My house is about 5 years old and our local building codes required a 5-star energy rating (Melbourne, Australia). This means there's solar hot water and both the walls and ceiling are insulated.

But it takes a lot of energy to heat the room, and as soon as you turn off the central heating (ceiling ducted) the house cools very quickly.

Somewhere, somehow, I'm losing way too much heat.

How do I work out where the heat is going? There's probably a lot of things I can do to save some of the heat, like installing double-glazing or even putting pelmets above the windows. But I would rather work out if the heat is going somewhere in particular that I can quickly and easily rectify.

Is there some gadget I can get to test something? Or some other method that's free/cheap?

3 Answers 3


Find an isulation installer that is a certified thermographer. An infrared scan of your home should reveal where the heat loss is occuring. The best time to do this is when the outside temp is lowest and your house is warmest. The problem could be missing or improperly installed insulation. Without a scan you are only quessing what the problem is. Ask about a repeat scan after any repairs to verify the problem has been resolved.


One quick & easy DIY trick is to light something that will smoke (like incense) and, when there is a strong temperature difference between inside and outside, walk around the inside of the house very slowly. Look for drafts that either pull or push the smoke. Common locations for leaks are around outlets, around plumbing where it comes through a wall, around windows & doors, the windows & doors themselves, along the eaves of the roof, at the openings for attics, and the house sills.

Also, if you have cobwebs, you have a draft. The webs tend to form in the area where the draft is strongest.

As for the sills - it was once assumed that the pressure on the sill from the weight of the house would be sufficient to seal any gaps between the sill and the top of the slab/foundation wall. This turns out to be incorrect. The sills are a common entryway for cold air, which is then pulled upward into the rest of the house by the "stack effect," caused by heated air rising.

Another possibility is leaky ducts in your heating system. There are several tapes commonly used for duct sealing that are entirely inadequate, so their glue breaks down in a relatively short time. Since your ducts come in via the ceiling, if they're leaky, then the hot air in the room could easily go right back out the way it came in, dissipating into the space above the ceiling via the duct joints.

Note: If you have ANY combustion appliances in your home (gas stove and/or oven, gas heater, oil furnace, woodstove, etc.) you should not start sealing leaks without getting an energy audit done. It is imperative that you ensure adequate, and appropriate ventilation in your home, lest you wind up giving your family carbon monoxide poisoning.

Good luck! Once the problem is solved, your family will be much more comfortable.

  • Even without combustion appliances, an energy audit is still the best way to go. Air sealing without proper ventilation can cause mold/moisture and other air quality problems if you aren't careful. Apr 16, 2013 at 21:33

I live in Queensland and I understand Melbourne winters. Check the silicon around window seals. My home used to whistle in winter with the wind.

Also check around the seals of your bathroom extraction fans.

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