Why are there upturned cornices on the roofs of ancient palace buildings in China?

Cornice, one of the traditional forms of eaves in China, refers to the eaves, especially the eaves in the corner, rising upwards. It is often used at the corner of the roof of pavilions, platforms, buildings, pavilions, palaces, temples and other buildings. The four corners are spread out, such as birds spreading their wings, which is light and lively, so it is often called cornices. Cornice is one of the important manifestations of China's architectural national style. Through this special treatment and creation on the cornice, it not only expands the lighting surface, which is conducive to rainwater drainage, but also increases the upward movement of the building, as if it were a gas that lifted the eaves upward. The cornices in the middle layer of the building complex create a spectacular momentum and the unique soaring and brisk charm of the ancient buildings in China.

Different from the stone buildings in the west, the ancient wooden buildings in China took the bucket arch as the "basic vocabulary". The so-called bucket arch is the overlapping curved wood supporting the eaves, which can expand the vertical force to the horizontal direction, thus constructing various cornices. As the "main sentence pattern" of ancient architecture in China, there are many types of cornices, such as drooping, upright and overhanging. Their different forms create different artistic effects, either light, simple or majestic. Pavilions, pavilions and buildings should use cornices to identify themselves and express their feelings. The height and length of cornice often become the difficulty and focus in architectural design. As the saying goes, "adding one point is too long and subtracting one point is too short", its design must be just right, so as to be light but not frivolous, simple but not mechanical, dignified and not rigid.

Cornice is an important part of traditional building roof modeling in China. Among the traditional buildings in China, the shape of the roof is the most prominent, and the roof accounts for a large proportion in a single building, which can generally reach about half the height of the facade. The beam-frame combination of ancient wood structure can naturally make the top of the slope form a curve, not only the slope surface is a curve, but also the front ridge and eaves end, and the eaves can also be added at the corner where the eaves turn. The huge roof composed of beams and frames, as well as the gentle curve of the top of the slope, the straight roof ridge and the upturned cornice, make the roof the most remarkable form feature of China architecture.