Office building that stands in the big cities are classified into commercial buildings that can absorb electrical energy usage of more than 17% of the total
consumption of electrical energy in Indonesia. Usage of office building that has the constant type of activities and operational time, making the office building as
an interesting object to be energy consumption controlled. To control the energy consumption, then the measurement of passive performance of building through
the Overall Thermal Transfer Value (OTTV), and active performance of building through energy consumption intensity (IKE) assessment needs to be done. After performed simulation using software EnergyPlus, in order to determine the IKE assessment of basic case office building model that interpret office building in Indonesia in general, obtained value of 237 kWh/m2-year for small office building and 251 kWh/m2-year for big office building. In addition, it also conducted calculations on the value of OTTV to determine the passive performance of building and obtained value of 42,1 W/m2 for the wall composition of basic case office building model. After knowing the results of IKE and OTTV for basic case office building, then made models for efficient case office building through energy conservation, then obtained IKE value of 152 kWh/m2-year for small offices and 159 kWh/m2-year for big offices.