Replacement vs. New Construction Windows (2024 Guide)

By Jessica Wimmer Updated June 19, 2023

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You have two options when installing windows: replacement windows or new construction windows. Both options have benefits and drawbacks, but the choice between them is usually pretty clear-cut depending on your project.

In this article, we’ll compare replacement windows and new construction windows to give you a better idea of the best window type for your remodeling project. You can also check out our guide to replacement window costs to help plan your budget.



What Are Replacement Windows and New Construction Windows?

Put simply, new construction windows have additional parts that allow them to attach to a wall’s wooden frame. Replacement windows don’t have these parts because the frame is already in place.

New Construction Windows

New construction windows are meant to be installed in a house frame that doesn’t yet have siding or trim. That means the window unit contains a full window frame plus a nail fin flange, which is a thin strip of material around the window’s perimeter designed to secure the window to the wall. During window installation, these attachment fins are nailed directly to the exposed wall studs.

Replacement Windows

Replacement windows, also called retrofit windows, are installed in an existing window opening. The replacement must fit in the same space, so you need to match the old window’s size and shape exactly. You may require full-frame replacement, which involves replacing everything down to the interior and exterior trim. If the original frame is in good shape, you may only need an insert replacement, which keeps the existing trim and sill intact.

The best replacement windows for your project depend on the installation methods used. Here are a few types you’ll come across.



Differences Between Replacement Windows and New Construction Windows

Here’s how these window styles compare when it comes to various performance factors.

Comparison FactorNew Construction WindowsReplacement Windows


Frame with nail fin flange around perimeter

May or may not have frame, no nail fin flange

Installation process

Takes longer, more disruptive

Quicker, less disruptive


Slightly lower unit costs, higher labor costs

Slightly higher unit costs, lower labor costs


Available in most home improvement stores

More difficult to obtain, must be ordered from manufacturer


Actual installation is easier but associated tasks are harder

Less complex but requires precision

Energy efficiency

Allows for tighter weatherproof seal

More likely to spring air leaks if fit is poor


Allows you to change window size or shape

Requires you to fit existing window size and shape

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Benefits and Drawbacks of Replacement Windows

Pros The installation process is quicker and less disruptive since walls and siding remain intact. The overall costs are lower. You can improve your home’s energy efficiency at a better price point.
Cons You must match the original window’s size and shape. Poorly fitted replacement windows are more likely to be leaky and drafty. You can’t install replacement windows unless the existing frame is in good condition.



Benefits and Drawbacks of New Construction Windows

Pros You have more options for customization by changing the window opening. Installing new flange and siding makes for better weatherproofing and ensures energy efficiency. You can replace damaged frames and wall studs in the process.
Cons Unless you have a new home under construction, you must remove trim and siding all the way down to the studs. The materials are a little less expensive, but labor costs are much higher. Totally replacing an existing home’s windows with new construction windows is unfeasible based on disruption and cost.



When Should I Use New Construction Windows vs. Replacement Windows?

These windows’ uses are fairly clear cut: You’ll use new construction windows when building a new home and replacement windows when upgrading existing windows. However, if you’re completing an extensive home renovation—such as an addition or extreme wall repair—new construction windows might be the better option. If the wall is getting stripped down to the studs anyway, using new construction windows will give you more customization options and better weatherproofing and energy efficiency.



Cost of New Construction Windows vs. Replacement Windows

Material and size have the biggest impact on price for different window types. Installing standard-size windows costs less than installing custom ones. Aluminum and vinyl windows cost less than fiberglass or wood windows.

However, there is a significant price difference between new construction and replacement windows. New construction windows cost 10% to 15% less than a same-size window replacement, but labor costs are 50% to 100% more.* Thus, installing new construction windows is more expensive overall. There are plenty of affordable window replacement brands if you’re aiming to keep costs low.

*According to Angi.



Professional vs. DIY Window Installation

Because these two window types are normally installed for different reasons at different times, a do-it-yourself (DIY) approach can be complicated.

Professional Installation

Attaching a new construction window to your home’s studs is fairly simple. However, if your home has exposed studs, it usually means it’s either still under construction or undergoing a major renovation. In these circumstances, new construction windows are typically installed by professional contractors. 

A top-rated window installation company can also install replacement windows, since getting a good fit within the existing window frame can be difficult, especially in older homes where things have shifted or warped. You’ll pay for labor but gain peace of mind that the job was completed properly.

DIY Installation

Opinions differ on how easy it is to install replacement windows yourself. Popping your current windows out and setting new ones in is certainly less difficult than stripping your home’s exterior down to the studs. However, fitting a new window to an old frame, particularly if it’s in bad shape, is difficult and can require some complicated modifications. Consider DIY versus professional window repair costs, and be honest with yourself about how much time and effort you can devote to the project.



Our Recommendation

Most homeowners upgrading their windows should opt for replacement windows over new construction windows. New construction windows make the most sense if you’re building a new home or addition, unless you’re prepared to expose wall studs and replace siding, trim, and drywall. The best window brands typically have a variety of excellent replacement and retrofit windows to choose from. Take a look at your options and then start measuring for your new windows.

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Replacement Window vs. New Construction FAQ

Is it better to use replacement windows or new construction?

Unless you’re in the process of a serious remodeling project or your window frames are severely damaged, you’re better off using replacement windows. They’re far less disruptive to install, and labor costs will be much lower.

Can you use a replacement window as a new construction window?

You can use a replacement window instead of a new construction window if there’s already a window frame in place.

Is it worth replacing builder grade windows?

Builder-grade windows often use lower-quality materials, so they’re less durable and can leak. Replacing them with newer, energy-efficient windows can save you money on utility bills in the long run.

What is the difference between new construction and retrofit windows?

Retrofit windows can be installed in existing window frames without disturbing a home’s siding. New construction windows must be nailed directly to the house’s frame, so siding and trim must be removed first.

What is the difference between a replacement window and a new construction window?

New construction windows are surrounded by a nail fin flange that attaches to a wall’s wooden studs. Replacement windows don’t have this flange.



How We Chose the Top Window Brands

We researched and analyzed dozens of window manufacturers. We then crafted a rating system based on each brand’s standard and energy-efficient product offerings.

We spoke directly to representatives at each company to learn how the installation process works and determine how each brand personalizes its windows for each home. We also closely analyzed each company’s warranty options to ensure their product and labor guarantees match or exceed industry standards.

Finally, we assessed the manufacturer’s years of experience and customer reputation. In addition, we analyzed the 100 most recent Google Reviews for each provider across various locations and branches.