A tea ceremony room *chashitsu 茶室 distinguished from a genuine tea ceremony house, and points to buildings in the tea house style, or buildings in sukiya style *sukiya-zukuri 数奇屋造, or include both, and call them sukiya. However, the distinctions are not clear. Historically, sukiya zashiki 数寄屋座敷 in Bunrui sōjinboku 分類草人木 (1564) could be seen as an early example. A tea ceremony room was usually called *zashiki 座敷 or referred to by the number of its mats. Heinouchi Yoshimasa 平内吉政 and his son Masanobu 政信 (?-1645), famous carpenters in the Edo period, state in their secret book *Shōmei 匠明 (1608) that calling a tea ceremony room a sukiya began around the time when the mansion Jurakudai 聚楽第 was being built for Toyotomi Hideyoshi 豊臣秀吉 (1536-98) in 1587.
The use of the word sukiya is thought to have originated by Sōeki 宗易 (Sen no Rikyū 千利休, 1522-91) in Sakai 堺. Nevertheless, it is certain that the name sukiya was used by Sen no Rikyū in place of zashiki or *kozashiki 小座敷 (small room), or enclosure *kakoi 囲, within a large room. During the Keichō 慶長 era (1596-1615), the use of the term sukiya became popular. Especially used at Furuta Oribe 古田織部 (1544-1615) and Kobori Enshū's 小堀遠州 (1579-1647) tea ceremony, it seems it was a custom to call a small room a sukiya in contrast to larger rooms, *shoin 書院 or *kusari-no-ma 鎖の間. The Sen family, Senke 千家 was critical of this trend, and Rikyū's great grandson Kōshin Sōsa 江岑宗左 (1613-72) stated that: To call a tea ceremony room sukiya is offensive to hear, so it should be called kozashiki, as in the past. We avoid saying sukiya. Thus, around this time, an effort was made to distinguish kakoi from sukiya.
The Chafu 茶譜 says: The word sukiya was not used in the Rikyū style, and the tea room was called kozashiki. Kozashiki is a separate building that guests enter through a small door kuguri くぐり from the tea garden *roji 露地. An enclosure kakoi means an enclosure that has sliding paper doors *fusuma 襖, which were placed in a shoin room to enclose a special area for fixing tea. This was accomplished by using partitions. There was an alcove, a small entrance, a middle post, a push up window, a back door way *katteguchi 勝手口 and an owner's entrance *kayoiguchi 通い口. Further, the Chafu states that sukiya and kozashiki were built independently in tea gardens.
Examples: Nishihonganji Kuroshoin 西本願寺黒書院 (late 16th century), Manshuin Koshoin 曼珠院小書院 (mid-17th century), all tea houses at Katsura Rikyū 桂離宮 (mid-17th century), all in Kyoto.