In an economical project years ago we installed exterior aluminum storm windows with their single pane glass on the inside of historic windows. We used black painted frames to not detract from the beauty of the old windows.
It worked for less energy loss....why not the screens? They could be full screens or 1/2 depending on your windows.
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Nelson B. Nave AIA
Owner
Nelson Breech Nave, AIA Architect
Kalamazoo MI
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