There are two essential management objectives in the construction industry: improvement of construction speed and reduction of materials used. A representative attempt to achieve these objectives, method of unit modular construction has been actively applied in many developed countries, including Japan. The unit modular technology is a method by which a house is assembled and completed on the site based on housing modules that are manufactured in a factory. Korea, a relative newcomer to this field, has secured design and construction technologies of a structure equivalent to a detached house, and is pursuing the research and development of the design and construction technologies in order to expand its horizons. The major objective of this study is to propose an economic feasibility forecasting model and to apply the model for method of unit modular construction which is now under development. This study concludes that compare to the traditional method, the method of unit modular construction is recommended from the life-cycle cost viewpoints.