This study is case study about 3-stories mini detached houses by small scale developments located around the centre of city in Osaka. The intention is to investigate the possibilities and the problems as urban houses with low-rise and high-density grounding style. By the questionnaire to residents and visiting investigation, ‘process of acquisition’, ‘plan and living style’ and ‘actual situation of enlarging and repair were understood. The result of analysis, tree characteristics of space ‘narrowness’, ‘individuality’ and ‘countermeasure for car’ and three characteristics of gathering ‘disregarding the direction’, ‘facing each other’ and ‘openness of first story’ were extracted.
