I'm considering adding exterior insulation when I replace my siding, but I'm wondering if I need to reinstall my existing windows. They're in poor condition and need replacing soon, but I'd like to wait a few years to do the siding and roof. If I replace the windows now, will I have to do a lot of rework when I eventually add the insulation?
3 Answers
While you can leave the windows in place, I recommend pulling them out if you're doing exterior insulation. This way, you can extend the rough openings to match the new exterior face, which helps prevent water leaks that could occur if you just seal them with caulk.
You won't have to reinstall your windows if you do the exterior insulation later. You will need to remove the siding and window trim to add the insulation, and you'll have to recaulk everything and put the trim back, but the actual windows can stay put since they're mounted to the frame.
You can actually box around your existing windows and finish with trim or flashing. Some people also take this chance to add spray foam around the windows to make sure there’s a tight seal with the frame.