Window replacement costs in Memphis

A Memphis window has two jobs. It has to keep summer sun out, and on the roughly 44 nights a year when the airport drops to freezing or below, it has to keep heat in.

The NFRC label on a new window puts a number on each job. U-factor tracks the heat that leaks out through the window. Solar heat gain coefficient tracks how much of the sun's heat it lets in.

Don't lean on the state code to pick for you. Tennessee adopted the 2018 International Energy Conservation Code for homes, effective July 2020, but with state amendments. The U.S. Department of Energy's analysis rates the amended version as equivalent to the 2009 edition. So the code's bar here sits lower than the edition's name suggests.

That matters most on older houses. About 43 percent of homes in the metro were built before 1980; close to one in five predate 1960. If your windows are the originals on a house that age, they went in decades before either of those code editions existed.