With global temperatures on the rise and Australia’s climate ranging from hot humid summers to warm winters, we all seek ways to stay cool.
They don’t call Australia the sunburnt country for no reason. We live in a land of soaring temperatures and happen to sit right beneath a hole in the ozone layer. All this makes for some very hot temperature. Properties in Australia have all been built to suit this warmer climate, but with advances in technology and design there are always new ways to keep cool.
There are a lot of strategies, which vary in cost and difficulty, that will help maximise your property’s ability to stay cool in the ever-increasing heat of summer. There are also some larger projects to consider when heat proofing your home.
- Passive design. This design principle focuses on maximising a property’s design according to the climate in order to maintain a comfortable temperature.
- Envelope design. This design principle maximises the interior climate of your home. It focuses on integrating the form and materials of the building to create a system that optimises comfort and energy savings.
- Thermal mass. This is a building material’s ability to store and absorb heat energy and then release it into an area.
- Windows and shading. Reviewing where your current windows and overhangs or shadings are located, as well as considering where to put any new ones, will contribute to the overall coolability of your home.
- Air movement and ventilation. Reviewing where the walls, doors, doorways and windows sit in relation to each other will ensure fuller airflow throughout the house and maximise the cooling effects of any cool air. Ventilation also contributes to airflow. If there is no roof ventilation, then there is nowhere for hot air to escape.
- Insulation. Making sure you have the best insulation for your climate will help you heat and cool your home without blowing your budget by overusing aircons or heaters.
- Roof space. Hot air rises, so it’s always best to make sure that when it does, it can escape out of your house.
What can you do when renovating to maximise the cool in your home?
There are a number of things you can do to maximise your home’s cooling effects. We have broken them down based on budget, standard or luxury renovations. There are some options that fall into each depending on how much you want to spend.
Budget renovations to keep your home cool
It may sound like a simple idea, but fans are an important part of staying cool. Buying a floor or pedestal fan is a great low-cost way to keep cool with the added bonus of portability.
With most of these personal-style fans costing from $10-$40, you can get one for each bedroom.
Portable air conditioning
Similar to a fan, you can move these from room to room. The only constraint is that you will need a window so you can push out the hot air through a duct. Although relatively cheap and easy to install, portable air conditioners are not very energy efficient and can also be quite loud. They can range from $200 - $500 depending on the brand, size and functions.
Replace your light bulbs
Not a lot of people realise that light bulbs create a lot of heat. Older style incandescent light bulbs give off approximately 90% of the energy they use as heat. For example, a 75-watt bulb will give off 68 watts as heat. A fluorescent bulb does better and only puts out 60% of the energy it uses as heat. A 70-watt fluorescent bulb produces only 45 watts of heat and spreads the heat out further so you don’t feel it as strongly. They are also more energy efficient. The other option on the market is a light-emitting diode (LED) bulb. This bulb produces the least amount of heat as long as it is installed correctly with the appropriate housing.
|Amount of energy used in heat||90%||None*||60%||4 times the heat of incandescent lights|
|Heat emitted in degrees||47.2||1.9||16.7||N/A|
The number one place where heat will seep into a house is through your windows. A quick update to your curtains or blinds can help reduce this.
You have a number of options if you are looking to install blinds or upgrade the blinds you already have in your home. You can get roller, Venetian, honeycomb or Roman blinds depending on your budget and the aesthetics you are looking for.
|Type of blind||Cost range|
|Blockout roller blinds (up to about 2.4m wide)||$60-$70|
|Sunscreen or light-filtering blinds (up to about 2.4m wide)||$75-$85|
|Honeycomb roller blinds (up to about 2.4m wide)||$75-$125 (for more efficient double cell blinds)|
|Bonded roller blinds (up to about 2.4m wide)||Over $300|
|Venetian blinds||$47 (slimline metal)-$135 (timber or designer)|
|Roman blinds - blockout||$160|
|Roman blinds - soft fabric||$300|
Curtains range from soft, lace-like curtains to heavy two-layer curtains that help keep the heat out of your home. The price range depends on whether you get ready-made or custom-made curtains as well as on the fabric and style you use.
A custom-made curtain will tend to cost more, unless you feel confident sewing it yourself. There are also additional costs, such as the header tap, hooks, lining and eyes that you will need to buy. Ready-made curtains can range from $40 up to and beyond $300 depending on the size and fabric, but they come ready to use and are easy to install.
Window film or window tinting is a thin layer of plastic overlay that you can apply to a window to decrease the effect of the sun. You can purchase pre-cut pieces or get a whole roll that you can cut yourself to suit your needs. A static cling film starts at about $40 per square metre and doesn’t require adhesives, so it may be easier if you are doing it yourself. Alternatively, films that require adhesives, which are trickier to apply and require particular tools, are a bit more expensive but still cost less than a full window replacement.
Many parts of your home can deteriorate over time that could end up causing the loss of cool air and the intake of warm air. Door and window frames, vents, skylights, exhaust fans, poorly fitted or shrunken floorboards and other ill-fitting or changed junctions are just some areas where air can creep in and out.
There is a simple and cheap do-it-yourself fix for any leaks you find around the house. You can pick up a tube of sealant and an applicator gun from your local Bunnings or other hardware store for about $10-$30 depending on the
type and amount you need.
Making sure any cracks or leaks are sealed will not only help you keep your home cool by preventing heat from coming in and any cool air from going out, it will also help with electricity consumption. Your heating and cooling appliances won’t need to work as hard if none of the air is escaping.
Small tweaks to your garden and outdoor area are also a cheap way to make an impact on the temperature of your home. Planting shade-producing plants outside windows that get direct or constant sunlight will help lower the amount of heat taken into a room.
Standard renovations to keep your home cool
If you have a bit more cash to spend, you can make some changes to your window dressings that will help keep your home cool. From outdoor awnings to shutters to double-glazed windows, there are a range of improvements you can make to your windows to cool your home.
Three main factors affect the cost of awnings: size, installation and motorisation. An awning approximately 1500mm with depths of under a metre can cost $300. A manual crank, straight drop awning will cost around $400, whereas a motorised version will add an additional $400 to the cost. The materials used can also increase the cost. Basic canvas costs less than an aluminium awning or an awning using fabric that protects from UV rays.
Internal shutters are the budget option for those looking to add shutters to their home. Typically, plantation shutters are used, but you could also opt for indoor roller shutters. For plantation shutters, the price changes based on the size of the windows and the materials used. Solid timber shutters are more expensive than PVC shutters.
|Type of shutter||Cost range|
|Timber (Paulowina timber) 900mm wide||$220-$550; 700mm-2,200mm high|
|PVC||From $125 and up depending on size|
|Aluminium 900mm wide||$230-$730; 700mm-2,200mm high|
You will also have to consider the cost of installation as plantation shutters are typically custom made and professionally installed.
Another option is to replace the glass you have in your windows with double-glazed glass. This has a dual effect of limiting the heat coming in during summer and keeping the warmth in during winter. Double-glazed glass typically costs $200 per square metre plus trade costs for installation.
If you have a bit more room in the budget, you could place ceiling fans in each room to increase air circulation.
There are a range of options and sizes, but they tend to range from $70 up to and above $500, not including installation costs. You will need to get a qualified electrician to install any fans. Installation costs will be about $100-$200 per fan plus a service fee of $70-$130 and an hourly rate of about $70-$95 depending on the size of the job.
Split system air conditioning
Split system air conditioning units are wall mounted units that also have an outdoor unit that is usually housed on the side of the house or on the ground outside. These units can usually only cool a single room, or a very small apartment, and can range in cost from $550 up to and above $1500 not including the installation costs. Installation costs range from $60-$110 per hour + GST depending on the size and difficulty of the job.
Ventilation and air flow
Adding ventilation fans in your roof will work to push excess hot air out. Another option is to install a whole-house fan in the roof near the centre of your home to take all the hot air and push it out through vents that you have added.
Adding doors to hallways and stairwells can also control where the air flows inside your house.
Adding additional insulation to your roof, wall or floor can help curb the escape of any cool air you want to keep in your home during summer. There is a variety of insulation available, so you should do your research. Different climates and different areas of the home require different insulation types. The cost of insulation depends on the type of insulation used. You can pay $40 for a roll of R2.0 batts that will cover 11 square metres, though for most climates it is recommended you choose R2.5 batts which will cost $65 for 7 square metres of coverage. You can also get spray insulation or reflective insulation.
It is best to get insulation professionally installed. Installers also buy insulation in bulk, so they save on the cost of insulation, which they can pass onto their customers.
As well as making changes indoors, you can also make small adjustments outside your home to help maximise the cooling effect. For instance, small adjustments to your outdoor landscaping can help direct the airflow to the doors and windows and allow for full airflow in the house.
Other options include placing pools of water, such as a bird bath, near your doors and windows. The resulting evaporation will help cool your house. Adding shade-producing trees or bushes at strategic points around your home will also help keep your home cool.
Luxury renovations to keep your home cool
Outdoor roller shutters
Adding outdoor roller shutters to your windows will help keep your house cool and has the added bonus of additional security. These are installed on the outside of your window, are typically made of aluminium or steel and create a complete sound, sun and UV blackout for your windows.
Costs vary depending on the size of the windows, the material you opt for and whether you opt for automatic, manual or battery-operated shutters.
|Type of shutter||Cost range|
If you want a little more durability, cyclone shutters cost up to $200 more than standard domestic shutters. Or if you want to forgo the need for an electrician, a battery-operated shutter is about $50 more than an electric one.
You can install the shutters yourself or you can hire a handyman to help with the install. If you are opting for electric shutters, you will need an electrician to help install the shutter.
Patio or pergola
Adding a patio or pergola to your home will not only block the sun and keep your indoors cool, it can also act as an additional outdoor room for the days when inside is just too much. There are a range of options you can choose from when thinking about adding a patio or pergola to your outdoor space.
|Pergola type||Typical quoted prices|
|Small colorbond pergola||$2,500|
|Flat roof pergola||$3,000|
|Pergola with sheeted roof||$6,000|
|Pergola for a balcony||$2,700|
Data from serviceseeking.com.au
Installation costs for these different pergolas range from $45 per hour up to around $60 per hour depending on how complicated the job is.
Ducted air conditioning
If you have more room in your budget and aren’t afraid to make some major changes to your home, then choosing ducted air conditioning can be a great option. These systems are more expensive to install and run than other air conditioning types and use more power than a split system air conditioner.
The cost of ducted air conditioning systems depends on the area you wish to cover. Basic systems that are suited for an apartment or small house cost around $6,000 with installation. For an average-sized single storey house, you will need to pay about $10,000-$12,000, and a more complicated 2-storey house will cost you $15,000 or more.
If you do opt for ducted air conditioning, there are some benefits. Most systems allow you to set up zones so you can cool a living zone during the day and cool a sleeping zone just before bed.
Adding a programmable thermostat will allow you to set appropriate temperatures. You will also have the option to choose times for the system to automatically switch on and off.
Ventilation and convective air movement
If you are making some major changes to your home, you could install additional doors or windows in areas that will allow for effective cross ventilation in your home. You could add a window in a wall that blocks the afternoon breeze, you could adjust the width of a door or you could add an internal window to get that airflow where you want it.
If you are redoing your whole outdoor area, you should consider how your design can help or hinder your home’s ability to cool. For instance, you could put mulch beds or other ground cover under windows to avoid reflections from the sun.
You should pay attention to the plants and trees you use and their placement. If your home gets a nice afternoon breeze, make sure your plants won’t block the breeze and will guide it to your home instead.
When thinking about a water feature, consider where to put it relative to your back door so you can use the evaporative cooling effects of water. If you have the budget and the room, you could add a pool to get the maximum evaporative cooling effect.
If you are planning for a larger, more in-depth renovation, you should consider the orientation of your home. If you want to maximise the sun in the winter but minimise it in summer, look at the position of your windows and overhangs. See how the sun sits in relation to your home to make sure you maximise natural cooling effects.
You can also consider what materials you use on your home. For instance, brick is more effective than weatherboard at soaking up the heat without letting it seep into your home. Make sure you use lighter colours on your outer surfaces to reflect the sun rather than soaking the heat in.
With a larger renovation, you can reconsider where your walls, doors and windows are to make sure you maximise the airflow through your home. You can also use materials around these areas to assist with cooling your home, such as ground cover under windows that soak up sun. You could also use pools or ponds outside a window to help with evaporative cooling.
Other tips to stay cool that don’t involve changing your home
If you don’t have the time or the budget to make any changes to your home, these hints will help you keep cool during the summer:
- Be strategic about the use of appliances, such as ovens, dishwashers and dryers, that produce heat. Use them at night when it's coolest.
- Open doors and windows in the morning and at night to take in the cooler air.
- Paint your roof and outdoor areas in lighter colours so they reflect heat.
- Soak your feet in a bucket of cool or cold water when you are sitting in one spot for a little while or just before you go to bed to cool your body.
- Freeze a wheat bag then put it on your head or around your neck to keep cool.
- Dry your clothes in front of your pedestal fan or hang a wet towel in front of one. It will push the moisture from the wet clothes into the air making it cooler.
- Put some ice in a tray in front of the fan for an extra cooling effect.
- Stay low when you can. Hot air rises, so if you have two storeys stay on the ground floor to stay cool.
Data and figures from hipages.com.au unless otherwise stated.