Storm Window — What It Is, Where Used, and Replacement Guide

A storm window is a secondary window installed inside or outside an existing primary window to improve weather protection and energy performance.

What It Is

Storm windows add another air layer and barrier around an older primary window. They can reduce drafts, protect exterior wood sashes, and improve comfort without fully replacing the original window unit.

They are especially common on older homes where preserving historic windows is important.

Types

Common types include exterior triple-track storm windows, interior magnetic or compression storm panels, fixed seasonal storms, and custom low-profile storms for historic homes. Some include integrated screens for seasonal ventilation.

Where It Is Used

Storm windows are used on older wood double-hung windows, historic homes, seasonal cabins, and houses where full replacement windows are not desirable. They can be installed inside or outside depending on the product and preservation goals.

How to Identify One

Look for a second frame mounted over or inside the main window frame. Exterior triple-track units often show a separate aluminum frame with movable glass and screen panels.

Replacement

Replacement is needed when the storm frame warps, the tracks fail, the glass cracks, or air leakage around the frame becomes excessive. Many homeowners replace storms to improve comfort while keeping the original prime windows in place.