A room may start to feel colder. The windows may look cloudy. You might notice condensation trapped between the panes, or feel draughts around the frame. These are all common signs that the glazing may have failed.
Both have their place. Double glazing remains the standard choice for many homes, while triple glazing is often seen as the higher-performing alternative for those who want the strongest possible insulation.
The real question is not always whether triple glazing is better on paper. It is whether your home actually needs a full new window system, or whether upgrading the glass alone would achieve the result you want.