In building facades, especially in case of office buildings usage of glass has become quite common. These facades provide a visual connectivity with the exteriors, enhance daylighting and provide better aesthetics for such spaces. Solar protection system for a glazed facade should control the direct solar radiation transmission and avoid the ill effects on occupant comfort. In this context, studies have been carried out in two open plan- conditioned office building of a warm humid climate. In situ experimental measurements accompanied by subjective surveys have been performed to evaluate the indoor thermal and lighting quality along with the performance of the glazing system. Comparative data is acquired from simulation studies for monthly variation in cooling energy with different double glazed windows. Experimental studies are performed to see the effect of sun control films as well as external shading over the double glazed glass in bringing down the heat gain. Parameters which influence the performance of double skin facade are discussed. Air velocities inside the shaft and heat fluxes are measured to determine the efficiency of the facade."