Several types of punching shear reinforcements are available for increase of the maximum resistance against punching shear failure of flat slabs. Conventional punching shear reinforcement in form of stirrups or double headed studs are in use for decades. They are well known due to their simplicity and good performance. A new type of punching reinforcement has been developed for the case, where the flat slab exposed to extreme load and resistance of conventional type of punching shear reinforcement is not sufficient. Another designs point out that new construction system can reduce the amount of CO2. This paper presents some results of parametric study focused on design of the flat slab using different types of punching shear reinforcement and considering the concrete consumption.