Anyone who has tried to make a call inside a modern building or checked messages on a train knows the feeling. The moment you step indoors or take a seat by the window, the signal weakens, pages load slowly, and calls start to break. It happens so often that it feels like a normal part of everyday life. The root cause, however, is not the mobile network outside. It is the building or vehicle itself. Modern glazing is designed to manage heat and improve energy efficiency, and