Did you know that up to 40% of a home's unwanted heat comes in through the windows? Sure, most of us realize that keeping interior shades and curtains closed during the hottest part of the day will help keep a home cooler, but for many climates there's a more effective solution.
Exterior awnings and roof overhangs are great for shielding windows from high afternoon sun, but aren't as effective for windows that face east or west, where low sun can be an issue. While interior shades block about 20%-60% of solar gain for these areas, a better option is to block the sun before it comes through the window in the first place (which also helps to reduce A/C costs).
Exterior shades do just that, blocking a whopping 85% of solar gain from coming into your house. These type of roller shades are similar to interior versions, but are made of a weather-resistant fabric and are either operated by hand or motorized. Unlike opaque interior curtains, "solar shades" limit solar heat gain while maintaining a filtered view, ventilation, and privacy from the outside. Stylistically, these types of shades are a favorite of mine because they have a low-profile when not in use and can be a more modern alternative to other clunkier shading devices.
Read More: Exterior Window Attachments Fact Sheet from BuildingGreen
(Images: Hunter Douglas)