When to Use Replacement vs. New Construction Windows

When installing windows, you’ll be faced with the choice between new construction and replacement windows. While each option has its advantages and disadvantages, it’s crucial that you understand the differences so you can make an informed decision for your project. Selecting the right window is essential to your project’s success. Read on to learn these two installation methods' differences, benefits and drawbacks.

New construction windows are primarily made for newly built homes or other fresh spaces, such as commercial buildings, a home addition or a total remodel. In other words, they’re designed to be installed in a space that doesn’t have exterior cladding such as brick, siding, stucco or trim. That’s because these windows include a full window frame plus nail fins around the perimeter, which allow the product to be secured directly to the exposed surface of the wall. New construction windows can be utilized for replacement applications when portions of the exterior cladding or trim are removed to expose the wall surfaces.

If you’re noticing signs that an existing window needs changed but you’re not removing the exterior cladding (i.e. siding, brick, stucco, etc.) or trim, replacement windows are the way to go. Within the replacement window category, there are full frame replacement windows and pocket replacement windows. Full frame window replacement involves removing the existing frame and sashes and installing a new window that has an attached frame. Full frame replacement windows look very similar to new construction windows except they don’t have nail fins around the frame. If your original window frame is still in good shape, you can leave it in place and do a pocket replacement. This is a window unit that fits right into the existing window frame without nail fins.

Deciding between new construction and replacement windows depends on your project’s unique needs and circumstances. Use our simplified decision tree below to identify if your project requires new construction windows, pocket replacement windows or full frame replacement windows.

Besides the differences in the window units themselves, there are several other differentiating factors to consider when deciding between new construction and replacement windows:

New construction windows are installed during a project's initial building phase or require an existing window frame, siding and trim be completely removed. Given the additional work that siding and trim removal may introduce, new construction windows are typically more complex and time consuming to install than replacement windows.

Replacement windows can be installed into existing window frames, meaning homeowners can upgrade their windows without undergoing major construction work. Windows can be quickly and easily replaced by an installation professional. The window replacement process doesn’t require additional framing or trim work so is typically less disruptive to daily life.

While the price of the product itself is similar between new construction and replacement windows, the labor costs vary. Installing replacement windows usually doesn’t require as much work, so it can save you time and money compared to new construction windows. This is just one of the many benefits of replacement windows. New construction windows, however, are more invasive in terms of installation. There are normally more time and labor costs associated with this type of job since exterior siding or trim needs to be removed before the windows can be installed.

A clear advantage of new construction windows is the design flexibility they offer. By starting from scratch or removing an existing window frame, exterior cladding and trim, you have the ability to customize the window. A new construction window can be the exact shape and size you like.

If your existing window frame is in good condition, pocket replacement windows are compatible. This means you cannot change the shape or size. However, it does allow you to maintain the original look and feel of your windows while upgrading energy efficiency and durability.

In terms of the product itself, both new construction and replacement windows are extremely energy efficient. However, proper installation is key to capitalizing on efficiency. Since new construction windows are installed by attaching nail fins directly to the studs of a wall, they offer a tight seal that reduces energy loss. If you are replacing a window and leaving the frame in place, remember that the new window can only be as efficient as the existing frame. For instance, if there is air escaping around the frame, this can only be fixed by replacing the entire window, not just the sash.

While new construction windows are typically more customizable, they are usually more expensive and invasive to install. On the other hand, replacement windows are generally more affordable and compatible with existing frames but limited in design flexibility. Both products themselves are similarly energy efficient. What differentiates the two products is the installation method of each. New construction and full frame replacement windows can attach directly to the surface of a wall, offering energy efficient installation practices. A pocket replacement window is installed into an existing frame, meaning the new product is only as efficient as the installation of the existing frame. When making your choice, consider your budget, timeframe, design preferences and energy efficiency goals.

Need help figuring out which option is best for you? Reach out to a Pella expert in your area who can help determine the right fit for your project.