If you’re considering storm windows vs replacement windows, you know there are many options. Both will increase the comfort and efficiency of your home or building. For replacement windows, there’s new construction and replication. For storm windows, there’s exterior and interior storm windows. Below we break down the comparisons between window inserts vs. full replacement. Cost, performance, ease of installation: we got you covered here.

View of entire home: learn if you should replace your windows or add storm windows to your existing.

When looking at storm windows or window inserts vs full replacement, you want an upgrade from what you already have. You want to reduce noise and drafts, increase energy savings and ease of care. You’ll also want to think about how it will affect the appearance of your home and whether you want to be able to open your windows. We’ll cover all of that in this comparison.


Storm Windows vs Replacement Windows: Construction

Both replacement windows and storm windows are available in a variety of construction types. This is a huge benefit for both, but it also means there’s an overwhelming amount of information to wade through. If you are deciding if you should replace your old storm windows or existing windows, we have an entire blog regarding construction of storm windows vs replacement windows.

Generally, replacement windows will be made of a glass that is either double- or triple-pane for insulation. Air or gas is injected between the panes for even more energy efficiency. The pane(s) are surrounded by a frame of aluminum, fiberglass, vinyl, or clad—interior of wood, exterior of one of the former.

Storm windows, both interior and exterior, are made of a glass or acrylic panel with a wood or metal frame. Storm windows are not an alternative to your windows, but are added to your existing windows and are attached to the window frame using screws, caulk, a track system, or a compression system. Some you will be able to open your window easily, some you need to remove the storm window to do so. If you have an historic home and/or window frames with old growth wood, you will want to add storm windows to your existing windows instead of undergoing full replacement projects.

Shot of windows and ladder: Learn how easy it is to replace and install storm windows.

Storm Windows vs Regular Windows: Performance

Any new window will perform better than an old window alone, especially if you are coming from a single pane to a double or triple. The performance of your replacement window is going to depend on the kind you get. For specifics and a breakdown of window types, visit our blog Performance of Storm Windows vs Regular Window.

Adding storm windows to existing windows can make them perform almost like new. And many storm windows offer DIY measurement, order, and installation processes. If you have particularly old windows, you may need to restore them before adding storm windows to see efficiency gains like new windows, but the investment is worth it. On average you are going to spend far less money and time to add storm windows to your existing windows than you will with a window replacement project.

Can storm windows block noise? Yes, storm windows can block up to 50% – 70% of outside noise and are much less expensive than soundproof replacement windows. The noise reduction of the storm window depends on its ability to air seal and the pane material and thickness.

There are many factors involved in choosing a window and a storm window, so using information from Energy Guide, Department of Energy, and PSU’s Green Lab, we’ve come up with some basics:

Performance by Category
indow window storm windows vs replacement windows


(Lower the U-Value, better the insulation)
Storm windows such as Indow inserts have U-Value of .54.
Replacement double-pane with ½” air space have U-Value of .48.
Replacement triple-pane glass, low-E on 2 panes, ½” paces with argon have U-Value of .23.
indow window storm windows vs replacement windows


Interior storm window inserts can reduce outside noise by 70% (18.9 dBA) when added to single-pane and 50% (10-12 dBA) when added to double-pane windows.
Replacement windows standardly reduce outside noise by approximately 25%. There are replacements optimized for sound control but they will be a speciality window higher in price.
indow window storm windows vs replacement windows

UV Blocking

Interior storm window inserts block 98% of damaging UV rays.
Single-pane windows let in 90% of UV radiation.
Standard double-pane windows let in over 80%.


Man installing replacement storm window

Window Inserts vs Full Replacement: Installation & Aesthetic

Replacement windows, once installed, will have a fresh, clean look. There’s no need for restoration or continued maintenance if you go with vinyl windows over wood. A variety of window shapes are available in replacement windows. Take a look below at how easy Indow inserts are installed in your window frames and how they don’t affect the aesthetic:


Original windows are part of a building’s original design. Replacement windows can seem out of place compared to the rest of the home’s aesthetic, even when a custom shape is applied. If you have an older home, board approval is often needed before removing any old windows. Not to mention, if you decide to replace the existing windows in your historic home instead of adding storm windows, you might be forced to address other necessary updates to your home. Replication windows can be made, but those are often costly and still may not meet historic board approval.

If you are placing storm windows in your home, you can maintain the original design intention. You can also choose just one or two problem windows to upgrade. With replacement windows, you would want to upgrade all windows at once to maintain a consistent look.


Video: How Do Storm Windows Work?


Attachments Energy Rating Council Certification

Indow is AERC certified. AERC, the Attachments Energy Rating Council, is an unaffiliated organization that rates window attachment products on energy efficiency by measuring various factors such as Air Leakage (AL) and U-Factor.

On air leakage, Indow scored in the top two out of 33 storm windows tested, 11 of which were interior storm windows. U-Factor is an indicator of heat transfer through a surface. It tells you how well a window product insulates. Indow inserts have a U-Factor of .3, making them a top performer on insulation among all available storm windows.



scott sidler installing hardware on energy efficient windows
“24.5 years. That is the average amount of time it will take you to recover the financial investment of a new window. And since the typical life span of a replacement window is only 10-20 years, that makes replacement windows a very bad investment.”

– Scott Sidler, The Craftsman Blog


Storm Windows Cost vs Replacement Windows

Simply put, interior storm window inserts are far less expensive than window replacement projects. Storm windows cost on average 75% less than wood and 50% less than vinyl. That’s fully installed and compared to a full replacement, not partial. According to Remodeling, 2021 cost for:

Vinyl window replacement is $19,385
Wood window replacement is $23,219
The equivalent job for Indow window inserts would cost $4,500.

The cost of wood and vinyl window replacements increases year to year by about $1,500-$2,000 with resale value from replacement remaining below the cost of replacement. Storm windows cost far less than replacement windows and there is no risk of harming your home’s historic value with replacement projects.

Vinyl replacement windows are the least expensive option, but they don’t last as long. And if one part breaks, the whole window has to be replaced again. Energy Star windows, which are on the higher end, are not as energy efficient as interior storm windows, so will not save as much money on bills.

woman installing interior storm window vs replacement window
Let Us Help You
bathroom window ideas for privacy


We value safety and privacy. We will never share, sell, or rent your data to third parties not directly related to your purchase or consideration of our products. Read our full policy here.