An appropriate way to identify the most efficient ventilation systems and improve their design is to use design codes for ventilation rates. These rates are strongly influenced by spatial and temporal fluctuations in wind pressure on the facade and roof. The influence of the effects of wind on ventilation was studied using a model which includes air compressibility, together with the pressure field measured on a model in a boundary layer wind tunnel. The simulation results obtained are analyzed using a design code. The effect of wind fluctuations on the quality of ventilation is evaluated using the concentration of a polluting agent as an indicator. Flow rates measurements have been undertaken in an experimental house near Nantes, in order to allow comparison with computer results. The measurement methodology is described and first experimental results are given in this paper.