Leakage in the building envelope may occur airflow as well as its surface. It brings series of adverse consequences, including the flow of diffuse. The airflow building envelope is allowed through a pressure gradient, which is caused by the difference in temperature and wind effects; if necessary a mechanical ventilation system. Article introduces the analysis which was performed on experimental objects of different wind exposition in situ. In this analysis was measured pressure, relative humidity and air temperature in the interior and exterior, for a period of one year. In the conclusion is evaluated the effect of these boundary conditions on the very existence of the airflow through building envelope.