A small, rustic style tea ceremony structure up to 4 1/2 mats *yojōhan 四畳半, used to perform a simple, quiet tea ceremony. The word sōan, literally meaning grass retreat, is derived from the thatched roofing of rural dwellings. The style of the sōan exemplifies the taste for calm *wabi わび, achieved by the use of subdued colors, and plain, untreated natural materials. In such surroundings, purposely removed from the bustle of daily life, tea ceremony participants could enjoy feelings of solitude and being at one with nature. Swords were left outside because the tea ceremony hut was intended to symbolize peace. Theoretically at least, rich and poor, high and low became equal for a short time.
Prior to the use of the sōan, during the Muromachi period, host and guests performed the tea ceremony in an area of about 5 to 6 mats, in one corner of a large room, partitioned off by screens. Even during the time of Murata Jukō 村田珠光 (1423-1502) and Takeno Jōō 武野紹鴎 (1502-55), considered to be the founders of the tea ceremony, the rustic sōan style had not yet gained popularity. Sen no Rikyū 千利休 (1522-91) is generally thought to be the tea master who firmly established the sōan.
An important text is the *Nanbōroku 南方録, believed to have been written by Nanbō Sōkei 南坊宗啓 (?-1624?) living at the temple Nanshūji 南宗寺 in Osaka. He was a close follower of Sen no Rikyū. It states that according to Rikyū, the best rustic hut should be 2 mats large, nijōdatami 二畳畳, with one mat for the host and one for the guest with the firebox *ro 炉 cut in a corner of the host's mat *temae datami 点前畳. The Nanbōroku goes on to say that with each increase in mat size in the tea ceremony room, the rusticity of the sōan diminishes. When the sōan style is mentioned in the Nanbōroku, it usually refers to a 3-mat room or smaller. The upper part of the host's mat expresses the idea of the kitchen, in that the ceiling above that area is lower that the rest of the ceiling, and is often covered with straw matting. The guests' area has a thin board ceiling or a ceiling covered with split bamboo wickerwork *ajiro 網代. The rest of the ceiling is slanted and exposed, and may have a skylight *tsukiagemado 突上窓. The skylight can be opened by pushing it up with a prop that also supports it. These windows were often made of bamboo lattice entwined with vines *shitajimado 下地窓, or lattice strips forming variously spaced patterns *renjimado 連子窓. The crawl-in entrance *nijiriguchi 躙口, and simple firebox, ro, are also important attributes. Example: Myōki'an Tai'an 妙喜庵待庵, Kyoto.