R-Values of Shutters: Comparing Energy Efficiency of Window Coverings

Kimball Jones

We talk a big talk when it comes to energy efficiency in window treatments. That’s because we have the hard data to back us up. With the help of some independent research, we’ve been able to directly compare the energy efficiency of the most often-chosen window coverings in Southern California, from blinds to drapes to shutters.

What’s An R-Value And Why Does It Matter For Window Coverings?

Everything in your house that separates indoors from outdoors, from the roof to your window coverings, has an R-value. That number tells you how good it is at blocking thermal energy from moving through it. A larger r-value means a more effective insulator.

honeycomb shades in Southern California space 

So what difference does the r-value of a window covering make? Well, a more effective insulator makes it easier to keep your home at your preferred temperature. Whether you want to keep the heat inside at wintertime or keep your home cool in summer, good insulation is crucial to that effort. That’s especially important for your windows, as they’re one of the biggest culprits in heat loss throughout your entire house.

Comparing R-values & Energy Efficiency Of Window Treatments

You don’t get the same benefits from every window treatment, at least not in terms of energy efficiency. Though there’s some difference based on the material and thickness between different vendors and makes, here’s what you can expect to find when comparing window treatments.

Window Treatment

Average R-Value

Window alone








Hardwood Shutters


Honeycomb shades


Polywood plantation shutters


R-values from Energy.gov and HouseLogic.

A short look at the table tells you a number of things. Perhaps the first thing you notice is that a few certain window treatments barely give you any benefit whatsoever (ahem, blinds), whereas others are insulating powerhouses. That big gap in R-value might make for a difference of several degrees – that’s the difference in whether or not you turn on the AC.

Something else you might notice is that the material of your window treatment can have a big impact. Honeycomb shades, which are made with several insulating layers designed to repel heat, can stop temperature flow much more effectively than pleated shades.

white shutters in Southern California sunroom 

The same way, Polywood® plantation shutters, built from a completely solid faux wood compound, are able to block heat a to a much greater degree than hardwood shutters. That’s because natural wood can be porous, with random knots and holes that allow heat to flow through them easily. Polywood shutters, combined with seamless weatherstripping, make a solid seal on your window when shut, giving them that best in class r-value of 6 and up.

Up Your Home’s R-value

The numbers don’t lie. Your window coverings play a big part in how comfortable your house is. Could your home be a little cozier? We’ll help. Get in touch with the team at Sunburst Shutters Southern CA by calling 888-611-2474, or fill out our free appointment request form below.