For a long time, Taiwan residents extended housing spaces in order to suffice their living demands and provide an ideal living space which they imaged. The rate of housing extended space in Taiwan is 65.9% . For understanding the state of housing spaces extending phenomenon in Taiwan, the task of this study is investigating the formats and reasons of Kaohsiung housing extended spaces by the questionnaire and analysis. The results of this study indicated five of these findings are worth summarizing: ˙ The main sources of disobeyed spaces are the vacant by building coverage ratio, included the front of the house, the behind of the house, the side of the house, the flat roof, the balcony etc. ˙ The purpose of housing spaces extended to increase the use of spaces, the space functions mostly were laundry rooms and stockrooms. ˙ Most sizes of the disobeyed spaces were one floor of the metal shacks. ˙ The regulations of building coverage ratio, floor area ratio have some flows and let the residents to construct the disobeyed space. ˙ The mechanisms of the housing market and building design became the factors of the disobeyed house afterward. Besides strengthen the inspection of the disobeyed constructs to prevent disobeyed house, it is proposed to proceed from the following two strategies. First, revise the vacant of BCR and FAR and architectural design standards. Second, revise the mechanisms of the housing market and architecture plan.