A collective house for three sisters and their individual families. The design issue was how to conbine the three protected private rooms and a widely open common space. To keep clear to the south garden, the three story volume is situated at the north side of the site. Within the simple rectangular shape building of the thin concrete frame, there are three private rooms of tube like structure. They define the rest as the common space, in which there are several different conditions according to the floor level, ceiling hight, and the relationship to outside. While each private room has its own door to the common space, two of them on the ground level has its own entrance also for thier private use. The hanging room designed for the single person might be used for the kids room in the future.The ever shifting lifestyle of the contemporary extended family is unpredictable. However, the three dimentional common space will house the simultenious activities. It will foster the identity of the family.