To understand how this story begins, you need to know the difference between two types of window replacement: full frame replacement and insert (or pocket) replacement.
Here is a diagram showing the parts of a window being placed into a new house:
Decades later, that once-new window may need to be replaced.
The easiest way is to take out the old sashes, but leave the frame in place. Then the new window frame is placed inside the old frame (a frame-in-a-frame). The advantage of this method is that it doesn’t disturb the exterior trim around the window and it is quicker and easier. But with this frame-in-a-frame, the size of the glass will be smaller. This is called an insert or pocket replacement.
The other method is to take out all of the original window and to place the new window into the original opening. This requires that the original exterior trim (or moulding) is removed. This method is called full frame replacement. This method requires more labor and is more expensive.
And now back to me and my house…
My house previously had vinyl replacement windows as inserts. The metal wrapping placed over the original exterior trim allowed the trim to continue degrading, so the trim had rotted at the tops of most windows and was in bad shape in other places. I am undertaking extensive work to repair my house and fixing problems rather than covering them up, so I chose to have full frame replacement because that method removes and replaces the exterior trim.
I invited three window companies to visit for an in-house consultation and quote. I was very clear with all three representatives that the rotten trim is a major concern and that is why I decided on full-frame replacement.