• Window treatments help improve energy efficiency by providing an additional layer of insulation between warmed indoor air and cold window panes. (University of Missouri, October 1993)
• When closed, certain window treatments can improve the energy efficiency of a bare, double glazed window by almost 50%.(CBS Early Show) 

But which window coverings are best suited for the job? 

“The type of window treatment you use to cover your window has a lot to do with how effective it is at preventing heat loss,” said Tracy Christman the director of Budget Blinds Vendor Alliance.  “Window treatments with a higher R-value are better at keeping your home warmer during winter.”  

R-values are assigned to materials based on how well they insulate.  Materials with higher R-values are better at insulating than those with low R-values. We know that a bare, double-glazed pane of glass has an R-value of around 3.5.  Depending upon the window covering you layer over it, you can almost double the R-value!  Below is a list of the types of window coverings available and their approximate R-values when added to a bare, double-glazed window to help guide your choice:

PRODUCT / R-Value

Cellular Shades / 5.8

Shutters / 4.9

Roman Shades / 4.5

Woven Woods / 4.3

Wood blinds / 3.9

Faux Wood blinds / 3.9

Aluminum blinds / 3.8