Difference between New Construction and Replacement Windows

By: | Updated: May-28, 2019
The contents of the Difference.guru website, such as text, graphics, images, and other material contained on this site (“Content”) are for informational purposes only. The Content is not intended to be a substitute for professional medical or legal advice. Always seek the advice of your doctor with any questions you may have regarding your medical condition. Never disregard professional advice or delay in seeking it because of something you have read on this website!

It can be challenging to spot the difference between a new construction and a replacement window, especially since they function quite similarly. However, it is important for homeowners to distinguish between the two so they can make an informed decision before purchasing a window for their home. Read more to learn about these two options.

Summary Table

New Construction Window Replacement Window
Designed with a nail fin frame Not designed with a nail fin frame
Ideal for new homes or for newly-built home add-ons Ideal for replacing existing windows in a home
Not cost efficient when replacing old windows Cost efficient when replacing old windows
Involves a more invasive installation process Involves a less invasive installation process


new construction window
A new construction window

A new construction window, also called full-frame replacement window, is a type of window designed for a new home or a newly-constructed home extension.

replacement window
A replacement window

Meanwhile, a replacement window, also known as a retrofit window or insert replacement window, is built to replace existing home windows.

New Construction vs Replacement Windows

While they both play a critical role in ensuring proper ventilation within a home, there are major differences between new construction and replacement windows – not just in terms of design and application, but in the whole installation process as well.


Since a new construction window is designed for newly-constructed homes, it is built with a nail fin frame, which enables easy and fast window installation into the exterior framing of the house. A replacement window, by contrast, does not have a nail fin frame since it was designed to fit into an existing window frame.


As the names imply, a new construction window is intended for new homes or for newly-built home add-ons, while a replacement window is designed to replace existing windows in a home.

However, there is always an exemption to the rule. If, for instance, the window frames are already damaged, installing a new construction window is a better option since the window frames should also be replaced to ensure structural integrity.


The up-front cost of buying new construction and replacement windows greatly depend on the window’s size, style, and material. But when replacing old windows in an existing home, it is wiser to use a replacement window since it is cheaper and easier to install.

Plus, using a new construction window for an existing home can greatly impact installation costs since the exterior siding must be removed for the installation process.


Between these two options, installing replacement windows is less invasive since they do not require any structural changes prior to installation. The window is custom-made and measured to fit the existing frame and it is installed from inside the house.

New construction windows, on the other hand, need to be installed to complete the exterior of the home. They are directly nailed into the wall’s framing via the nail fin frame, and they involve a more extensive installation process, especially when used for replacing old windows with damaged frames.

(Visited 459 times, 1 visits today)
Did this article help you?
Thank you!
Thank you!
What was wrong?