This paper presented the aerodynamic modification of 1:1:4 (l:b:h) tall buildings having horizontal and vertical-type duct openings inside the buildings to harvest the wind energy. The study considered nine different models of the square-plan area. Initially, a 1:1:4 square-plan shape tall building model is considered for the validation and grid sensitivity study in the Computational Fluid Dynamics Method (CFD). Square and circular shape duct openings are considered inside the regular shape and setback-type shape tall building models. The velocity inside the considered models’ horizontal and vertical-type duct openings is compared. As the study focused on harvesting wind energy, wind velocity inside the duct shape of the different models has to be noted. This study also focused on the drag and lift coefficients along wind angles. The circular-type duct opening model increases wind velocity by 92% compared to the square-shaped duct opening. The setback-type duct opening model creates 28% less moment and decreases 32.2% drag compared to the regular shape model. This study may be considered for the corner modification of the buildings, change of different geometrical shapes, and multiple number of openings.