Retrofit Windows: Pros, Cons, and Types

Improve your windows without replacing them.

Fact checked by Jessica Wrubel

If your windows aren’t providing optimal insulation, retrofit windows can improve energy savings without the costly undertaking of replacement or new construction windows. Retrofit windows include ways to cut energy loss and save money without changing your existing windows. While it is true that ?replacement windows are, in many cases, the best way to slow energy loss, there are retrofit alternatives that cost less and offer nearly the same performance as new windows. Read on to learn about different modification options, the pros and cons of retrofit windows, and what to consider when choosing these alternative solutions instead of window replacement.

What Are Retrofit Windows?

Retrofit windows are modifications to existing windows that improve the windows' energy-saving capabilities. Retrofit window solutions can include modifications such as storm windows, interior window panels, and interior thermal blinds.

A report by The National Trust For Historic Preservation finds that "retrofit strategies come very close to the energy performance of high-performance replacement windows at a fraction of the cost."

This means that three retrofit window methods will save nearly the same amount of energy as entirely replacing the windows. Factoring in retrofit windows' low cost in relation to replacement windows' high cost, the scales begin to tip in the direction of window retrofitting.

Pros and Cons of Retrofit Windows

Installing new windows all throughout a house is an incredibly expensive proposition. Retrofits provide cost and energy savings when replacing windows is not a viable option. To reap the most in energy savings from retrofit windows, choose products that meet Energy Star and AERC (Attachment Energy Rating Council) energy-efficiency standards. To determine if modifications will be the best solution for improved window performance, here are some pros and cons of retrofitting windows:

Pros

• Low-e exterior storm windows are 1/3 the cost of window replacement.

• Low-e exterior storm windows and interior window panels can reduce drafts and seal in air loss, which can add up to 10% to 30% in energy savings.

• Interior insulating blinds increase energy savings by reducing drafts and helping control temperature indoors when it’s hot or cold outside.

• If you have an old or historical home, retrofit windows keep the frames intact, preserving the existing aesthetics.

• Low-e exterior storm windows protect the existing exterior frames.

• Retrofit windows are faster to install and may be done as a DIY project.

• Retrofit windows can be operable.

• Retrofit windows can reduce noise.

Cons

• Windows from older homes may not be in standard sizes and may be difficult to match when sizing storm windows or interior window panels.

• If interior storm windows are not airtight, condensation can occur.

• Interior window panels won’t protect windows from outside elements.

• Exterior storm windows can cover up existing windows’ aesthetics.

• Retrofit windows may not last as long as new windows.

• If window frames are in bad condition, retrofits won’t fix issues like lack of insulation, rotting, or moisture damage, which may worsen unless the windows are replaced. 
  

Types of Retrofit Windows

Exterior Storm Windows

Homeowners often install exterior storm windows with an eye toward saving energy and money, yet they find that their efforts count for little.

The problem is not so much the storm windows as the approach to purchasing and installing the storm windows.

Some homeowners may purchase poor-quality storm windows that permit air leakage. Or they may install them with little care. More than anything, relying on storm windows alone to fix bad windows is never a solution. Storm windows are a supplement to a home's windows but they will never approach the weathertight nature of true windows.

Complicating matters is the fact that many homeowners lack the skills or inclination to install storm windows where they are most needed: the upper floors.

The highest value storm window is a low-e single-clear operable exterior storm; aluminum triple-track frame. While better quality storm windows are available, this window provides the best value, when the cost is factored in.

Interior Window Panels (Inside Storm Windows)

Interior storm windows, sometimes called invisible storm windows, are installed parallel to your existing window and improve the thermal and air leakage performance of the window.

Interior storm windows are similar to shrink-fit window film insulation that attaches to window trim with double-sided tape. The difference, though, is that window film is flexible and temporary, while interior storm windows are solid acrylic and semi-permanent.

Interior storm windows attach via magnetic strips or compression gaskets and can remain in place for as long as the homeowner desires. By contrast, shrink-fit window film only lasts one season, if that.

Cellular Blinds (Interior Insulating Blinds)

Interior cellular blinds are made of lightweight fabric and open and close in an accordion fashion. When the blind is fully extended, a honeycomb-like structure forms a thermal shield between the cold window and the warm interior.

Some cellular blinds install at the top of the window frame, much like mini-blinds. Better cellular blinds run along weather-stripped edge tracks to keep the blinds in place and the cold out.

Equally effective are quilted window blinds. These are made of thick, quilted fabric that rolls up and down.

One obvious downside of using thermal blinds as your retrofit window solution is that they are not transparent. They can only be used at night or, if you wish, during the day (thus not allowing natural light into the house).

Yet as nights lengthen and days shorten throughout the winter, there are far more opportunities to pull down the blinds and push back the cold.

Tips

In the New York area, there are periods when the sun sets as early as 4:20 p.m. in December. In more northern-situated cities, the sun sets even earlier: 4:19 p.m. in Seattle.

When to Choose Retrofits

If your window frames are in good condition, retrofit windows can extend the life of your existing windows and increase energy savings at a fraction of the cost of replacement. But to maximize the most benefits, choose Energy Star and AERC-rated products.

Retrofit window modifications cannot solve issues resulting from damaged frames like leaking, moisture, rotting, and air loss. Windows that are broken, cracked, leaky, or fogged and can’t be fixed, should be replaced. 

Read the original article on The Spruce.