There are smart and inexpensive tricks to trapping heat indoors.
When the weather’s cold, ten times more heat escapes through standard windows than through insulated walls. That means your mid-year heating bill is vanishing through the glass.
But there are quick and simple fixes to help block the cold, says Amber Chamberlain from environmental consultancy Ecovantage. “Just covering up your windows in winter helps stop heat loss.”
When it’s cold outside, warm air turns into a chilly draught as it draws near exposed glass. To cut the heat flow, you need to trap a layer of still air next to the window pane.
“Curtains and blinds need to fit snugly and to be heavy – the heavier the better,” she says. “A good rule of thumb is that the more light coming through, the more heat that’s also being transferred.” Go for curtains that stretch below and beyond the sides of the frame, touching the wall or floor, and install pelmets (seals above the curtain or blind) to stop air at the top. You can fashion temporary pelmets from anything that fits – try cardboard or a thick scarf.
If heavy drapes aren’t to your taste, Ms Chamberlain suggests honeycomb or cellular blinds as a good alternative. “They trap a small amount of air within the blind itself, which acts as an insulating layer, and they still allow light into the home.” It’s wise to avoid gappy vertical and Venetian blinds.
Kirsten Johnstone, from Eco Edge Architecture + Interior Design, maintains that with careful thought, window coverings can be attractive as well as functional. If you’re building your home, she recommends designing window frames to fit recessed blinds. “You can create a channel that holds the sides of the blind within the frame,” Ms Johnstone says. “I think that’s a good solution, rather than the voluminous curtains that remind me of my Grandma’s house.”
She also says that, for homebuilders and retrofitters alike, pelmets need not be eyesores. “A minimal approach would be a small, painted box above the window or within a frame recess, painted out so it matches the wall. Try not to attract attention to it.”
Another way to improve your windows’ performance is by retrofitting double-glazing. Ecovantage suggests that DIYers try Clear Comfort, a membrane taped to the frame and made taut by shrinking with a hairdryer. “It’s virtually invisible and traps a layer of air in between the film and window, á la double-glazing,” Ms Chamberlain says. A 10-metre kit costs only $180.
For the less handy, companies such as Magnetite and MagicSeal sell secondary acrylic panes that attach to your window frame using magnets. “This solution is much more permanent and durable than DIY film. It’s more expensive, but still a fraction of [the cost of] double-glazing,” says Ms Chamberlain. The cheapest option of all is recycled bubble wrap, stuck on with the smooth side facing the room. “The little bubbles are perfect mini double-glazing cells, so why not use it on your windows?”
See related article: Windows