In this paper, a mathematical model dealing with a coupled heat, air, and moisture transfer in a building envelope was developed. Based on the three‐following driving potential: vapor pressure, dry air pressure, and temperature, an application on a hygrothermal beha-vior of a real wall was carried out for different climatic conditions. For this purpose, a characterization of the heat and moisture properties of the materials con-stituting the wall made with red brick and cement mortar was carried out in the laboratory. This was used to evaluate experimentally the input parameters of the model as a function of relative humidity. To validate the numerical model, an experimental platform was improved. The wall was set up in a double‐climatic chamber with different boundary conditions, and then the temperature and humidity evolutions were re-corded using several sensors within the wall thickness. The results have highlighted a good agreement be-tween numerical simulation results and experi-mental ones.