Abstract
We carried out a simulation for a combined building for owner use and apartment house that will fit any lifestage of long-staying owner's family in the urban area. We found out that when we plan a combined building, the renting part should not consist all of one-room flats. It became clear that by containing at least one unit for family use in the renting part, the owner's family can choose whichever place, their own place or the flat for family use, that is most suitable for their lifestage.