This paper aims to make research on the difference of the times, when children's bedrooms separate from parents' ones, and when each of children's bedroom isolate from brother's one, according to the planning types of dwelling units. The questionnaire on 764 samples in 17 planning types, 3LDK and 4LDK, shows such results as follows. The times for separation and isolation have relation to the number of rooms, the floor space of LDK rooms, the daylight of LDK rooms, and the number of rooms next to LDK rooms in these dwelling units.
