Recently real-estate investment business is standing out as a new plan for creation of source of income. In this paper, we suggested appropriate real-estate investment strategy through the reconstruct case study of existing one-storied building. That is, we showed the efficient process of decision and propel to reconstruct and the key points for lease business and post management after building completion. Also, we analyzed the rate of return of commercial building investment in order to find its optimum dealing time. Therefore the results of this paper are expected to be a help to old ages and persons laying plans for a similar business.