The heat loss of a building within a wind flow field results from convection and natural ventilation. Loss from natural ventilation is much more than one from convection, and the former depends mostly on the pressure distribution at the building surface. Therefore, the objective of the present study is to calculate the pressure distribution and investigate flow phenomena, around the building with a rectangular shape in a two-dimensional turbulent flow field. The finite difference method, modelled upon the turbulence $k-epsilon$ model, has been applied to the analysis. The results, followed by the changes of Reynolds numbers, inlet flow conditions, and building shapes, have been also obtained, respectively. Various results of the present numerical analysis coincide qualitatively well with earlier reported empirical results.