An extra window that works with the original
A storm window is a secondary glazed panel installed on the inside or outside of an existing window. Your original window stays in place. The added panel creates an insulating air space and, when fitted correctly, helps reduce air leakage. It is different from a replacement window, which replaces part or all of the primary window assembly.
Compare storm windows and replacementChoose which side of the opening to use
Exterior storm windows mount outside and add a protective layer in front of the primary window. Interior storm windows fit on the room side and can be useful when exterior access is difficult or the outside appearance must stay unchanged. Check mounting space, handles, blinds, and how you will remove or open the panel before choosing.
Shop interior storm windowsMatch the way your window opens
For a tall opening, compare vertical two-track and triple-track styles. For a wide opening that opens sideways, look at horizontal sliders. A fixed picture storm suits glass that does not need to open. Choose a configuration that preserves the access and ventilation you use.
Shop storm windows by type
Start with a sound opening
A storm panel does not repair rotten wood, broken primary glass, or a leaking wall. Address those problems first. Then measure at the actual mounting position using the guide for your window type. Opening measurements and finished frame dimensions are different; do not add your own allowance.
Find your measuring guideUnderstand the parts you are comparing
The primary window is the original assembly in the wall. The storm frame is the additional surround that holds its own glazing and, on some operating models, a screen. A sash is the framed panel that moves within an operating system. Knowing those differences helps you describe what needs replacing: a damaged screen is a different problem from a bent storm frame or a deteriorated primary window.
Compare window typesThink through daily use, not only winter
Before choosing a panel, picture how you use the opening throughout the year. Will you open it for airflow, reach the primary window to clean it, or remove a panel for storage? A fixed panel can suit an inaccessible operating requirement poorly even when its dimensions fit. For a bedroom or other escape opening, confirm that the additional panel preserves the required operation and access.
Explore ventilating optionsWhy homeowners add storm windows
The most common reasons are comfort and protection. A storm window cuts the drafts that move around an older sash, helps hold heat in during winter and conditioned air in during summer, and shelters the original window from rain, wind and debris. ENERGY STAR also notes that storm windows can inexpensively reduce outside noise.
Cost is the other reason. The U.S. Department of Energy describes low-e storm windows as costing about a quarter of what full window replacement costs, with similar energy savings. You keep the windows you already have.
See the energy numbersStorm windows for older and historic homes
Original wood windows are often worth keeping, but single-pane glass and loose sashes let heat and air escape. A storm window preserves the original sash, glass and trim while adding a modern layer in front of or behind them. Interior storms are a good fit when the outside appearance has to stay exactly as it is.
Storm windows for historic homesFrame materials you will see
Storm window frames are commonly aluminum or vinyl. Aluminum is strong and slim and comes in several frame colors. Vinyl is a common choice for interior storm windows. We offer exterior aluminum and vinyl storms, Low-E aluminum and vinyl interior storms, each made to order.
Shop by material and styleHow a storm window is installed
Most storm windows mount to the opening without disturbing the existing window. Exterior panels fasten to the outside frame following the product instructions, and interior panels hold in place by compression, tracks or turn buttons depending on the type. Many homeowners install their own, and others hire a contractor. Either way, an accurate measurement comes first.
Read the installation guide