How to find draughts
- Hold a lit incense stick near doors and windows and watch which way the smoke moves.
- Listen for rattling or whistling on windy days, and watch for moving curtains.
- Feel for breezes around skirting boards, floorboards and power points on outside walls.
- For a full picture, an assessor can do an air-leakage test on the house.
How to fix them
| Gap | Fix |
|---|---|
| Bottom of doors | Draught stoppers, door snakes or fitted door seals |
| Window frames | Foam strips and sealant around frames and architraves |
| Skirting boards and floorboards | Sealant, expanding foam or gap filler |
| Exhaust fans | Backflow-preventing covers on fans that vent into the roof |
| Evaporative cooler vents | Vent covers in the months you are heating |
| Unused fireplaces | Seal or close off the chimney if the fireplace is not used |
Keep the air you need
Rooms with gas heaters, gas cooktops or other fuel-burning appliances need ventilation. Do not seal fixed vents or flues; ask a licensed gasfitter if you are unsure. See gas safety.
What it is worth
Heating and cooling are 20% to 50% of home energy use, depending on the climate. Cutting heat loss by 15% to 25% through sealing makes a real dent in the biggest part of most winter bills, for the cost of a few rolls of foam strip and some sealant. Combine it with insulation and better window coverings.
Common questions
Sealing gaps may reduce heat loss by 15% to 25%, according to CSIRO research quoted by energy.gov.au. The dollar saving depends on how much you heat and cool.
Hold a lit incense stick near doors and windows and watch the smoke. Rattles, whistles and moving curtains on windy days are other signs.
Homes need some ventilation, especially where gas appliances are used. Never seal fixed vents or flues, and air rooms regularly to manage moisture.
Sources
Every rate on this page comes from the regulator or the regulated retailer. Last checked October 2026. Prices include GST unless we say otherwise.