Energy Efficient Window Treatments

Whether you are looking to save money on your utility bills or are interested in going “green”, selecting energy efficient window treatments can help with both.

There are two major factors that make for an energy efficient window covering; the first is your Winter Insulating Value (R value) and the second is your Summer Solar Heat Gain Coefficient (SHGC).

Depending on the climate you live in, one component might be more valuable over the other, and if you live in a climate that is both hot in the summer and cold in the winter, we recommend a window treatment that offers both.  (Check out All Seasons for some multi-layer treatments that are perfect for homes that face every season. )

In San Diego, the most important factor for energy efficient window treatments is the ability to filter or block light, heat, and harmful UV rays. But for our friends in East County or in Sacramento, the ability to keep heat in during winter months is just as important.

Shading Co-Efficient

Let’s face it, if you have AC in your home, you know the minute your house gets warm the first thing you do is crank up the air conditioning. Doing this might be a wasted effort if your windows are acting as solar panels heating the inside of your home. Making sure your window coverings cast a shadow inside your home is like sitting under a shady tree as opposed to direct sunlight.

In the summer you are trying to keep heat it out, this measured by your shading co-efficient. Shading coefficient is what reduces the amount of light coming through the window. The highest rated shading coefficient window coverings include: drapery, cellular shades, room darkening  & blackout shades, woven wood and solar & roller shades.  If you have a great view that you would hate to cover-up, you can also use energy efficient window film to block a substantial amount of UV rays and solar heat while still giving you a view.

When thinking about a solar shades, another concept to consider for summertime window covering savings is taking into account the “openness factor”. We know we are throwing a lot of new terms at you, but we’ll try to explain it so you can be your own window covering expert. The openness factor breaks down how much visibility you have through your shade measured in percentages. So the higher the percentage the more visibility you have through your shade. When thinking of keeping your house cooler in the summer you would want a lower openness factor so less light comes through and the room stays cooler.

Winter R-Value

During the winter, it’s essential to retain heat in your home. Windows become cold and absorb the heat put off inside the home by humans, pets, and fireplaces. Although there might be a tight seal on the windows, there might feel like a cold draft is constantly coming in, causing homeowners to turn up the heat driving up energy costs. Having the right window treatments for wintertime savings will help create a buffer between the window and room, therefore retaining more of heat.

If your home is subject to more of the winter climate, it’s recommended to look for a window covering with High in R value. There are some products that are extremely high in R Value, these consist of drapery and honeycomb shades. Some other energy efficient window treatments with a good R value are shutters and blackout curtains – or any other type of window covering that completely blocks the window. The more air the window covering traps and the thicker the window covering the better insulator it will be.

What is R-Value

According to the department of energy, an insulating material’s resistance to conductive heat flow is measured or rated in terms of its thermal resistance or R-value — the higher the R-value, the greater the insulating effectiveness. The R-value depends on the type of insulation, its thickness, and its density. When calculating the R-value of a multilayered installation, add the R-values of the individual layers.

Instead of changing out your window coverings seasonally, you can look for an all purpose window covering that is energy efficient for all seasons. It’s recommended to go with a window covering that has a high R Value, which helps with keeping cold air out in the winter and cool air in during the winter. Another all purpose type of window covering is Low-E window film; which can be applied to the glass and then topped with another window covering for decoration, privacy, and light control.

As mentioned above, multi-layered treatments are absolutely perfect for all season homes and are our favorite type of energy efficient window treatments because they allow so much versatility. Start with a solar or roller shade, which helps with summertime energy savings, then layer with drapery or curtains with an R Value for wintertime savings, and end with a valance for decoration. So depending on the season you can use one or the other and still have a classic looking window covering that is stylish and appealing to you as homeowner.


There are many options in window coverings that can help with energy efficiency. There are both indoor and outdoor options. Indoor options such as cellular shades, blinds and layered draperies can reduce heat loss and gain. Outdoor options include reflective films and screens can help with summer heat gain.