Stop the sun from passing through your windows and keep the heat out in summer.
Windows can let a lot of heat into your home in summer, especially if you have large unshaded west, east or north-facing windows. It’s better to stop the sun's heat from hitting the glass than to have to deal with the problem once the heat has already entered your home. The best way to shade your windows depends on which way they face, because as the sun moves through the sky, its height and angle changes.
How to shade north-facing windows
Fixed horizontal shading devices, such as eaves and pergolas, are ideal for shading north-facing windows. If they are well designed, they can stop the high summer sun from hitting the glass, while still allowing the low-level winter sun to shine in and heat your home in winter. Some pergolas have louvres that can be adjusted to provide complete shading in summer, while still allowing the sun access in winter.
Adjustable external shading, such as blinds, awnings, roller-shutters and conventional shutters, are also suitable for shading north-facing windows in summer. The thicker and more opaque the material, the better the shading effect will be. The external shading should be adjustable to allow the sun in during the winter months and on cooler summer days.
How to shade east- and west-facing windows
During summer, east-facing windows can be a major source of heat gain in the morning, while west-facing windows can be a major source of heat gain in the afternoon. Adjustable external shading devices (such as blinds, awnings, louvres or shutters, or angled metal slats) provide the flexibility to block the low-angled morning and afternoon sun.
While eaves, pergolas and even verandas provide some benefit, they are not very effective at shading east and west windows as they do not block out the lower-angled early morning and late afternoon sun in summer.
Adjustable shading devices allow greater flexibility to make adjustments on a day-to-day or even hour-by-hour basis, in response to changing weather conditions and comfort levels.
If you have a veranda it may be possible to install blinds on the perimeter to shade the windows, walls and veranda itself, making the whole area more comfortable in summer.
Windows that face north-east and north-west are also best shaded by adjustable vertical shading devices such as awnings or blinds.
South-facing windows receive almost no direct sunlight, so don't require shading in summer. However, the cooling breezes in summer usually come from the south so they are useful for cross ventilation. South-facing windows will lose heat from the house in winter unless well protected with either double glazing or heavy curtains or pelmets.
Find out more about energy efficient windows with our other how-to guides.