Hong Kong’s building density is one of the highest in the world. Since ventilation is a key element in sustainable and environmental design, there is a need to evaluate local wind environments of high dense cities such as Hong Kong. In recent years non-standard curvilinear residential buildings that don’t follow conventional rectilinear block structures are becoming increasingly more popular. Though various studies of ventilation conditions of conventionally design buildings have been made, research of non-standard curvilinear building layouts is still limited. Previous research mainly explored rectilinear block-shaped layouts that typically cause a so called ‘Wall-Effect’ by blocking adequate ventilation on street- and mid-levels around buildings. Our paper presents and summarizes the analysis of airflow and ventilation of non-standard curvilinear buildings based on Computational Fluid Dynamics (CFD) simulations. The Flow Simulation of Solidworks has been used as our analysis software tools. Its technology is based upon the use of Cartesian based meshes and solving the Navier-Stokes equations. Nonstandard and curvilinear shaped building arrangements are categorized into various groups and analyzed in respect to their performance of ventilation on street and mid-levels using a case study of high rise buildings in Sha Tin, Hong Kong. Hong Kong’s climate is subtropical warm and humid in summer, subsequently a higher ventilation is needed and building design has to accommodate good airflow around the buildings. Our findings show that curvilinear buildings lead to a more favourable ventilation environment since they have a smaller wind resistance. Non-standard curvilinear designs perform better in terms of general ventilation since the airflow around the buildings is faster and less turbulent. Our simulations present that convex-shaped buildings have a better overall wind environment than concave-shaped ones. We conclude our paper with a classification of various nonstandard curvilinear buildings that offer a general better airflow and ventilation due to their shape. This classification allows designer to understand quickly wind resistance, airflow, and turbulences that a non-standard curvilinear design has on the immediate environment