The right order to upgrade your home
Do things in the wrong order and you pay for a heater that is bigger than you need. Or you end up with damp windows you then have to fix. Here is the order we suggest, why each step sets up the next one, and what the rebates were worth when we last checked them.
The short answer
Seal the gaps and insulate first. Then sort out fresh air. Then hot water. Then heating and cooling. Then solar. A battery and an EV charger come last. Each step makes the next one smaller and cheaper. Do it backwards and you end up paying for gear that is too big, and wiping water off your windows.
If you’re mid quote
Ask whether your heat pump was sized before or after somebody looked at your insulation. If it was before, ask for a new size.
If you’re starting
Start with draught sealing and ceiling insulation, both in the same couple of weeks. It is the cheapest step and it changes everything that comes after.
If something just died
Fix that one thing now. Then come back to this order for the rest.
Why order matters at all
Each job changes the size of the next one.
A heat pump is sized to how much heat your house leaks. Seal the gaps and insulate the ceiling first, and your house leaks less. That means you need a smaller unit. It costs less to buy, and less to run for the next fifteen years. Do it the other way around and you have paid for power you do not need, and nobody gives that money back.
The same idea runs all the way down the list. Solar is sized to how much power you use. Swapping your hot water and heating over to electric changes how much you use. So quoting solar first is really just a guess. A battery is sized to the solar power you have left over. And sealing your house, which is the cheapest and best thing on the list, is exactly what causes the damp that fresh air fixes.
None of this is a secret. It is just that each trade quotes its own job, and no one job is responsible for the order. The plumber does not ask about your ceiling. The solar installer does not ask what you are planning to do with the gas heater. So the order falls to you, which is why this guide exists.
If you only do one thing
Get your ceiling insulation checked. In most Australian homes built before 2005 it has flattened, been walked on, or was never put in. It is the biggest reason your heating costs more than it should.
The order
Seven steps, and what each one sets up.
Seal the gaps
Block the draughts around doors, windows, exhaust fans, downlights and the chimney. In most houses it is a day of work or less. It is the one step that pays you back in months rather than years.
Why it comes here
Everything after this is sized to how much heat your house leaks. This is the cheapest way to leak less.
Who does it
A draught proofing specialist, who uses a smoke pencil to find the leaks.
Insulate the ceiling, then the floor
Do the ceiling first, because that is where most of your heat goes. Under the floor comes next if your house is up on stumps. Only do walls if they are already open for other work. Otherwise it costs a lot for what you get back.
Why it comes here
Sizing a heater before this is guessing at a number that is about to change.
Who does it
An insulation installer who will climb into the roof and send you photos of what is up there now.
Up to $1,500
VictoriaVictoria offers a ceiling insulation discount to all eligible homes under the Victorian Energy Upgrades program. That amount is for an average Melbourne home. In colder regional areas it is up to $2,100. Every state runs something different, so check yours.
Ventilate on purpose
Make sure your bathroom and kitchen fans really vent outside, not into the roof. Then have a plan for moving fresh air through the house in winter. In a well sealed home this is not optional. The section below explains why.
Why it comes here
Sealing your house is what causes the damp. This step fixes it.
Who does it
A ventilation installer, or the electrician fitting your fans, as long as they duct them properly.
Replace hot water with a heat pump
After heating, hot water is usually the biggest part of an all electric bill. It is also the easiest swap to plan while your old unit still works. That is how you avoid a rushed weekend replacement at whatever price is available.
Why it comes here
This changes how much power you use, so do it before anybody sizes your solar.
Who does it
A plumber who has fitted heat pumps before, sometimes with an electrician for the wiring.
Up to $1,960
VictoriaTwo Victorian programs stacked together for owner occupiers swapping a gas unit for a heat pump and choosing a locally made product. Replacing an old electric system instead, the ceiling is up to $2,030. Other states run their own schemes for different amounts.
Sort heating and cooling
Now your house leaks less heat, get your reverse cycle system sized for the house you have now, not the one you had before. Expect a smaller unit than an older quote assumed, and a smaller running cost with it.
Why it comes here
This is sized to steps one and two. Quote it earlier and you get a unit that is too big, and you pay for that twice.
Who does it
A split system or ducted installer who works out the heat needed room by room instead of guessing from floor area.
$5,530
VictoriaThe Victorian discount for swapping a ducted gas heater for a 22.4 kW reverse cycle system. It is the largest single job incentive we have found anywhere in the country.
Then add solar
Once your hot water and your heating are both electric, your power use is finally the thing solar has to cover. That is when somebody can quote you an honest system size.
Why it comes here
Solar is sized to what you use. Do it earlier and you are sizing for a house that is about to change.
Who does it
A solar installer, who should look at your switchboard before quoting anything.
Battery last, EV charging alongside it
A battery is sized to the solar power you do not use, so it has to come after solar. An EV charger can go in any time. Doing it with the battery saves paying an electrician to come back twice.
Why it comes here
This depends on how much solar you make and how much power you use at night. You will not know either until the steps above are done.
Who does it
A battery installer, or your solar installer if they do both jobs.
About 30% off
Australia wideA federal discount on home batteries. Your installer takes it off the price up front, so there is nothing to claim back later. The amount steps down every six months until 2030.
The mistake that costs most
Sealing your house is what causes the damp.
An old draughty house dries itself out through its own gaps. Seal those gaps and you keep the warmth in. You also keep in the water from showers, cooking and breathing. That water has to go somewhere. If nothing is moving fresh air through the house on purpose, it settles on the coldest surface it can find. First your windows, then inside your walls.
That is not a reason to skip sealing. It is the reason fresh air is step three and not the last step. Do them together and the problem never starts. Do them a year apart and you spend that year wiping windows.
When the order changes
Three homes where this list is wrong.
This order suits a typical detached house that somebody lives in and owns. It is not a rule, and there are homes where following it would cost you money.
If you are in an apartment, most of the list is not yours to change. You do not own the roof, the walls or usually the windows. Start with draught sealing your own front door, then look at hot water and cooking, which are normally inside your own boundary.
If you rent the place out, the order still holds but the payback does not. Insulation and hot water are what change a tenant’s bills. They are also what state rules ask for. So they come first, even though solar looks more exciting.
And if your house is heritage listed or has solid brick walls with no cavity, the insulation step gets harder and more expensive. Ceiling and floor still work normally. Walls often do not. Ask before you assume it is on the list at all.
What we couldn’t confirm
The numbers we left blank on purpose.
Some numbers get passed around in quotes and Facebook groups with no government page behind them. A few come from schemes that closed while the old amount stayed online. We would rather show you the gap than make something up.
A state top up on top of the federal battery discount
Several states run something. The amounts and the rules are different in each one and they move, so we only print the ones we have checked that month.
“Up to $5,000” for whole home electrification
This traces back to a trial program that has closed. The number still turns up in sales material.
Window replacement rebates
Some states help pay for glazing through bigger energy programs, but the amount is small next to the job. Our windows guide explains why it is not the reason to do it.
Quick answers
The questions people ask next.
What if something breaks before I get to its step?
Fix it, then come back to this order for the rest. A dead hot water unit cannot wait for insulation. Just do not let a rushed job turn into a new gas unit you will want to rip out in three years.
Can I do several steps at once?
Yes. Sealing, insulation and fresh air are best done together. What you should not do is size a heat pump, a heater or a solar system too early. The steps above change how big they need to be.
Does this order change if I am renting the place out?
The order still works. What changes is what you get back. Insulation and hot water usually matter most for a tenant’s bills and for the rules a rental has to meet.
How much of this needs an electrician?
Heat pumps, heating, solar, batteries and EV charging all involve electrical work. An older switchboard often needs updating before any of them. Ask about your switchboard early, because it is the cost that surprises people most.
Why is the rebate I was quoted different from yours?
Because schemes change, and some quotes still use old numbers. Every amount here shows the date we checked it and links to the government page. If your installer’s number is different, ask which page it comes from.
How long does the whole list take?
Most people do it over three to five years, one job at a time, usually when something breaks or when money allows. Doing it in order matters more than doing it quickly.
What to do this week
Three small things, and none of them cost money.
Tonight
On a windy evening, walk each room and feel for draughts with the back of your hand. Make a list on your phone as you go.
This week
Look in your roof, or ask somebody who can to send you a photo. Flattened or missing ceiling insulation is the most common thing we hear about.
Before any quote
Write down how old your switchboard and your hot water unit are. Both change what an installer will tell you, and both are easy to check.
When you’re ready for help
Find the right help for your next step.
Get a whole-home plan
A home energy assessor can look at your whole home, identify the biggest opportunities and help you work out what to tackle first to make it more comfortable, efficient and cheaper to run.
Find an assessor near youFind the right specialist
Once you know which upgrade you need, find a business that specialises in that type of work and services your area.
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