The house came with pretty good thermo pane windows that are still doing a pretty good job of doing what they were designed to do which is all well and good. When I touch them they are warm which is a far cry from the old single pane windows I grew up with.
Someone suggested I put in replacement windows to save money on heating bills. I glanced at the prices, about $2000/hole. Times 11 is $22K which will buy an awful lot of natural gas.
If I could save an average of $10/month that would mean about $120/ year. Do the math. It's not worth it. 183 years is a long time to break even. $22,000/120=183.33
Then you have to look at the manufacturing process which used various things such as petroleum, possibly wood, silica and so on. Those windows take time, energy and so on and so forth.
When you look at the entire picture you're probably not doing the earth a favor. You're sure not doing your wallet a favor, either.
The whole thing reminds me of the woman that takes her bottles to the recycler in the next town every week. It's not very much glass, a small number of bottles and jars but it's off to the recyclers every single week. The gas, wear and tear on her car probably does more damage to the planet than the recycling saves. If she got a good sized bin and didn't take the glass to the recycler until the bin was full she's probably actually be doing some good.
