the appropriate position for the purlin. As outlined in the Yingzao suanli, the calculation of jugao differs according to the number of purlins in a given building. Few actual buildings correspond exactly to the method of jujia outlined in the Gongcheng zuofa and Yingzao suanli, indicating that the height of the purlins could be increased or decreased according to specific circumstances rather than always rigidly following a single standard that was documented in these texts.
- Date of creation: 28-Oct-2024
Accepted term: 28-Oct-2024 
