This paper deals with studying of the aerodynamics characteristics in a residential building with a patio system connecting the inside with the outside. The numerical simulation is based on the resolution of the Navier-Stokes equations in conjunction with the standard k-epsilon turbulence model. These equations are solved by a finite-volume discretization method. The comparison between our numerical and experimental results developed using a wind tunnel shows a good agreement and confirms the validity of the numerical method. This proposed design presents an outlining environment suitable building in Tunisia. (C) 2015 Elsevier Ltd. All rights reserved.