In this study, the model of an exemplary highrise building was subjected to various experiments in the wind tunnel and the surface pressure distributions brought out by the airstream over the building at different velocities and angles of attacks were investigated. Wind forces on the windows in the critical pressure zones were also figured out. In the first hand, a 1:300 scale model of the exemplary highrise building was specifically designed and manufactured for the wind tunnel experimentation. Subsequently the experiments were conducted in the wind tunnel of Faculty of Engineering and Architecture of Gazi University. The model was positioned in the working section of the tunnel which has a cross sectional area of 305×305 mm so that one face was either normal to or directed 45° towards the flow direction during the testing. In the experiments, dotted pressure readings formed on the cross sectional surfaces of model depending on the velocity and direction of the blowing wind over the building were recorded and the pressure distribution profiles around the model cross sections were examined and the critical wind forces formed by the local pressures on the windows were calculated. In the last stage, a method of error analysis was searched and identified for processing various sets of experimental pressure data. Consequently, polinomial regression technique which transforms these sets of pressure data into a continuous curve passing through the vicinity of the data points with minimal error were applied as a method of error analysis. Pressure profile graphics related to the relevant cross sections were obtained by employing this technique.