The wife and I are looking to buy a home. We found a nice property, and everything is just as we wanted, with exception to the windows. From what I can tell, the windows appear single pane (which is somewhat unusual given that the home was built in 1993), and they have the exposed spring channel balance along both sides of the window (for sliding them up/down). Given that we live in the Chicago area, I would prefer double pane windows, as they would better insulate air inside the home during summer and winter. Not only would the temperature be more stable inside, but we would save money on energy cost, and have less noise from the outside.
Is there anything I may be missing in determining if the windows are single vs. double pane? I look at the edge, and there is no second glass piece on any of the windows (our current windows are more modern, so I know how the double pane windows should look). Given that this home is close to the most we wish to spend on a purchase, I don't want to assume the ordeal and cost of replacing windows in a two-story home. If they are single pane windows, should I consider this a deal breaker?
One option, which I have not yet pursued as we have not yet made a formal bid, was to try and negotiate down the price of the home, and use the difference to replace windows (if they are single pane). I don't know how much the previous owner is willing to negotiate, as they are selling it for almost what they had purchased it earlier this year, and allegedly done some upgrades to the inside. It is, however, one option worth considering, if necessary.