EIBS which controls the HVAC systems is one portion of Intelligent Building in buildings. Its performance is directly related to the amount of energy consumed in a building and the comfort of the building occupants. One approach to evaluate the performance of an EIBS is through the use of an Emulator. This is a special computer/data acquisition system that is connected to the sensor inputs and command outputs of the EIBS. It replaces the HVAC system and building and use a computer program to simulate their response to EIBS commands. This report contains guidelines to design the emulator and present its design example. (author). refs., figs., tabs.