If you’ve ever had the opportunity to visit a private home in Japan, you probably remember the scent of tatami floors. In the summer time in Japan, stepping out of the sun’s heat and the daily activity on the street, into a quiet shady room floored with tatami is somehow soothing. I suppose a combination of the cool green color that can fade to a warm yellow over time, the grassy scent, and the texture of its woven surface that is both soft and forgiving to sweat.
Tatami is one of the main flooring materials used in traditional Japanese architecture. Originally made from rice straw and rush, it was first used by nobility in the 12th century as seating and sleeping mats placed on wooden floors. These early mats were taken out when needed and could later be stored away. During the late 15th century tatami became more widely available and affordable and they were used as a permanent floor covering for an entire room.
While the use of tatami has waned over the last few decades, it is currently experiencing a resurgence in popularity. In Japan today, most modern homes and apartments have at least one room that is floored with tatami. They require a little more care than your average vinyl flooring, but its hard to argue all of the benefits they give in exchange.
The exact dimensions and character of tatami have always varied slightly from region to region, but in general, standard tatami are rectangular in shape with a consistent 2:1 ratio measuring roughly 1 x 2 meters large and 5cm thick. At this size, a single tatami mat can accommodate one person lying down, or two people seated side by side. The panels are made mainly from layers of rice grass and woven rush and are manageable for one person to carry.
Over time, tatami became a standard module of Japanese architecture with columns spaced according to how many tatami mats could be laid between them. Interior rooms were also sized according to the tatami module. Even today in Kyoto, interior room sizes are referenced according to how many ‘jou’ they are, a unit that describes the size of one tatami mat. It seems that over time this modular understanding of spatial units has stuck and you will find even today that architects in Japan often use gridded paper to sketch out plans in meter modules. While they may not be designing for tatami rooms, the visual of one tatami I think is always there as a quick mental reference point when sizing a space.