Should I put in new windows?

[Daniel Paloscio]

I just bought my first duplex recently. A 3/1 2/1 block, built in '73. I'm going to live in the 3/1 for the next year or 2. Would it be a wise investment to buy new windows for the property? It has the old roll out windows but none are broken or malfunctioning. In the year I stay there I probably won't save the cost of the windows on the electric bill.

[Sam W.]

Daniel Paloscio

Replacing existing (old) windows that are in reasonable shape with newer "energy efficient" windows will not result in a marked reduction in energy bills. Here are data that I have heard:

"Old" windows probably have an R value of about R-1. The newest and most efficient replacement windows have a value of between R-2 and R-3...or 2 - 3 x as efficient as the older windows.

Most homes lose about 20% of their heat through the windows. Replacement windows that are R-2 or R-3 might lower that to 10% or 6%.

If your heating/cooling bill is normally $1200/year - then $240 of that ($1200 * 20%) is lost with old windows. New windows (R-3) could improve that loss to only $72 ($1200 * 6%) ..... a savings of $168 / year.

How many years will it take to "payoff" the new windows at $168/year?

Now...if you are replacing the windows because the new ones look better...that's another story. But don't replace serviceable windows seeking to save money on heating / cooling bills.