What is the Difference Between New Construction Windows and Replacement Windows?
When it comes to choosing windows for your home, there are two different categories to choose from: new construction or replacement. While the finished product serves the same purpose, the installation methods and available features will vary between the two. New Construction windows—as the name implies—are windows that are typically installed in houses that are being built. This is because around the frame of the window, there is a 1″ nailing flange (or nailing fin) that has installation holes cut out to accommodate installation screws. The window frame is set into the opening of the building envelope and the screws are installed through the installation holes and into the rough opening framing, after being shimmed accordingly. Appropriate flashing is then done over the nailing flange to create a strong seal to block out water and wind. Because of the nailing fin, new construction windows need to be installed prior to the building’s exterior siding being installed. That being said, new construction windows can be installed in replacement applications, where the siding is also being removed.
In contrast to new construction windows, replacement windows do not have a nailing flange around the frame’s perimeter. Therefore, these windows can be seated into the rough opening and installation screws can be installed through the frame. Since they do not have the nailing fin that affixes to the building’s exterior, exterior siding in most cases does not need to be removed. This allows for easy installation where homeowners only want their windows to be replaced.