Thanks guys, looks like the home survey is the place to start. The windows are less than 5 years old. I am not sure if any insulation was added at all as they were installed before I moved in. I will get the survey ordered and post the results online!
Knowing replacement window contractors in this area like I do...I doubt they did anything at all. Most of them cut the old out behind the casing, slide in the new, cover the exterior damage with aluminum...sometimes they actually caulk it.