New Windows vs. New Window Treatments – Which Saves More Energy (and Money!)?

The answer may be new window treatments — if you choose the right ones.

Let’s look at the ‘R Values’ for cellular shades vs. single, double and triple paned windows. (The R Value is a measure of thermal resistance used in the construction industry.) Most older homes in Oakland have single-paned windows that allow excessive heat loss and gain.

Comparing R Values:

Here’s how the R Values for windows stack up:

Source: Colorado Energy.org

Here’s how a properly-installed cellular shade treatment compares when installed with single pane windows:

Source: Comfortex Shades: Testing conducted by the Tokyo Laboratory for Construction Materials.

Even the single-layer cellular shade with a single pane exceeds the R Value of the double pane window!

Symphony shade with side rails system has an R Value of 3.3!

The R Value of other window treatments varies depending on how they are fabricated and installed. But should cellular shades not suit your needs, many other types of treatments can also make a big difference in your energy bill.

According to research results posted at energysavers.gov, with the right treatments:

• Up to 33% of heat gain can be prevented in warm weather
• Up to 10% or 25% of heat loss can be prevented during cold spells

Source: Energy Savers.gov

Save Energy-Save Money-Save the Planet

In addition to saving money, energy efficient window treatments also help the environment. And there’s good news for those of you who are interested in the decorative aspect of window treatments — there are many more eco-friendly choices available now than were available just a year or so ago.

There are 3 factors to look at when considering which type of treatments will work best for you.

1. How well does the material work as a barrier to prevent hot and cold air infiltration into your home?Polyester fabric and cellular shade fabric (which is made of non-woven polyester) both insulate very well, as polyester doesn’t ‘breathe.’ Heavier cottons and linens rank next, followed by silks and then loosely woven fabrics.

   Drapes, roman shades and woven woods work well if fabricated with an insulating lining.

   

   Drape with a batting weight lining provides extra insulation

   Wood or vinyl blinds and shutters also provide good insulation if ‘S’ shaped slats are used. Most roller shades and pleated shades don’t provide much insulation; nor do metal blinds.

2. What kind of gap exists between the window trim and/or walls and the treatment?This is a key consideration. Although one type of material may inherently provide better insulation, the energy efficiency depends on how it’s fabricated to fit and how it’s mounted.

   Fabric treatments such as drapes & roman shades and cellular shades can provide more insulation than wood shutters — if you use an insulated lining and close the gaps. (For more on this, see the ‘Best’ section of chart that ranks energy efficient treatments at the end of the article.)

3. How well does the window treatment address aesthetic and practical needs?Not only can you increase your home’s energy efficiency by installing new window treatments instead of new windows, they also offer solutions for several other functional needs:

   Providing privacy and controlling glare — while still letting light into a room or blocking light. Some designs let you enjoy a nice view while simultaneously maintaining your privacy.

   Decorative value matters too. What look do you wish to achieve?

   Finally, a combination of ‘layers’ of treatments on a window may ultimately provide the best solution for your home’s windows.

DeAnna D’Zamba, of Custom Creations in Oakland, has over 20 years of experience designing custom window treatments. She can be reached at: Custom Creations Interiors.

Energy Efficient Window Treatments — From Best to Least Effective: