North and west-facing windows receive the most direct sun in summer, so it’s important to address these first.
The heat comes from sunlight hitting the window, so by shading the window from the outside, you can prevent the heat from entering your home. External blinds, awnings and deciduous plants are effective ways to do this.
But if you prefer not to interrupt your views, window films are an excellent option. Summer only films can block up to 84% of the sun’s heat, while year-round films can block the sun’s heat by 50%.
There are also simple aluminium foil products that can be applied from the inside, to reflect the light off a window that might be too difficult to shade from the outside. This is a good option if you’re renting.