How to Seal Drafty Windows Cheaply This Winter
Find whistling gaps first, then seal frames with rope caulk and film for a warmer, less drafty winter.
Seal drafty windows this winter by pressing removable rope caulk into small frame gaps and covering shut windows with clear interior shrink film. Save regular caulk for fixed cracks in frames and trim, and put weatherstripping, a flexible seal, on sashes and doors that must move. Rope caulk is a soft strip you press in by hand, while shrink film is clear plastic taped to trim and tightened with heat.
These low-cost fixes fit renters and owners who cannot replace windows this season. They matter most on single-pane or visibly leaky windows. Start with the largest whistling gaps, then treat comfort gains as the main win.
Verification note: Program terms and availability can change. This page was checked against linked sources on November 03, 2026.
Find the largest gaps first
Walk through your home before you buy anything. The U.S. National Park Service DIY audit guidance points to window frames, outlets, baseboards, door weatherstripping, attic hatches and dampers as common leak spots.
Focus money and time on the largest gaps. A whistling bedroom window wastes more comfort than a faint chill near an outlet. Sealing in order keeps cheap materials from going on spots that barely leak.
- Look closely at window frames and trim
- Feel outlets and baseboards on outside walls
- Check door weatherstripping, attic hatches and dampers
- Mark whistling gaps first
Match the seal to the spot
Use caulk only for stationary cracks between window frames, trim and siding. According to U.S. DOE Energy Saver via S.C.
Energy Saver, caulking guidance covers those fixed joints. Caulk would glue a moving sash or door shut. Put weatherstripping, a flexible gasket or strip, on operable sashes and doors.
The same DOE source explains in its weatherstripping guidance that these parts must still open. Check that the window still locks after you place it.
Use two cheap winter fixes
For winter, press removable rope caulk by hand into small gaps around drafty frames. The U.S. DOE Home Energy Checklist describes this as a cheap temporary seal.
Peel it out in spring so windows work again. For a window that stays closed all winter, tape clear interior shrink film tightly to the trim. ENERGY STAR lists Applying Plastic Over Windows as a DIY project in its assess-the-opportunity guide.
Shrink it with a hair dryer to form a still-air space that cuts drafts and condensation.
Know what window sealing can save
Reducing household drafts can save 5% to 30% of energy use per year. The U.S. National Park Service weatherization audit guidance ties that range to noticeably better comfort, mainly in leaky older homes.
Windows cause 25% to 30% of home heating and cooling energy use. U.S. DOE Energy Saver guidance points to single-pane or visibly leaky windows as the units where cheap interior sealing helps most.
EPA modeling cited by ENERGY STAR finds sealing plus insulation saves on average 15% on heating and cooling. The same seal-and-insulate savings analysis puts total-energy savings at 11%, or up to about 10% of annual bills. Treat cheap window kits as comfort fixes.
ENERGY STAR notes leaks around doors, windows and walls cause drafts but usually have less energy impact than hidden attic and basement leaks. Owners who can spend more can look at low-e storm panels, which DOE testing shows cut heating and cooling costs 12% to 33%, then peel out rope caulk in spring so windows open freely.