Research and development at Brno University of Technology, Faculty of Civil Engineering is focused on the experimental assessment of modern timber structures. For the assessment of the influence of different timber structures on indoor environment a comparative method is used. This method is based on the measurement of indoor environment parameters in the experimental house. There are 4 test (reference) rooms, each of them having the same geometry but a different light-weight composition of envelope which are flexible at the same time.

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.