This study shows how the environmental and general theories of economic performance can be adjusted. Existing studies of the Evaluation Model and present conditions for life cycle cost and life cycle assessment of building are investigated in order to establish a new environment estimation model. Life cycle energy consumption and CO2 emission are also calculated by the method of aggregating Input-Output Analysis and results from a field survey. Moreover, a database was set up to record environment loads and costs per item, using life cycle costs per item obtained through investigation. The next stage was to use a computerized program to create the new model from information in the database. It examined the adaptability of the Evaluation Model through two case studies of apartments, using computer simulation. When the Estimation Model and computer program developed in this study is applied to the construction industry, reasonable management of environmental impact is convenient at each step of the construction process. In addition, in the preliminary design phase, it may be of practical use in the consideration of various design and improvement alternatives for environmental effect.