Energy consumption is very much to achieve comfort condition in buildings. Therefore, using and finding methods are necessary to reduce building energy consumption. First, the building energy consumption must be calculated. Computer Simulation is a method to calculate building energy consumption. In this paper energy consumption of an education building has been calculated using Energyplus software in Isalmic Azad University Tabriz branch. This building has more energy consumption according to geographical type of Tabriz city. Several parameters of this building have been changed to reduce building energy consumption. The result shows that, in optimized building, energy consumption reduces about 35.5 percent in winter, about 42.22 percent in summer and about 40 percent (3.82E+12 joule) in year. In addition, the building parameters had been changed according to minimum building cost. The result shows that, in optimized building, energy consumption reduces about 35.5 percent in winter, about 42.22 percent in summer and about 40 percent (3.82E+12 joule) in year. In addition, the building parameters had been changed according to minimum building cost.