Tatami, the traditional floor covering is still omnipresent in the Japanese homes, even in Western-style villas or in modern block apartments. The tatami mat has a long history: in the beginning, it was used only in the rich houses and only parts of the room were covered… Later, the room became completely covered with tatami mats - a style called zashiki (room for sitting).
The tatami mats are always made in standardized sizes and although the size varies a bit with the region, they are usually about 1.82 meters long by 92 centimeters wide. As a result, the rooms in Japan are also made in standardized sizes, as multiples of tatami mats (for example, a tea room is 4½ mats and a shop is 5½ mats).
Also, some rules appeared regarding the tatami arrangement and an “auspicious” layout was defined. That’s why you will never see a Japanese room with tatami arranged in a simple grid pattern: the tatami corners should not create a cross shape, because that spot will join a number of 4 mats and the number 4 is considered unlucky in Japan, because it is pronounced like the word used for death - “shi".
(Click on the post title for more)