Window Treatment to Block Sun

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One of the easiest ways to save energy by keeping the heat outside and cool air inside your home is to block or diminish the direct sunlight that shines through your windows. A substantial percentage of the heat gain inside a home in summer is directly attributable to windows. The good news is that there are several types of window treatments available that will help keep the sun out and reduce this unwanted heat in your home.


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Add Exterior Shades or Shutters

One option is to install exterior shades or functional shutters on your windows to stop the sun's heat before it ever reaches the glass. According to, exterior shades and shutters effectively decrease solar heat gain via windows.

Exterior shades, often made of vinyl, polyester, or fiberglass, are rolled up and down by hand or an interior crank. These work just like indoor roller shades and block your view when they're down all the way, although some are more opaque than others.


By contrast, exterior shutters can allow for a view when the slats are opened. There are two basic types of exterior shutters:

  1. Motorized or manually operated roller shutters consisting of aluminum or plastic slats that interlock to create a tight barrier against the sun when closed.
  2. Hinged wood or vinyl shutters that can be opened in winter to take advantage of solar heat gain or closed in summer to stop the sun's rays short of the window itself. Choose Bahama shutters, which are hinged at the top, or plantation/colonial shutters, which are hinged at the sides.


Install Awnings Over Windows

Installing awnings over windows on the south and west sides of your house is another solution. Awnings, which are tent-like structures made of a variety of natural and synthetic materials, add a stylish look to the exterior of many homes and allow light to enter the rooms while blocking the rays of the midday sun. notes that awnings can decrease solar heat gain during the hottest months by up to 65 and 77 percent, respectively, on windows facing south and west.

Apply Heat-Control Window Film

Applying heat-control window film to your windows is one of the most effective interior window treatments against solar heat and may work as well as external shades. Apply window film by sticking it directly to clean glass on the inside of your windows.


Window film is a permanent solution and shouldn't be taken down at the end of each summer. Some types of window film can even help your home to retain more heat in winter, which may cut your heating expenses. It's worth noting, however, that window film may hamper solar heat gain in winter. This can lead to higher heating bills if you live in a very cold climate with a paucity of sunny days during the colder months.

Use Interior Blinds or Curtains

Interior shades, blinds, and curtains also help to block out the effects of the sun. Hang curtains or shades with a white or light-colored lining or surface facing toward the window glass for an excellent barrier to solar heat. These window treatments may not work as well as external shades, but they can significantly reduce solar heat gain in your home during summer.


Plant Trees and Shrubs

Think ahead when you plan landscaping outside your windows. Trees, shrubs, and other plants that are sited appropriately and chosen for your soil type and climate will shade the windows during the most intense parts of summer.

Study the position of the sun during the hottest months when you want sunlight blocked from your windows and install plantings that will be in the sun's path. Or hire a landscape architect, who can suggest suitable types of plants and where to plant them. Using landscaping is an especially good idea if you'd rather allow some dappled light through your windows without the harsh rays.



Lee Morgan

Lee Morgan is a fiction writer and journalist. His writing has appeared for more than 15 years in many news publications including the "Tennesseean," the "Tampa Tribune," "West Hawaii Today," the "Honolulu Star Bulletin" and the "Dickson Herald," where he was sports editor. He holds a Bachelor of Science in mass communications from Middle Tennessee State University.