There has been significant increase in tall building construction in Turkey in the last decade. As the height of building increase, wind effects become more pronounced. Wind can interact with flexible buildings and can significantly magnify the wind loads and wind induced oscillations. Wind tunnel tests have been widely utilized for estimating the wind effects on buildings. In order to perform a successful test, however, flow conditions inside the tunnel must represent the actual conditions rather closely. In this study, passive devices were designed to create wind profiles defined in wind codes inside Ankara Wind Tunnel that has a short test section. The performance of the designed passive devices was investigated through numerical and experimental studies. Then, wind effects on a rectangular shaped building were examined with high frequency base balance technique. The effect of turbulence intensity, vortex shedding and wind attack angle on wind loads were questioned. Finally base moments calculated from test results were compared with the results of various wind codes.