Tatami / layout - based off 2 Square system works just as well only the types of formed rectangles feature 1., 1.2, 1.25, 1.333 ( known as 3-4-5 right angle ), 1.666 ( Approx to Golden Ratio. Note of interest. After settling on whole number design you go over the mats again this time drawing in the Golden cuts..if two square then 1.618, if 3 square then 2.618. The overall design is a configuration of perfectly fitted Golden rectangles. Walls are then fitted on the Golden cuts