The chumonro (or covered entrance arcade) functioned as a grand entrance for the host to entertain a multitude of guests. The entrance passageway usually led from a main gate to the main house. The function of the chumonro, however, was replaced by trial and error to develop the genkan (or vestibule). It is also important to note that the chumonro represents a division of public and private spaces. The private spaces had no need for an entrance arcade, since the public eye would not look upon it.
The shitomi (hinged wall panels) were rooted in the Heian period. They were hinged at the top by metal rods, flipped down to close, and flipped up to open. The function of these panels was to separate interior and exterior spaces. During the summer, they could be opened to regulate the temperature and light within the space, as well as during the winter they remained tightly shut to prevent the cold, which darkened the spaces. In conjunction with the shitomi, the itakarato (swinging doors) were used as the functional entrance and exit of a space with shitomi. With the advent of the sliding door, quickly these two elements became symbols of the past.
On element that is historically class based is the renjimado (slatted windows) separating the private space of the high-class owner and the public, since it was usually placed at the chumonro of a structure. These windows were slatted with horizontal strips of wood and allowed the person on the interior to view someone on the exterior without being viewed himself.
One of the most important "undeveloped" elements is the
round post. The practice of using these posts changed drastically with
the increased usage of sliding doors. The reason for such a quick evolution
of an architectural element is out of functionality. The round posts did
not make a tight joint with the sliding door, thus the more functional
square posts were used to create an airtight joint. Some residences retained
the use of the round post in public spaces as a symbol of the aristocracy,
but throughout the rest of the building, the square posts replaced its
round predecessor.