Building Integrated Photovoltaic (BIPV) technology is an immerging area of recent development which has a high potential to be implemented in urban areas. PV panels of BIPV system serve as structural elements and are required to be fixed at optimum tilt angle for maximum insolation. For open fields with no obstructions, HDKR (Hay, Davies, Klucher, Reindl) model is employed effectively for calculating the optimum tilt angle. For urban areas, it is required to consider the adverse effect i.e., shading and sky view blocking of building for accurate calculation of optimum tilt angle for determining maximum insolation. This is an attempt to calculate optimum tilt angle of a BIPV panel surrounded by buildings of different heights which are located at different radial distances from panel by employing modified HDKR model. The present mathematical model gives accurate insolation values as it accounts both shading and sky view blocking effects. This sky view blocking effect is expressed by a factor and is calculated by integrating the sky trapped curve plotted for any given tilt angle of the panel. Optimum tilt angle and insolation of BIPV panel are presented for different state capital of India by considering shadow effect because of surrounding buildings.