The improvement of the energetic behavior of buildings has turned into a major issue due to the high level of energy consumption. One of the main objectives of the current French legislation, thanks to the definition of a global performance indicator (expressed in kWh/m2/yr), is to reduce the total energy consumption in buildings. In this context, the goal of this work is to develop tools for reducing the use of fossil energy while improving the use of renewable energies. First, the building is represented as a dynamical system and a data acquisition system is developed, which allows the measurement of environmental and energetic parameters, so as to describe the behavior of the building interacting with its direct environment. These measurements will be used by a fuzzy controller whose ability to control and optimize the energetic consumption will be illustrated through the simulation of the temperature control in University’s offices.