Talking about the cost of producing structural elements made of photocatalytic cement means little since what reaches the market is the finished product: the paint, the plaster, or the manufactured block. Given that the part which interacts with the atmosphere is only the surface, the photocatalytic principle is not used in structural applications, but only where it is possible to maintain limited thicknesses, say from centimeters to a few millimeters. If, therefore, the cost of Italcementi cement containing TX Active® is around 1 Euro/kg, the most significant figure is the cost per square meter of the photocatalytic surface. And so the cost incidence is remarkably low as can be seen from a few examples. To transform the façade of a 5-storey building into a photocatalytic surface, it is enough to add around 100 Euro to the cost of a traditional paint or plaster. Paving in photocatalytic blocks costs on average between 10 - 20% more than traditional paving.