It provides scale and proportions to the Japanese house, the tatami, which was introduced in the 16th century, under the Bakufu administration in Muromachi. Made of compacted straw edged with braiding, it is, a basic soft flooring. From this simple elements grew the whole concept of standardized architectural components. Heavy roofs were supported by wooden structures resting on pillars measuring eleven centimeters by eleventh centimeters across. The distance between the pillars was equivalent to the width of four tatami mats.