This paper addresses the spatial composition of Tatami rooms designed by Seiiti Sirai（1905-1983）, focusing on the ceiling forms. Sirai has been regarded as one of representative architects in Japanese-style and the unique example of them.
Almost all pre-existing types of room-sections appeared during his early period, but the combinations of section-types tended to become more complicated year by year.
Additionally, in many examples the ceiling plan and the floor plan had different spatial systems, and they could be classified mainly in terms of the function of the ‘divided space’, which was formed by different ceiling levels in the room. And we could recognize a tendency that the features of each type were integrated gradually into one prototype. Specifically, ‘Divided space’ was set around Tokonoma and entrance of the room, high ceiling was connected to the main opening, and in some cases, the order of the next room came into the room. These features were seen in especially Saku-Setsu-Ken (1968) and Un-Pan-Kyo (1984), and we could regard them as the most developed composition in the Tatami rooms designed by Sirai.
Spatial Composition of Tatami Room Designed by Seiiti Sirai ーFocusing on the Ceiling Forms