As a Melbourne-based home comfort and energy advisor, I’ve been in thousands of homes. With each home I visit, there is usually something new for me to see and learn.

Here is one thing I’ve learned. There are some very important matters that folks often do not know about their homes.

Why the ignorance or lack of knowledge? It may be because we weren’t “taught these things in school”. Or because each Australian home can be so different, and so when people move from one home to another, or indeed move from another country to Australia, they encounter things they’ve never seen before. 

Or it may be that we are all quite busy and specialised. Who changes their own oil in their car these days? So perhaps also when it comes to home inspection and maintenance, in the back of our mind we think it must be someone else’s job. But who is that person? If only we could drive our house down to the maintenance shop so someone else could look under the bonnet!

Whatever the reasons, here are seven key things I see again and again that people do not know about their homes.

1: Turn on your air con for the cheapest heating 

At the University of Melbourne in 2015, we worked out that people can heat their homes with their reverse-cycle air conditioners (aka air-source heat pumps) for as little as one-third the cost of burning gas, or one-fifth the cost of using a simple electric-resistive heater.

In Australia’s colder climates, and in times of increasing gas prices and pressures on your home budget, here is possibly the biggest consumer win ever!

But still, seven years after we published our research, I visit plenty of Victorian homes where people are yet to hear the news. I suggest we all tell our friends and family members to find the heat button on their reverse-cycle air cons and start saving.

Also, please note the same “reverse-cycle” heat pump technology is used in “hot water heat pumps” to heat your water for far less than burning gas.

These heat pump technologies, along with the induction cooktop, are allowing people to set up their new homes to be gas free, or to shift their existing homes totally off gas. Say goodbye to the gas grid.

2: Clean the air filter in your heating/cooling system 

Occasionally however, I encounter a client who has heard about heating with the air con and did give it a try, but unfortunately was unsatisfied with the result. “My air con doesn’t seem to do the job for heating,” they say. To which I always ask, is the filter clean? And I often get the response: “What filter?”

Just like your car, any home heating/cooling systems that move air (including gas-fired heating systems) will have or should have air filters. Would you never have your car’s air filter cleaned? Find out where your air filters are located and give them a clean. This can be done DIY (do it yourself). You may be amazed at the impact.

3: How does my centrally-ducted heating system work? 

Too often my clients do not understand how “central” or “ducted” heating/cooling systems work. Since air is invisible, many people have not twigged to the idea that in a central heating system, the heated air that enters a bedroom needs to find its way back to the “return air register” (or “return”) which often is located in a central hallway or stairwell. In other words, a centrally-ducted heating/cooling system should be a closed-loop recycling system.

If your home has a centrally-ducted system, there should be nothing obstructing the air that needs to flow from bedrooms and other rooms back to the “return”. In other words, doors need to be left open (or else have a very large gap at the bottom of the door) to allow the system to function. 

Therefore with “central” heating/cooling systems, it means you will most often be heating or cooling the entire house. Opportunities for operating different house “zones” will be limited. This shortcoming can be a reason to not have a centrally-ducted heating system and rather to opt for “not-ducted” or individual room-by-room heating/cooling equipment, such as individual “split system” air cons. I explain the various heating/cooling combinations and possibilities further in a webinar here.

Just passing through

In homes that easily leak air to the outside world, closing doors and therefore choking off your heating system converts it from “closed-loop” to “once-through”, meaning you get one shot to use the valuable heat before it leaks out of the house through gaps around windows in an isolated bedroom, for example. Meanwhile, at the other end of the system, the “return” is now starved of returning air and instead will draw cold air from outside via that big gap under your front door.

For these and other reasons, I see householders with ducted-gas heating systems spending up to $20/day burning gas, while in our home, we are comfortable and heat with two “split-system” air cons for less than $150/year, or less than what other homes may spend over eight cold days.

Something that contributes to householder confusion is the presence in many Victorian homes of evaporative cooling systems. These are indeed “once-through” cooling systems and are operated differently to “closed-loop” heating systems.

4: Up in your roof space – your insulation isn’t where you think it is

Most (but not all) Victorian homes have insulation in the roofspace. But often it’s not where the householder thinks it is.

For roof space insulation to be effective, coverage needs to be 100 per cent complete. There must be no bare plaster exposed in your roof space, neither on horizontal ceiling surfaces, nor on vertical “knee-walls”. Bare plaster provides very little insulation so any uninsulated surfaces show up with a thermal-imaging camera as patches on your ceiling or bulkheads that are either very hot (in summer) or very cold (in winter). With no insulation in summer, each of these patches acts as a radiant heater on your ceiling beaming down on your sweaty head. And in winter, heat rises to escape straight through your ceiling.

Unfortunately insulation coverage is often far from 100 per cent perfect for a few reasons. The horrible legacy of the dangerous halogen downlights means in some homes there were dozens of holes left through the insulation in order to minimise house fires. Even when the lights are upgraded to LEDs, seldom is the insulation rectified. And even worse, anytime someone goes into the roofspace to change a light fitting, install the NBN, hunt for a water leak, or run electrical cables for a new solar PV system, insulation is shifted out of the way and not put back.

Corrupted roof space insulation is having a major impact on our home comfort and on heating and cooling bills.

5: Get rid of your gas meter ASAP, before the gas industry gets even more upset

Many Australian homes are moving their space heating, water heating, and cooking away from gas. And then the only things left to do are to stop receiving a gas bill and to have the gas meter hauled away. We are finding around Australia that the charges applied for this process of gas meter “abolishment” range from $69 to $1500 depending on which company is your gas distributor and their views on making householders pay one final big gas bill.

I don’t know if or when state and territory regulators will establish a fair price for gas meter abolishment, but there is a case for readers to act quick before the gas industry gets even more upset about customers leaving their grasp.

6: Our homes are draughty – but life doesn’t have to be like this 

Air is invisible. Therefore during windy winter days and nights, all the air streaming into and out of our homes often goes unnoticed, except that we feel cold and our heating bills skyrocket. 

Generally my number one home improvement suggestion for clients relates to draught-proofing. Whether it is unused but unsealed chimneys, evaporative cooling vents not being seasonally closed up for winter, legacy wall vents, gaps under and around doors or windows, gaps hiding around the architraves or skirting boards, it all adds up to massive uncontrolled air leakage. 

Under windy conditions, and under “blower-door” leak testing, poor-performing homes might experience up to 60 “air changes per hour” (ACH), meaning nearly every minute all the warm air is being blown out of the house. Again, an example of a “once-through” heating situation!

Whereas after basic draught-proofing, some of which can be DIY and may even be done unobtrusively by renters, that air change figure might be reduced to a reasonable figure of just 6 ACH, meaning a factor of ten improvement in air leakage. This is some of the lowest hanging fruit around when it comes to reducing household bills and improving household environmental and climate restoration performance.

A caveat: as a householder reduces uncontrolled air leakage, ventilation must then be appropriately managed (such as by opening windows at certain times) to allow fresh air in and to purge household contaminants such as moisture, carbon dioxide, and a range of other pollutants including carbon monoxide or nitrous oxides which can be a feature of burning gas in or around the house. 

7: Don’t hang laundry around your living spaces to dry – and other critical moisture management tips 

One thing about homes with massive uncontrolled air leakage is that householders can seemingly get away with some very bad practices inside. One of these is failing to manage moisture.

Extraction fans should be diligently used to expel moisture from cooking or from bathrooms.

But another common source of moisture is wet laundry draped around living spaces to dry. Some people think this can be an environmentally friendly or “efficient” thing to do and saves running a very inefficient 1 or 2 star electric-resistive clothes dryer.

Fortunately these days very efficient heat-pump-condensing clothes dryers now exist that score energy ratings right up to 7 to 10 stars. These dryers condense all moisture (and re-use the recovered heat of water condensation) delivering the liquid water into a receptacle or putting it down a drain so that very little moisture is released into the living space.

Hanging clothing and bedding around a home to dry can release many litres of water into your home. I know this because of the many litres of water we collect in the receptacle of our heat pump condensing dryer. (Here is a link to the video.) 

I expect this practice of drying clothes around Australian homes dates back to a time when our homes were very leaky and warmed by a roaring open fireplace. This was also a time when heat-pump-condensing clothes dryers did not yet exist. As we tighten up our homes, we must control moisture and thankfully the heat-pump-condensing dryer is now available to efficiently dry laundry on days unsuitable for drying on the line outdoors.

Where to get more help: 

So where can people go to learn more about our homes? 

Right here of course, with many Fifth Estate articles covering these topics. Also, click on any of the links I have provided in this article.

For those on Facebook, the group I started “My Efficient Electric Home (MEEH)” provides an endless stream of discussion with members solving the mysteries of their households. 

Finally, a new website was recently launched by Geelong Sustainability that is receiving rave reviews as it tries to crack the tough nut of how to provide information on the thousands of different things that can go on, and can go wrong, in our homes.

Tim Forcey is an independent home comfort and energy advisor and researcher. Tim is also founder of the 60,000+ members Facebook group “My Efficient Electric Home (MEEH)” where people volunteer their time every day to help each other understand their homes.

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  1. Thanks for the heads-up! I just brought my laundry in, to dry inside. Since I was going to be warming the place up a bit, I set the washing rack under cover and ‘downwind’ of the aircon exhausts. Towels dry in a snap.

  2. Drying clothes in the room is common in UK and France. It certainly is not unique to Australia. In fact in many environments the extra moisture from the clothes makes up for the drying out effect of heating. In Switzerland where I lived for a few years a humidifier was needed to get a decent sleep and avoid headaches.

    A further comment. Heat pumps are expensive and most cannot afford the initial capital.

    1. agreed – we usually hang our washing-machine-spun-dried clothing on a drying rack inside our unit balcony door glass where it can get some sun during winter days

      and it’s typically dry by the next morning – in winter in the warm air-flow of our split reverse-cycle air-con, it can be dry within hours

      and with our average indoor humidity in Sydney of between 60-75% according to my room meter, there’s no risk of mould as we also have cross-flow ventilation with windows at north and south ends of our unit – the only time our indoor humidity rises over 80% is with days of rain like we had earlier in 2022 – quite unusual.

    2. Replying to Peter Cohen.
      What works overseas might not make sense in Australia.
      Yes, in UK and France and elsewhere where the heating is on 24/7 day and night non-stop for months… folks do things… that might not make sense in Australia… where it is rare to see the heat on 24/7 day and night non-stop for months.
      So yes this is an excellent example of how confusion in Australia… with so many folks aware of what goes on elsewhere… can reign!