Effect of Roof Shape on Wind Response of High- Rise Building Using IS 875:2025 Draft in ETABS

Abstract: High-rise buildings are increasingly common in Indian cities because of limited land and growing population. In such buildings, wind load often controls the design, especially when the building height increases. This study examines how roof shape affects the wind response of a high-rise RCC building using ETABS and the draft provisions of IS 875 (Part 3): 2025. Different roof forms such as flat, sloped, stepped, pyramidal, dome, and tower shapes are compared under the same loading conditions. The results show that roof shape has a clear effect on displacement, storey drift, base shear, and overall wind response. Flat roofs generally show higher wind effects, while more aerodynamic roof forms perform better by reducing pressure concentration and improving flow behavior. The study shows that roof geometry is an important design factor and should be considered during the planning stage of tall RCC buildings.

Keywords: High-rise building, wind load, roof shape, ETABS, RCC structure, IS 875:2025 draft, displacement, base shear.