Fixing Drafty Windows and Doors Cheaply
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Before buying a heater, stop the cold air coming in. Ready.gov's winter advice starts with preparing your home with insulation, caulking, and weather stripping. Most draft fixes are cheap, renter-friendly, and take an afternoon. This guide covers the common ones; we haven't measured savings, so we don't promise a specific number.
Step 1: Find the drafts
- Feel for it: on a cold, windy day, slowly move the back of your hand around window and door edges.
- Watch for movement: hold a lightweight ribbon or tissue near edges and watch for flutter.
- Look for light: at night, with a light on inside, look from outside (or the reverse during the day) for light around frames.
- Common spots: where the window sash meets the frame, the bottom of doors, around window trim, electrical outlets on outside walls, and attic hatches.
Step 2: Match the fix to the leak
| Where it leaks | Cheap fix | Renter-friendly? |
|---|---|---|
| Gap where window sashes meet or slide | Rope caulk or removable caulk | Yes |
| Gaps where moving parts close (sash, door) | Self-adhesive foam or V-strip weatherstripping | Usually |
| Whole window is cold / single pane | Plastic window insulation film kit | Yes |
| Under an exterior door | Door sweep or draft stopper | Draft stopper: yes |
| Around the door frame | Weatherstripping | Usually |
| Gaps between trim and wall (non-moving) | Caulk | Ask your landlord |
| Outlets and switches on exterior walls | Foam outlet gaskets | Usually |
| Window at night | Heavy or thermal curtains | Yes |
Window film kits → Amazon · Rope caulk → Amazon · Foam weatherstripping → Amazon · Door draft stoppers → Amazon · Door sweeps → Amazon · Outlet gaskets → Amazon · Thermal curtains → Amazon
How to apply the common fixes
Window insulation film
- Clean and dry the window frame.
- Apply the kit's double-sided tape around the frame.
- Press the film onto the tape, leaving it a little loose.
- Use a hair dryer to shrink the film tight, following the kit's directions.
Weatherstripping
- Clean the surface; adhesive won't stick to dust.
- Measure and cut to length.
- Apply where the window or door closes against the frame, so it compresses when shut.
- Make sure the window or door still closes and latches.
Rope caulk
Press it into gaps by hand. It peels off in spring. Good for renters and for windows you don't open in winter.
Door sweeps and draft stoppers
A sweep attaches to the bottom of the door; a draft stopper (a fabric "snake") lies against the gap. The stopper is fully renter-friendly.
Free and nearly free fixes
From the National Weather Service's advice for when the heat goes out, and useful any winter night:
- Close blinds or curtains to keep in heat.
- Stuff towels or rags in cracks under doors.
- Close off unneeded rooms.
Also: - Open curtains on sunny windows during the day, and close them at night. - Move furniture away from drafty windows.
Don't seal what needs air
- Don't block vents for fuel-burning appliances like furnaces, water heaters, and fireplaces. Blocked venting can cause carbon monoxide problems. The CPSC notes CO poisoning can occur when venting systems are blocked.
- Keep working CO alarms on every level of the home and outside sleeping areas (CPSC).
- Don't caulk window weep holes (small drainage openings at the bottom of some window frames).
When to call a pro
Persistent condensation, rotted frames, broken seals in double-pane windows, or major gaps may need repair or replacement. Some utilities and states offer home energy assessments; check with yours. Ready.gov notes help is available through the Low Income Home Energy Assistance Program (LIHEAP) for people who can't afford heating costs or weatherization.
Then decide if you still need a heater
Once drafts are sealed, a room may feel comfortable at a lower setting. If not, see the space heater buying guide and run the numbers in the calculator.
FAQ
What's the cheapest way to stop a window draft?
Find the leak first. Then, depending on where it is: removable caulk or rope caulk for gaps around the sash, weatherstripping where moving parts meet, plastic window insulation film over the whole window, or heavy curtains at night.
How do I stop a draft under a door?
A door sweep or a draft stopper. In an emergency, the National Weather Service suggests stuffing towels or rags in cracks under doors when the heat goes out.
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