Insulation improvement with replacement windows?
We had an energy audit that showed our 40-yr-old single pane, double hung windows were leaking a lot of air (duh!). But what it also showed was that there was serious deficiencies in the insulation in the walls surrounding the windows.
On the heat-camera it looked like the stud bays right next to the windows on the sides and above often had little or no insulation, while the next cavity over did.
My question is: What kind of replacement window would best address this?
We somehow need to get insulation stuffed (or sprayed) into those cavities while the the actual window is being replaced.