Connie Cao is a passionate gardener (who’s gained more than 10,000 Instagram followers for her inspiring gardening content) and has also studied permaculture design and a sustainable living diploma.

That’s why she and her husband have always taken a sustainable approach to improving their Melbourne home since purchasing it about six years ago.

‘Our gas hot water system broke down a couple of years ago, and the easy route would have been to replace it with a new gas hot water system on the same day,’ Connie says.

‘But I had always wanted to slowly get off gas for our home, so made us spend two weeks without hot water so that I could research the more efficient electric heat pump systems — during that time, we used a watering can and kettle for hot water!’

We joined energy advisor Tim Forcey for a comprehensive consultation of Connie’s house below, and there’s plenty of practical advice you can apply to your own home too.

Hot water system

Tim says Connie’s sacrifice of cold showers while finding the right electric heat pump hot water unit was worth it, noting that the Sanden brand she selected creates some of the most efficient units. ‘These types of hot water systems are five times more efficient than a gas hot water system — costing no more than one third of the cost of using gas.’

Connie says making the switch to the heat pump hasn’t impacted her electricity bill at all, and it’s significantly saved money on her gas bill.

Heating and cooling

Inspired by some of the information she’s learned from being in Tim’s Facebook group, Connie has also stopped using the home’s inefficient ducted gas heating and evaporative cooling systems. Instead, she’s installed four reverse-cycle air conditioning units: there’s now one in each of the two bedrooms, the dining room, and the home office.

Her experience with the units has been really positive, but the only issue is that the heat in the room sometimes feels ‘patchy’. Tim says this is likely a result of heat leaking out of the room, which can be improved by better insulating, better glazing, and draft proofing.

Draught proofing and insulation

One of the first things Connie and her husband noticed after moving into the home was how draughty it felt. It turns out there are a lot of gaps all around Connie’s house that are allowing the heat to escape, through the evaporative cooling vents in the ceiling; floor vents from the disused gas ducted heating; unnecessary wall vents; the single-glazed windows.

‘You can borrow a thermal imaging camera from the local library to check any cold spots in your walls, ceilings, and gaps in the insulation,’ Tim says.

He suggests decommissioning the ‘ancient’ gas heating and getting the evaporative cooling taken out, since the unit itself is taking up precious roof insulation space in the roof — which also needed a lot more insulation to improve heat retention. And simply getting a plasterer to come in and seal up these now unnecessary vents could cut Connie’s heating bill in half!

Solar

Connie’s home already has a solar system that helps reduce power usage in summer, but it’s almost 20 years old and only 1.5kW. ‘These days an average system is about 10kW,’ Tim adds.

Tim recommends replacing it with a new inverter and 10kW system, which would cost about $9000 for a mid-range system. Connie is also considering getting an electric car, so a large system like this would be essential down the track. ‘No one every expresses regret that their solar is too big’ Tim says! He recommends choosing the biggest solar system you can afford, because it’s not cost-effective to add more panels on later.

Tim recommends that Connie should start the solar process soon, and try getting it done before December if possible, because government solar rebates are programmed to reduce every year, and will eventually disappear all together.

Cooking

‘My goal for our home has always been to get off gas, and our gas stove is actually the last appliance on the list — the majority of our gas bill is simply the connection fee,’ Connie says.

Tim says there’s no downside to swapping the cooktop out for an induction stove, and disconnecting from gas will stop them paying ‘a dollar a day’ for something they aren’t using. Then the house will have successfully transitioned to being all-electric!

Overall assessment

Tim estimates that Connie’s house would be sitting at around three or four stars on the Residential Efficiency Scorecard. The average in Melbourne is about three stars, which translates to heating, cooling, and hot water bills of around $1700 a year.

But if Connie removes her gas connection, expands her solar PV system, improves the insulation and significantly draught proofs the home, the rating could increase to seven or eight stars — reducing her annual heating and cooling costs to just $250!

Next steps

Despite having already made strides towards a more energy-efficient home before her consult with Tim, Connie says she now feels confident sealing up the gaps in her home to ‘improve the thermal envelope of our house even further’.

‘In terms of larger scale projects, it’ll be researching a similar-sized induction replacement for our cooktop and officially getting off gas!’

Momentum Energy is 100% owned by Hydro Tasmania — Australia’s largest generator of renewable energy. Find out more about signing up to an energy retailer that supports the transition to renewables.

Find out more about engaging Tim Forcey for an energy audit for your own home here. Tim’s first book, My Efficient Electric Home Handbook is also coming out later this year and you can pre-order it online here.