I work in this field.
If it's purely sound insulation, undeniably secondary glazing is the best option, with a sheet of 6.8mm Laminated glass, as the pvb interlayer stops sound waves, and the increased space between the internal pane of the window and the secondary glazing (suggested around 150mm) improves performance way and above a triple glazed sealed unit.
However, secondary glazing is expensive and unsightly.
If you're looking to replace with a decent triple glazed composite system, I'd suggest over £400/m2, as the cheaper systems such as Velfac are poor. We sell Rationel and Internorm.
You can get triple glazing in standard PVC windows, but as the overall sealed unit thickness is quite small, sometimes 32mm, sometimes 36mm, the cavities aren't very large, hence sound and heat insulation performance is poor.
If it's purely sound insulation, undeniably secondary glazing is the best option, with a sheet of 6.8mm Laminated glass, as the pvb interlayer stops sound waves, and the increased space between the internal pane of the window and the secondary glazing (suggested around 150mm) improves performance way and above a triple glazed sealed unit.
However, secondary glazing is expensive and unsightly.
If you're looking to replace with a decent triple glazed composite system, I'd suggest over £400/m2, as the cheaper systems such as Velfac are poor. We sell Rationel and Internorm.
You can get triple glazing in standard PVC windows, but as the overall sealed unit thickness is quite small, sometimes 32mm, sometimes 36mm, the cavities aren't very large, hence sound and heat insulation performance is poor.
