The most suitable methods for increasing the climate resistance of buildings on hot summer days are intensive ventilation and effective external shading. However, it is possible to discuss what kind of approach used, while simulating the control of these two elements in energy simulation programs, to make the result as much representative as possible. We created and compared three different control modes for this purpose. The basic mode represented models created from monitoring of habits of building users, while the second mode represented an automatic system based on sensory control. The third mode represented models that provide an early warning system against a series of hot days. They intervene in windows and blinds control for a several days in advance. The base mode using the schedules reached more than 2 °C higher maximum indoor air temperature than the two others in a direct comparison of these three systems by simulating a simple building. It also has been shown that with a relatively simple early warning system, it would be possible to replace an even more complex automatic system.