Just when you thought working from home would save you time and money, the first winter bill arrives! COVID-19 restrictions are necessary, but they may leave us out in the cold! Now you’re spending more time at home you might realize you have a draughty house.
Isn’t winter romantic? Crisp mornings, hearty stews and hot chocolate. Mmm… But huddling around the heater shivering with your housemates – not so romantic! With winter on our doorstep, the last thing we want are our dollars leaking out through the cracks in our homes.
Talk to most renters, and you’ll hear some winter woes. Wearing coats indoors, gaps in floorboards, and draughts coming from…somewhere! We had a chat with Michael Ambrose, our Senior Experimental Scientist and former architect, about why some Australian homes are so cold.
“Some houses in Australia are designed to be leaky. In northern Australia, ‘troppo architecture’ houses are designed to be open to breezes, to keep the house cooler in summer,” Michael said. But unintentional draughts are an issue in southern Australia where they can add up to 20 per cent to your energy bill.
“Draughty house tends to go with age. The older the home, the leakier it is. Old weather board houses from the 1950s are very leaky, especially if they’re on stumps. You don’t get leakage through concrete slabs,” he said.
Michael, along with Mike Syme, former Senior Research Engineer, collaborated on one of the only studies on how airtight Australian homes are. The study found that Australian homes are ‘leaky’ by international standards and older buildings are generally much draughtier.
During the recent bushfires, Australians were encouraged to close their doors and windows to minimise exposure to fine smoke particles. But if it was a draughty house, smoke simply seeped in through the cracks and gaps.
In Australia, there is currently no specific level of air tightness for new homes to achieve. The building code states “sealing of the building envelope against air leakage” is required for compliance. But there is no measure as to what is an appropriate level of sealing.
Michael and Mike tested homes using a ‘blower door test’. The equipment sucks air into the house, before reversing it and blowing the air out. It calculates how many air changes per hour are occurring. Blower door tests find where there are gaps, where draughts form, where cold air can seep in and warm air can seep out. These gaps need to be sealed up.
Hot tips for a draught-proof house
Michael has some tips and tricks to make your home-office a little warmer this winter. These hacks can help you save your hard-earned cash.
Uncovered windows account for up to 40 per cent of heat loss in the winter.
Use heavy, lined curtains that fall below the window to keep warmth in
Check your windows for cracks
Consider sealing gaps with insulation strips or caulk (a waterproof filler)
Install pelmets above your windows/curtains to stop warm air escaping
You can also hang a heavy blanket or towel off the curtain rod.
Sealing gaps around doors can help draught proof your house.
If you feel a draught, make a ‘door snake’ for internal doors
For external doors, use a plastic or metal door seal with wipers
For draughts around the edges of the door, use adhesive weather stripping.
- Old heaters, fireplaces and hot water systems
Sometimes when services are removed the hole isn’t sealed. To draught proof the house you’ll need to seal it up.
Look for gaps around built-in appliances, at the back of cupboards and under the kitchen sink
You can fill gaps with expanding foam
If you have an old fireplace, use fireplace dampers to block airflow.
- Fixed vents and exhaust fans
Some old brick homes have fixed ceiling and wall vents. Block these to stop air leakage
For old exhaust fans, use a ventilation cover to block the vents over winter.
- Evaporative cooling units
These are meant to have winter covers or dampers but they’re not always effective.
You can draught-proof them by using magnetic strips around the vent receiver in your ceiling
Clip the covers on in winter and peel them off in summer.
- Other gaps
Listen for rattles or whistling and feel for moving air
Kitchen cabinets are often leaky, there may be gaps around the pipes and joints in the cabinets
Other areas include where skirting meets the wall, and where bricks meet the wood trim
Fill small gaps with silicone sealant
Fill bigger gaps with expanding spray foam
Be careful around internal gas appliances as they need fixed ventilation.
- Rugs and carpets
Cold air can roar up through gaps in the floorboards, especially in timber homes raised above the ground.
Use rugs and carpets to act as a layer of insulation.
- Let the sunshine in
There are things you can do if you have a draughty house. Keep your blinds or curtains open during the day to warm your home, especially north and west-facing rooms.
For more ideas, look to our tips on giving power bills the cold shoulder OR on the government’s heating and cooling site. Some states offer rebates for professionally installed draught-proofing. And if you’re a concession card holder you may get free materials. Visit the Australian Government’s Your Energy Savings website.
We hope you can keep a little warmer at home this winter.
(This is an edited version of a piece by Kate Cranney who is a scientist and Communications Advisor with the Land and Water, and Energy areas of CSIRO)