Space cooling and heating are needed throughout the year for commercial buildings and electricity use in these buildings accounts for about one-third of the total energy consumption in Turkey. In this study, Adnan Menderes International Airport (ADM) located in Izmir is simulated with EnergyPlus software which is a new generation building energy analysis tool. The simulation model is constructed first with Design Builder and than the measured data are used to compare the model. EnergyPlus simulations are used in this thesis to help understanding more about the ADM.s dynamics and evaluate various strategies such as different orientation and heating, cooling, ventilation and air conditioning (HVAC) system. According to simulation and different HVAC system results; cooling electricity consumption increases 2.8 times in each month. According to simulation and east orientation results, heat gains decrease between 2% and 11% in winter, autumn and spring months and increase between 3% and 14% in summer months. Measured data of ADM building showed that HVAC system had constituted almost 80% of the total energy consumption, according to the average data obtained in 2008. The difference between measured and simulation consumption values are greater more than 70%. According to simulation results, also there is 2.4 times more electricity consumption on 18 August when compared to 11 January. Finally, analysis showed that ADM building requires year-round cooling and very little heating.