Storm windows and weatherstripping: a cold-weather fix that keeps your windows
If your windows work but let in drafts and cold, adding a storm window and weatherstripping is a common repair-first answer, and it is easy to reverse.
What each upgrade does
Weatherstripping seals the moving gaps around the sash. A storm window adds a second pane of glass and a still air layer on the outside or inside of the existing window. Together they handle much of what homeowners are trying to fix, which is air leaks first and heat loss through the glass second.
- Weatherstripping closes the sash-to-frame gaps where most drafts enter.
- An exterior storm window protects the original wood from rain and sun.
- An interior storm window can be fitted where the exterior face must stay unchanged.
- Low-emissivity (low-e) glass in a storm window adds extra resistance to heat flow.
Choices you will face
| Type | Good for | Watch for |
|---|---|---|
| Exterior storm window | Protects wood, often removable in season | May be visible from the street; check historic rules |
| Interior storm window | Keeps the facade unchanged | Needs a tight seal at the interior trim |
| Weatherstripping only | Lowest cost, quick | Does little for the glass itself |
| Full replacement | New glass, new frame | Different appearance; see the replacement guides on the sister sites |
Local points for Philadelphia
- Facade visibility
- Exterior storm windows on a street-facing facade can fall under Philadelphia Historical Commission review for a property on the Philadelphia Register of Historic Places. An interior storm is a way to avoid changing the facade.
- Utilities and programs
- Ask your utility, PECO for electric service or Philadelphia Gas Works for gas, whether any energy efficiency programs are open to you; offers change. The Pennsylvania Weatherization Assistance Program serves income-eligible households through the state Department of Community and Economic Development.
- Older brick walls
- Rowhouse brick walls are thick and hold the cold. Sealing windows often makes a bigger comfort difference than homeowners expect.
Keep reading on this site
Sticking and painted-shut sash
Freeing sash, replacing sash cords and balances, and ending the rattle.
Rot, glass and glazing
What can be patched, what must be rebuilt, and how glass is reset.
Window repair in Society Hill and Old City
Historic townhouse sash, Commission review and lead-safe repair.
Window repair in South Philadelphia
Block-long brick rows, shared walls and old sash.
Questions people ask
Do storm windows work on single-pane wood windows?
Yes. Pairing a storm window with an old single-pane window is a long-standing way to reduce heat loss while keeping the original sash.
Will storm windows stop condensation?
They can reduce it on the inside glass, but they must be sealed correctly. A storm that traps humid air against the wood can make rot worse.
Can I install storm windows myself?
Some interior storm inserts are homeowner-friendly. Exterior units are often fitted by an installer, especially above the first floor.