Inspect doors and windows for leaks and gaps

Leaks and gaps on doors and windows are the biggest sources of cold air getting inside your home. These also cause your heating to escape, thus wasting energy and money. To check for gaps, put your hand near openings to feel for drafts. You can also do the following:

  • Visual inspection – See if light seeps out of the edges of windows and doors. If you can see the light, then there’s a leak. Try to rattle them. Movement also means possible air leaks. Check weatherstripping or caulking around windows from the outside of your house. If they’re old and cracking, it’s time to fix or replace.
    • Do the candle or incense test – Turn off all fans, furnace or heaters and close windows and doors. Turn on your kitchen or bathroom exhaust vents. Hold a lit incense or candle close to the spaces around windows or doors. If you see smoke moving or swirling, then you have found a leak.
    • Leave it to professionals – If you suspect that there could be more sources of leaks in your house, e.g. electrical outlets, electrical and gas service entrances, attic hatches, cable TV or phone lines, etc. or insufficient insulation, call a licensed home inspector (accredited thermographer). Inform your landlord/building manager if you live in an apartment.

Repairing leaks can be as easy as re-caulking or weatherstripping windows and doors, or using pre-cut foam pads to seal gaps. Depending on the extent of the leak, use your judgement whether you can do the repairs yourself or if you need a professional.