It is essential to investigate the pressure distribution, aerodynamic coefficients and wind flow fields in-order to predict the wind loads and wind behaviour in building environments. Most of the investigations and international wind load standards haven't highlighted the wind load and wind environment on-and-around buildings under different terrains. The main objective of this investigation is to explore a practical numerical approach for the accurate estimation of wind loads and their impact on buildings under different upstream conditions. In this investigation, simulations are done in IDDES turbulence model along with the formulation of kω SST using CFD. Results indicated the influence of ground roughness in pressure distribution on building faces. Furthermore, CFD results over-predicted the experimental values near the edges due to strong shear-flow and expanding wake-vortices. The cross-validation of the mean drag coefficients showed good-agreement. Hence this investigation promotes the practice of IDDES in wind-resistant designs for tall buildings. Copyright © 2020 Inderscience Enterprises Ltd.