Hi.

I'm in the midst of a studio build and just thinking about the windows. The building has double glazing (4mm - 14mm gap - 6.8mm) and I was going to then add secondary glazing on the inner wall. Just a couple of questions.......

1) If I add the secondary glazing will I be creating a triple leaf and therefore making sound isolation worse than if I just had the standard double glazing window.
2) If it is still beneficial to add secondary glazing, what thickness should it be? They offer 4mm / 6mm or 6.8mm. Would 6mm be different enough from the 6.8mm in the existing window to negate any resonant frequency issues?

Any advice appreciated

Thanks!

Chris