This is probably a question for Dana, our resident insulation guru it seems.
When there is condensation on the interior of a insulated windows, does it mean that the window has lost it's insulation...

I bought a weekend project house and it's got a bunch of older insulated windows and a couple of brand new Kolbe windows in them.

Moisture on windows I thought was part of the humidity created when cooking, etc and it's cold outside.
What I'm noticing as I pay closer and *plan* is that the newer windows have nary any moisture on them but the olders ones have quite a bit.

I still need to decide on a plan on opening and insulating these walls if I choose. These old plaster walls have seen better days. I'm just avoiding the wire and lath I suppose. The interior walls are great and are concrete hard. The walls facing the exterior are crumbling in some areas, and in others, I can see moisture or dew is getting to it. It's a brownstone, so I'm not sure if the moisture issues are just uninsulated walls and the temperamental difference to the plaster that is causing the moisture...