How to stay warm in a climate emergency

Find out the 8 factors to heating your home with low emissions.

Greenhouse Programs Officer, Brett Hedger offers sustainability advice and support to businesses, residents and community groups in Port Phillip.

He worked with Albert Park Kindergarten to achieve the status of Australia’s first carbon neutral kindergarten.

I’m working from home today in a 1950s weatherboard rental house where my thermometer says it’s 10.8 degrees inside and 10.6 degrees outside. My family calls this ‘indoor camping’ because the temperature outside is about the same as it is inside. We have experienced five or six winters with either no or very minimal heating.

Why do we do this, you might ask? The primary reason is to reduce our use of fossil fuels. We have one gas heater in our lounge area and not even the pilot light is running.

Brett Hedger at home

The second reason is to see what is possible and what it is like to live by our own words and to see how far we would go in a climate emergency.

I’m not suggesting that we all need to live without heating, but I am suggesting we need to live without fossil fuels. Regardless of your situation, I’d like to explain the key factors in relation to efficient low emission heating.

Here is my 8-factor formula to get the best out of your heating system regardless of whether you are in a residential or business setting, owning or renting. Changing any of these factors in a positive way will improve the efficiency of your heating system and reduce your environmental impact. The easiest way to get started is by using this simple formula.

Environmental impact of winter heating = Heating system X fuel used X delivery system X personal behaviour X size of space X retention system X thermostat setting X activity level.

1.   Heating system – what kind of heating system do you have?

You may be familiar with ducted heating, reverse cycle air conditioning, hydronic and portable heating. Like me, you might be stuck with what is in your rental house, or it might be too expensive for you to change the system to something more efficient. In my case, we have six main rooms and only the lounge room has a heating system. But there is no point heating the lounge room if I’m working on my computer in the bedroom, so we leave it off. For my situation, the installation of high efficiency reverse cycle air conditioners would make sense.

2.   Fuel used – what type of fuel does your heating system use?

Basically, you have two choices, gas or electricity. Some people might think burning wood is efficient, but it isn’t in most cases and causes a significant amount of urban pollution and other problems out in the forests and elsewhere. I’m going to rule out wood because of all the complexity and problems involved in sorting it out, it just isn’t worth it. That leaves us with gas and electricity. Gas is problematic because it has no option for being renewable or zero emissions, it’s just a bad old fossil fuel. I have a gas heater, and this is the reason I don’t use it. The best fuel source for heating is electricity. Accordingly, if you’re going to use electricity, best to make it renewable. I’ve been using GreenPower at my various houses for around 20 years and you can too with a simple call to your electricity retailer.

3.   Delivery system – how does the heat get from the heating system to the place where you want it?

Not all heating systems have a delivery system. My own gas heater burns gas and then gets an internal fan to push it out into the room. Other systems you might have include gas ducted and other whole house heating systems. The heat is forced down a series of pipes or ducts to the rooms where the heating is required. Just like a hose, if the ducting or pipework has leaks and is not insulated, you will lose heat either under your house or in the ceiling. The bottom line is that it is worth maintaining your delivery system and keeping it in good order, well insulated and free from leaks.

4.   Personal behaviour – do you dress adequately and keep doors and windows closed?

I arrived at a friend’s house recently on a very cold day and was greeted at the front door by my friend who was in a T-shirt. As I glanced around the house I noted that the entire house was being heated, for this one person, in the middle of winter, to walk around in light pants and a T-shirt. It is worth having a think about what you do in your own house and match this with what you are trying to achieve in the larger environment.

5.   Size of space – how big is the space you want to heat?

This is one of the key elements of the whole equation. What exactly is the volume of air that you are trying to heat? My own lounge room is 3.4m by 4.3m by 3.1m giving it a total air volume of 45.3m3. Compare this to trying to heat a whole house (10m by 20m by 2.4m) with a volume of 480 m3, or over 10 times bigger than my lounge room. Size does matter when it comes to heating. It’s always best to keep a small cosy high-use space heated and everywhere else unheated.

6.   Retention system – can the heat be retained in your space?

How well does your space retain the heat you put in it? If your house or building is like most that I visit, then you’ve got problems. The common problems fall into three categories, gaps, holes and insulation. I think most of us now understand the need for good insulation, at the very least in our ceilings. It also makes sense to insulate your walls and your sub-floor. However, it is important to realise that good insulation does not fix gaps and holes. Gaps are those things that shouldn’t exist but do and are commonly found around windows, doors and skirting boards. Holes, on the other hand are those things that could easily be closed but aren’t. A good example of a hole is a door. When it is closed, it makes a nice barrier to retain heat. When it is open, everything on the other side of the door needs to be heated as well. Standard windows offer little protection to the outside world and need to be covered with well-sealed appropriate furnishings. It may surprise you, or it may not, but finding outside doors and windows open in homes and offices is a common source of excessive bills. I’m sure you’ll be familiar with a local café that has either its door open or has outdoor heating. These places have no retention system whatsoever and are in fact trying to heat the entire troposphere, which is quite difficult to do.

7.   Thermostat setting – how hot do you want your house to be?

I’ve been in houses during mid-winter sweating in near 30-degree temperatures, while talking to people about reducing their energy bills. And then I wander toward the patio to find an open door because they like fresh air or because the dog needs to get in and out. These types of situations are excessively wasteful. Setting thermostats somewhere in the range of 18-20 degrees celsius is a good setting for winter heat. Anything above this means extra energy and extra environmental footprint. You will find that this setting is ample when balanced with the other factors above.

8.   Activity level – how active are you during the winter months?

At my house, when we are not under our doonas, we like to keep active. We also mimic our reptile friends once the sun is out and take time out to just soak up the warmth of the sun.Sitting still for long periods won’t help stave off the cold. The best cure is to do some exercise, physical work, to get outside for a bit and get our bodies moving.


In summary, heating systems can be improved by taking a systems approach to these 8 key factors. Paying attention to all of them, even in small ways, will have a multiplier effect in terms of keeping you warm, lowering your winter heating bills and reducing your emissions.

Here are some resources where you can get more detailed information in relation to winter heating: