A few things all tearooms have in common is that the floor is covered with Tatami mats. Usually there is an alcove or Tokonoma in the room, but its size may vary.
There are different sizes of rooms which have names according to the number of Tatami mats in the room or the layout of the Tatami mats. For example, a four-and-a-half Tatami mat room is called a Koma (small room)
There is no fixed layout, as to where the door has to be in relation to the host’s mat but the guests should be seated next to or near the Tokonoma so the host’s mat cannot be in the same corner.
1 Sadouguchi ( 茶道口 ) (Host's Entrance) The Sadouguchi is a full-sized door the host uses to enter and exit the Chashitsu carrying utensils. Commonly, a Taikobusuma sliding door is used. The Taikobusuma is comprised of a lattice frame with white paper affixed to both sides. There is no knob or handle, and the door is simply pushed open by hand.
Another sliding door is called a Fusuma. A Fusuma is a standard sliding door in old Japanese houses. Sliding doors have been used for hundreds of year in Japan because of the advantages in room design and feeling of space.
2 Tokobashira (床柱) ( Supporting pilar ) Much care is put into crafting the Tokobashira supporting pilar, for it is almost like the face of the Tokonoma. High grade wood or that which conveys an air of sober refinement (Wabi) is used. Red pine is sometimes used as Tokobashira and the bark could be left on. The pilar located on the opposite side from the Tokobashira is called an Aitebashira or partner pilar.
3 Otoshigake (落としがけ)( Tokonoma Lintel ) The Otoshigake is the lintel that supports the partial short wall in front of the Tokonoma alcove. It is commonly made of red ceddar, red pine, or Paulownia wood. A nail or hook is hammered on the surface of the center of an Otoshigake, and sometimes the back, and a small hanging vase with Chabana can be hung from it.
4 Kakejiku (掛軸)( Hanging scroll ) In these scrolls, calligraphy or painting are usually mounted. Calligraphy includes such as Waka poetry, letters and Zen phrases written by monks, while paintings are about landscape scenery, flowers, birds and so on. Vintage brocades used for the frame shouldn't be missed. Guests can see the point of the day's tea ceremony. On this hanging scroll is a prase describing the summer season.
5 Tokogamachi ( Tokonoma bottom beam )
6 Temaeza ( Tea master's tea mat ) This Tatami mat is only used by Teishu to prepare tea and re-light the charcoal fire. Kyaku may sit on all other Tatami as will be instructed by Teishu. A Temaeza is just the same as other Tatami in the room. However, sometimes Temaeza can be a little shorter when a screen or short wall is present, depending on the size and style of the Chashitsu.
Nijiriguchi (にじり口) (small crawl through opening) : A Chashitsu should have a Nijiriguchi in the outer wall for the guests to enter through. When entering the Chashitsu through a Nijiriguchi, Shoes or sandals should be removed. A Nijiriguchi is so small that one has to crawl in on all-fours, placing hands clinched into relaxed fists on the Tatami first, one slides in on the knees little by little. depending on the size of the room and the place one is supposed to be seated, one should either continue sliding toward that location or otherwise walk there. The last person should close the sliding door of the Nijiriguchi. Usually when attending a Chaji, everyone will first Haiken the Tokonoma, Chabana, and Kama (in this order), before sitting down. Incase of a Chakai where many people will enter the room, only the Shokyaku will Haiken and the other guests will pass Haiken to save time.
Tokonoma() (Alcove) : An alcove in the tea room where the hanging scroll (Kakejiku) is hung and flowers (Chabana) are displayed. A Tokonoma is considered the most important place in the room and thus the chief guest or Shokyaku will be seated nearest to the Tokonoma.
Variations of a Chashitsu
Nijo Chashitsu a two mat room with fire pit build into Temaeza mat and a 3-inch (7.5 cm) board behind it.
Naga-yojo Chashitsu Rectangular four-mat Chashitstu with fire pit between Teishu and guests.
Nijo-Daime Chashitsu Daime-style Chashitsu with two guest mats plus a shorter mat for Teishu. Fire pit is between Teishu and guests.
Hira-Sanjo Chashitsu Three mat Chashitsu with fire pit between Teishu and guests.
Yojohan Chashitsu Four-and-a-half-mat room.
Ichijo-Daime Chashitsu Daime-style with one guest mat and a short mat for Teishu. Fire pit is build into Teishu's mat.
Fuka-Sanjo Chashitsu Three-mat Chashitsu with fire pit build into Teishu's mat on the wall side with a 45cm board.
Old-style Naga-yojo Chashitsu Old style rectangular four-mat-room with a fire pit between Teishu and guests, but witha 15cm board.