Our builder has just fitted some double glazing. I have no issue with the quality of the units but am concerned at the size of the gaps between the window surround and the frame of the double glazing unit. Some sides the gap is over 3 inches. The gap has been filled with expanding foam and a upvc cover placed over the foam. Should I be concerned? I believe the builder should have measured the window better. Will this solution to the gaps last. I,m concerned that the foam will degrade within a few years and the work need to be redone.