Previous studies have revealed significant differences between the theoretical and real energy consumption of buildings. These differences can be associated with the use of space heating and ventilation systems. The main difficulty is to simulate manual operation of the heating and ventilation system and to achieve results that approximate reality. The aim of this paper is to present the initial stage of the generation of a calculation model based on the space heating energy use. The generated model, works with free temperature (floating). It incorporates some of its occupants practices related to the use of energy systems. Subsequently, the results are compared with the information obtained in dwellings studied. This paper presents the model and its validation with the first 7 houses. Using a classical model, significant differences were obtained. By contrast, with the proposed model the difference is much smaller, when compared with experimental data. In the future, it is expected to identify the variables and parameters that have the min influence on the model. Thus, it is expected to achieve the calibration of the model and future generalization to other dwelling types.