With rising energy costs, we are all very concerned with high heating and cooling bills. Much has been said/written about "energy efficient" replacement windows. You will hear and read advertisements about drastically reducing your heating bills. True, you will probably lower your heating bill somewhat, but at what cost?
A friend of mine just recently got a quote to have all the windows changed out in his vintage craftsman cottage at a cost of nearly $14,000, not including installation. He asked my opinion. I said that the time to recoup his cost of purchasing/installing his new replacement windows, as opposed to how much he would be saving on his energy bill, would probably be around 15 years. At that time, the thermopane glass seal would begin to fail and cloud up on the inside of the thermopane and would need to be replaced. The replacement cost of the glass units would probably be around $8000.00.
For those of you owning an older home with wood sash, think twice before replacing the windows. I have read many articles about the "pay back" of repayment windows, and it is very low. It does little to increase the value of your home, and can actually lower the value, if you have a vintage style home. My house was built in 1917, has original wood sash, double hung windows, which I have "tightened up" with proper weather stripping.
I have met a fellow who makes wood storm windows, with removable glass and screen inserts. These inserts are removed from the inside of the house, so the days of going up on a ladder trying to replace the wood storm windows are over. His wood storm windows are constructed using cypress, which does not rot unlike the new pine framed replacement windows, which can over time.
I am in the process of replacing my aluminum storm windows which I installed about 13 years ago with new wood storm windows. Aluminum conducts cold, where as wood does not. I truly believe my windows will be nearly as "tight" as new replacement windows, for a lot less money.
If you want to read more, check out "window shopping from Consumer Reports" October 2000, or Home Energy Magazine online. They state "the difference in annual savings between renovating old sash and replacing it with a new one was very small; retrofits saved only a few dollars".