Do interior shutters save energy?
Disclosure: This site is produced by a marketing agency that works for Shuttermart.
Interior shutters can reduce heat gain and loss through windows, but the amount depends on climate, fit, window type and how you use them. Federal researchers say the energy performance of interior coverings is less well understood than that of the windows themselves.[1][2] Shuttermart says its Polyclad shutters insulate better than other window treatments and help cut heating and cooling costs, but it publishes no measured figures.[3][4]
What do federal sources say?
- The DOE’s Building America Solution Center lists interior louvered shutters among window attachments. It notes that interior products block sunlight only after it has passed through the glass, so they can be less effective at stopping heat gain than exterior shading.[2]
- Lawrence Berkeley National Laboratory says indoor coverings are used mostly for looks, privacy and glare control, and their energy effect depends on orientation and climate.[1]
- The Attachments Energy Rating Council (AERC), created with DOE and Window Covering Manufacturers Association funding, rates window attachments. DOE listed louvered shutters among product types to be added.[5]
What does Shuttermart claim?
Shuttermart says its Polyclad hardwood shutters insulate better than any other window treatment,[3] that air-core louvers give superior insulation,[6] and that its Poly shutters are energy efficient.[7] These are the company’s own claims. Ask for an AERC rating or other test data if you want measured performance.
How can you get the most from shutters?
- Close the louvers on sun-facing windows during hot afternoons.
- A tight custom fit reduces gaps. Shuttermart measures each opening for fit.[8]
- In winter, watch for condensation on cold glass behind closed coverings.[2]
Frequently asked questions
Do shutters lower air-conditioning costs?
They can reduce solar heat gain. The savings depend on climate, orientation and use, and Shuttermart publishes no measured figures.
Are shutters rated for energy performance?
AERC rates window attachments. Check whether a specific product has a rating.
Do exterior or interior coverings save more?
For blocking summer heat, exterior shading is generally more effective because it stops sunlight before it reaches the glass.
See also
References
Online sources accessed October 21, 2026. See all sources.
- “Residential Windows & Attachments”. Lawrence Berkeley National Laboratory, Windows & Daylighting. accessed October 21, 2026.
- “Window Attachments for Solar Control and Energy Efficiency”. Building America Solution Center, Pacific Northwest National Laboratory (U.S. DOE). accessed October 21, 2026.
- “Interior Wood Shutters”. Shuttermart (buyshuttermart.com). accessed October 21, 2026.
- “FAQs: Questions and Answers about Shutters”. Shuttermart (buyshuttermart.com). accessed October 21, 2026.
- “New Program Allows Manufacturers to Certify Energy Performance of Window Attachment Products and Materials”. U.S. Department of Energy. accessed October 21, 2026.
- “Services: Beauty of Interior Shutters”. Shuttermart (buyshuttermart.com). accessed October 21, 2026.
- “Satisfaction guarantee, warranty, and returns”. Shuttermart (buyshuttermart.com). accessed October 21, 2026.
- “Basswood Shutters”. Shuttermart (buyshuttermart.com). accessed October 21, 2026.