This study investigates lifestyles in large-scale, newly dwelling houses in the Tokyo Metropolitan area, focussing on the transformation of seating style within the home. The study demonstrates that trends in changing lifestyle pattrens result in physical transformation of the home that are linked to family and personal history, disposition of furniture in the home, presence and location of Japanese vs. Western rooms, and overall floor plan structure. This part of the study identifies five evolutionary directions in contemporary Japanese lifestyles, which are related to ways in which Western-style furniture was introduced to the home.