If you've heard a home improvement company suggest installing a radiant barrier in your attic to lower your energy bills, you might be wondering: Does this actually work? As home energy efficiency specialists, we've looked at the data and the building science to bring you a clear, honest answer. Here's what homeowners need to know.
What Is a Radiant Barrier? A radiant barrier is a type of reflective material, usually aluminum foil, designed to reflect radiant heat rather than absorb it. Unlike insulation, which slows heat transfer through conduction, radiant barriers are all about reflecting heat back toward its source.
Do Radiant Barriers Work? Yes—but only if installed correctly and under the right conditions. Hot and sunny climate creates ideal conditions for radiant barriers if your attic meets the following criteria:
Your roof receives a lot of direct sunlight.
You have HVAC ductwork running through the attic.
Your attic is already insulated to at least R-30.
In these situations, radiant barriers can reduce attic temperatures and lower cooling costs by 5% to 10%. Not huge, but potentially worthwhile.
The Right Way to Install a Radiant Barrier To get real results from a radiant barrier, installation method matters more than you might think:
Best method: Staple or attach the radiant barrier to the underside of the roof rafters or decking.
Maintain an air gap: The foil must face an open air space to effectively reflect heat.
Ensure attic ventilation: Radiant barriers work best when paired with ridge, soffit, or gable vents.
Avoid laying it on insulation: This cheaper method is less effective and loses performance as dust builds up.
Also, use perforated barriers to avoid trapping moisture and creating mold issues.
When Radiant Barriers Aren't Worth It In cooler climates, shaded roofs, or homes with no ductwork in the attic, radiant barriers offer little benefit. And they do not substitute for proper insulation and air sealing. If you're looking for big savings, those should be your first upgrades.
Our Take as Energy Experts At Earthwise Efficiency, we focus on real, science-backed solutions that lower your energy bills and make your home more comfortable. Radiant barriers can help if installed the right way, but they're not magic. We often recommend them only as a supplement to proper insulation and attic air sealing.
Want to know if your attic is a good candidate? Schedule a free attic evaluation with us. We'll give you an honest assessment—no hype, just facts.
Bottom Line Radiant barriers can reduce cooling costs in homes, but only if they're installed correctly and paired with proper insulation and ventilation. Don't fall for overhyped claims. Trust building science—and talk to a pro who puts your home's performance first.
Ready to Make Your Home Cooler and More Efficient? [Contact Earthwise Efficiency for a free attic evaluation] or give us a call at (801) 252-6121.
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