We had window companies look at replacing them, but no one was sure about how to rebuild these windows and have them function in the same way. The prices were incredibly high. We developed a plan to rebuild the windows ourselves. We had ASAP Custom Windows make the new wooden window sashes, then our guys carefully took apart the jambs piece by piece and milled new parts to the exact sizes of the old that would work with the antique hardware.
It was a very technical and complicated project that was great for the house. The sun porch is still bright and airy, the new bi-fold windows are solid with proper flashing, and they function better than ever!