The house is known as a 4×4 house because of its dimensions (4m x 4m) and also because it is a 4 story tower.
Regulations regarding shore protection limited construction to a small, 16.5 foot-square space. The biggest problem was creating ample living space on the extremely small site. The more difficult the problem, the more interesting Ando’s design solution is likely to be. Ando has taken a plan, 13 feet by 13 feet (4m x 4m) – the maximum dimensions possible for the site of 4 by 4 house—and created a four-story tower. The entrance and utility room are on the first floor, a bedroom is on the second floor, a study is on the third floor and the living/ dining room (the heart of the house) is on the top floor.