Cutting a Canberra winter heating bill
Heating is around 60% of what the average Canberra home spends on energy across a year. Draughts are where a surprising amount of it goes.
Heating is the bill.
For most Canberra households, space heating in winter accounts for more than half of an entire year's energy use — the ACT Government puts it at around 60% of the average home's annual energy costs. That concentration is useful: it means a small percentage improvement in how the house holds heat is worth more than a large improvement almost anywhere else.
Up to a quarter of the heat leaves through gaps.
Air leaks and draughts account for up to 25% of heat loss from a house, and cracks and gaps alone are commonly 10–15%. In a standard 1980s brick-veneer property — of which Canberra has a great many — draught infiltration can be 20–30% of total heating energy. Draught proofing is, in the ACT Government's words, one of the cheapest and easiest ways to improve the comfort of a home, and unlike most improvements you can do the bulk of it yourself in a weekend.
Find the draughts in your house
Walk around the house
Tick what you find, and get an order to work in
Your list, in order
Tick anything you recognise and it will appear here, biggest effect first.
No dollar figure, deliberately. Air leaks account for up to 25% of heat loss and draught infiltration for 20–30% of heating energy in an older brick veneer, but turning that into a saving for one particular house would mean inventing its bill.
Five things worth doing, in order
- Seal the obvious gaps firstUnder external doors, around window frames, and where pipes and cables pass through walls. Door snakes and self-adhesive foam tape cost very little and address the largest single category of loss.
- Deal with the chimney and the exhaust fansAn open, unused fireplace is a permanent hole in the ceiling; a chimney balloon or damper closes it. Unsealed bathroom and kitchen exhaust fans do the same thing on a smaller scale, and draught-stopping covers are inexpensive.
- Heat the rooms you are inClosing doors to unused rooms and zoning the heating is free and immediate. So is closing internal doors to halls and stairwells, which otherwise carry warm air away from where you are sitting.
- Set the thermostat and leave itEvery degree costs. Setting a reverse-cycle system to a steady, modest temperature is cheaper than pushing it high and turning it off, because the system runs most efficiently at a constant moderate output.
- Close curtains before darkWindows lose heat rapidly once the sun is off them. Drawing heavy curtains at dusk rather than at bedtime keeps several hours of heat inside, and a pelmet or a curtain that reaches the floor stops cold air sliding down the glass and across the room.
When the cheap fixes run out.
Draught proofing has a ceiling. Once the gaps are sealed, the remaining losses are through the building fabric itself — the ceiling first, then windows and walls. The ACT Government's guidance is that insulation can halve heating and cooling costs, which is why it is the next step rather than a bigger heater. If you hold a concession card, both the ActewAGL insulation offer and Home Energy Support may cover most of the cost.
Frequently asked questions
External doors. They are the largest single gap in most homes, the fix costs a few dollars, and you can feel the difference the same evening.
No, and it can be unsafe. Homes need ventilation, particularly where there are unflued gas appliances, and sealing a house tightly without providing controlled fresh air causes condensation and mould. Target uncontrolled draughts, not all air movement.
Yes, particularly on single glazing, which loses heat quickly once the sun is off it. The gain comes from stopping the convection loop — cold air falling down the glass and running across the floor — so a curtain that reaches the floor and a pelmet at the top matter more than the fabric's thickness.
Not usually, but the gap is smaller than people expect in a poorly sealed house, because it cools so fast. In a well-sealed, insulated home a steady moderate setting while you are there and a setback while you are out is the cheapest pattern.
Related guides
- Energy efficiencyTwo programs
Ceiling insulation upgrade
Eligible ActewAGL customers can get up to $2,000 off the installation price plus a $600 bill credit paid at $50 a quarter. A separate ACT rebate covers half the cost up to $2,500. Both are means-tested, and they ask for different things.
- Electrification and solarBiggest single saving
Heat pump hot water
Gas or electric storage costs a typical four-person household $800–$1,200 a year. A heat pump runs at $280–$400 on a flat tariff, less on off-peak, and $50–$100 if it is timed to run on rooftop solar.
- Rebates and bill savingsDeclining rebate
Solar and battery rebates
The Cheaper Home Batteries Program takes around 30% off a battery's upfront cost, at full value on the first 14kWh. The rate declines every six months from 1 May 2026, so when you install changes what it is worth.
