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Why most heating-savings advice gets it wrong
Two failures show up again and again. The first is jumping straight to "buy a more efficient heater" before squeezing the free wins, which is like upgrading the car before checking the tyres are flat. The second is the listicle: twenty tips of wildly different value lumped together, so a $5 draught strip sits next to "install double glazing" as if they're equal.
They almost never tell you which changes actually move the needle, or that the wins stack. Drop the thermostat, zone to one room and seal the draughts, and the savings multiply together into a much bigger number than any single tip suggests. The order matters: do the free, high-impact things first, then decide if you still need to spend.
How the savings actually work
Heating cost is driven by how hard and how long your system works to hold a temperature. Every free win attacks one of those.
The big levers, in order
Set point: each degree above 18 to 20°C adds roughly 5 to 10% to heating energy, so dialling back two or three degrees is a quick, painless cut. Zoning: heating one closed room instead of the whole house can roughly halve the cost. Draught-proofing: sealing gaps stops the warm air you paid for leaking out, so the heater cycles less. Timing: on a time-of-use tariff, warming up before the evening peak keeps heating out of the priciest hours.
They multiply, not just add
These don't simply add up, they compound. If zoning cuts the load by a third and a lower set point trims another fifth of what's left, the combined saving is bigger than either alone. That's why a handful of free habits, done together, can beat the gain from an expensive new appliance, and why the smart sequence is free wins first, purchase later.
Stack your savings: see the bill fall
Tick the changes you'll actually make and watch your winter heating bill drop. Because the wins compound, the order they're applied in is built into the maths. Every figure also appears in the worked example below.
Heating savings stacker
Tick the changes you'll make. Per winter.
Indicative reductions that compound (applied to what's left after each), not simple addition. The reverse-cycle switch is the one paid upgrade; the rest are free. Real savings vary with your home and habits.
Worked example. Starting from a $600 winter heating bill, the free wins alone:
| Change | Effect | Bill after |
|---|---|---|
| Starting point | — | $600 |
| Drop thermostat 2–3°C | −18% | $492 |
| Heat only occupied rooms | −35% | $320 |
| Seal draughts | −10% | $288 |
| Warm up before the peak | −10% | $259 |
From $600 to about $259, a saving of roughly $340 a winter, without buying anything. Add the reverse-cycle switch and the bill falls further again.
How Aussies overpay without realising it
A new heater in a draughty house heating empty rooms still wastes money. The free wins should come before any purchase.
A draught strip and double glazing are not the same size of win. Doing the high-impact, low-cost ones first is where the money is.
A house held at 24°C all evening burns far more than one at 19°C, for comfort most people wouldn't notice losing.
On time-of-use, the hours you most want heat are the dearest. Warming earlier shifts the load off the peak.
The insider insight: the free wins beat the dear upgrade
Here's the part the "upgrade your heater" advice misses. Because the free behaviour changes compound, their combined effect routinely rivals or beats swapping to a more efficient appliance, at zero cost. A household that zones to one room, drops the set point and seals the draughts can land close to a third or more off the bill before spending a dollar. The new heater would then save off a much smaller base.
That flips the usual order. The smart sequence is: do the free wins, see where the bill lands, then decide whether a paid upgrade still pays. Often the one upgrade still worth making is switching from a plug-in heater or gas to a reverse-cycle unit, but applied on top of an already-optimised home, not as a substitute for it. Spend last, not first.
What you should actually do
| Do this | Why it works |
|---|---|
| Set 18–20°C and leave it | Saves 5–10% per degree versus a high set point. |
| Heat the room you're in, shut the door | Can roughly halve the running cost versus the whole house. |
| Seal draughts around doors, windows, vents | Stops paid-for warmth leaking out, so the heater cycles less. |
| Warm up before the evening peak | Keeps heating out of the dearest time-of-use window. |
| Then, if needed, switch to reverse-cycle | The one paid upgrade worth it, applied on an already-tightened home. |
| In VIC, NSW, SA, QLD, ACT: compare plans against the DMO/VDO | A better rate lowers the cost of every remaining heating hour. |
In Western Australia (Synergy) and the Northern Territory (Power and Water) there's no retailer to switch to, so the free wins matter even more. See our home heating guide for the heat-source case.
Why this matters right now
With energy prices high and more homes on time-of-use tariffs, the free wins are worth more this winter than ever, because they cut load out of the dearest hours. Best of all, they're available to everyone, including renters and households in WA and the NT who can't switch retailers.
The takeaway: optimise before you buy. Stack the free changes first, and let any new heater save off a bill you've already shrunk.
Frequently asked questions
Current figures — last updated 2026-06-13
All values in AUD and Australian units. Indicative reductions vary by home and habits.
| Saving per degree on the thermostat | ~5–10% |
|---|---|
| Saving from heating one room vs the whole house | ~50% |
| Recommended set point | 18–20°C |
| Reverse-cycle vs plug-in/gas heating | ~60%+ cheaper to run |
| Typical combined free-win saving | ~⅓ or more off the heating bill |
| Reference price (NSW, SA, SE QLD / VIC) | AER DMO / ESC VDO [verify: current value] |
Sources: energy.gov.au, Australian Energy Regulator (DMO), ESC Victoria (VDO).