A close-up image of a person installing an interior storm window.

Old, drafty, and single-pane windows are a major source of air leakage and heat loss in a home. But replacement windows are also a costly investment and not always a possibility.

Storm windows are a great solution for heat loss and soundproofing, which also work with existing windows. In addition, they can be installed by the homeowner, meaning you don’t have to hire an expensive team of professionals or wait for the installation team to fit you into their schedule. 

Whether you choose to install heavy-duty exterior storm windows or simple and more aesthetically-pleasing interior storm windows, you will see significant energy savings and create a more comfortable and healthy living environment.

What to Know Before Installing a Storm Window

A person is installing an exterior storm window on a brick house with a ladder leaning against the wall next to him.

There are a few things to consider when picking out the right storm window product for your home. It is best to understand what the purpose of the storm window is and what your end goals are before making your decision. 

You will also need to make decisions based on the type of storm windows you want, the materials, desired aesthetics, and how much effort you are willing to invest in the installation and upkeep.

Interior vs. Exterior

The first step is to determine whether you will be installing interior or exterior storm windows. Both will increase the comfortability of the home by reducing noise levels and drafts and help with energy efficiency. However, there are a few key differences between the two that are important to note.

Exterior storm windows attach to the outside of the window frame using caulk, screws, or hinges for a permanent or semi-permanent application. They require more tools and skills to install and can decrease the curb appeal of your home, but exterior storm windows offer extra protection from the elements to prevent further damage to existing windows. Most exterior storm windows come with weep holes to allow accumulated moisture to evaporate. These weep holes do make exterior storm windows less energy efficient.

Interior storm windows are more discreet and are easier to install and maintain from inside your home. Most interior storm windows are custom-made to fit your window snugly and create a near-airtight seal. They do not offer exterior protection to the window, but they do create a better seal for improved energy efficiency. Interior storm windows are also designed to easily pop out during the seasons in which they are not needed, but many find that the energy savings are worth keeping them in year-round. 

Storm Window Materials

A close-up image of a window insert with a brown frame to match the wood window frame.

Material choice for storm windows typically comes down to aesthetics and performance.

When it comes to frames, wood can be the most aesthetically-pleasing and desired material. However, wood frames tend to contract and expand with the changing weather, which can alter their effectiveness. Regular maintenance is required to keep them looking and performing as they should.

Aluminum or other metal frames are a durable and lightweight option. They also do not require as much maintenance and last for a long time. But they do insulate as well as alternatives.

Vinyl has become a popular choice for its low-maintenance and designability, considering the range of color options that are available. However, vinyl frames often become brittle and need to be replaced more often.

The panels of storm windows are usually either glass or acrylic. Glass is more common on exterior storm windows, and acrylic is more often seen on interior storm windows. Acrylic retains heat better than glass, so it is more energy-efficient. Acrylic is also very lightweight and has a higher visible light transmittance than glass.


To determine the size of the storm window and whether or not you will need custom sizing, you will first need to obtain the measurements of the existing windows. Make sure to carefully measure each window in order to get the dimensions right the first time.

Key Features

Some additional things to keep in mind are whether or not the windows will need additional weatherstripping, what tools and skills are required during the installation, and how easy the windows are to maintain once installed.

Some exterior storm windows may require weatherstripping to create an airtight seal. But not everyone wants permanent storm windows or windows that must remain closed all year long. Interior storm windows do not require caulk or weatherstripping, and they can be easily removed in the warmer months.

If you plan on installing the storm windows yourself, you will want to choose an option that doesn’t require ample time, skills, or effort. Some exterior storm windows require additional tools like ladders to reach the second story or caulk to create an airtight seal. Interior storm windows are considerably easier to install without the use of extensive tools or a team of professionals.

It is also important to consider how much effort you are willing to put into the upkeep. Choosing materials like aluminum or vinyl make it much easier to maintain compared to wood frames. Also, removable storm windows are easier to clean than permanently installed solutions.

Doing the research and making the right choice upfront will save you valuable time and money in the long run.

Installing Storm Windows

A person wearing a dress and sandals is installing an interior window insert.

If you are installing the storm windows yourself, it is important to make sure you choose a product that is easy to work with and familiarize yourself with the necessary steps prior to installation. Also, make sure you have all the tools you will need on hand before starting the installation process.

Installation of interior storm windows is rather simple — much easier than their exterior counterparts. Usually, they just need to be pressed into place on the interior side of the frame, and then they are good to go with no additional fasteners needed. 

Some interior storm windows may come with clips that need to be pressed in order for the storm window to fit securely in place.

Exterior storm windows are more difficult to install. To prep your home, clean the exterior around the existing window and scrape off any old or flaking paint. Then, caulk the top and sides of the storm window, leaving the bottom uncaulked for drainage purposes. Hold the storm window, ensure it is square and level, and then screw it into place. Finally, adjust the expander so the bottom sits tight against the windowsill.

Some exterior storm windows are magnetic, and their installation is a little bit different. Instead of screwing and adhering the whole window, metal strips are fixed around the exterior perimeter of the existing window. The windowpane is then held in place by a strong magnetic hold, creating a heavy-duty seal.

Even if you choose to not have exterior storm windows installed by a professional team, it is still best to have an extra set of hands to assist you.

How Indow Can Help

A close-up image of a white framed window insert.

Here at Indow, our window inserts are easy to install and are custom built to fit perfectly into your window. That means all you have to do to install them is press them into place in your window frame. In addition, our inserts don’t require any magnets or tracking to stay in place, creating a low-profile design that practically disappears after installation.

Our affordable selection of window inserts and interior storm windows fit the needs of every home. We help you achieve effective insulation, historic preservation, soundproofing, and UV light protection. If you ever have any questions about the installation process or about which inserts are best for your home, our experts are available to help. 

Check out our selection of window inserts and reach out today for a free estimate