“Fogged” windows, or windows with condensation between glass panes, are commonly discovered at home inspections.  From my perspective, it’s a cosmetic issue because the condensation between panes isn’t a water intrusion issue for the home’s health itself.  Sure, you’ll lose some thermal efficiency when the window panes lose their seals, but it’s somewhat negligible in the grand scheme of things.  In my experience, Realtors are about 50% successful in negotiating replacement of “fogged” windows in real estate transactions. The Seller typically takes the stance that the “fogged” windows were obvious when the offer was made.  The Buyer, on the other hand, may take the position that (a) they didn’t notice the “fogged” windows or (b) they had no idea what it would cost to replace.  If you have a significant number of fogged windows, replacement adds up quickly. Standard “fogged” windows typically cost $300-$500 each to replace; contractors can usually pop-out the old glass pane and install a new one, without having to encumber trim and siding elements.  These pictures were taken at a recent home inspection on Orcas Island in the San Juan Islands.