The same is true for houses. Today’s homeowners looking for ways to improve their home’s energy performance are increasingly choosing insulated siding — vinyl siding with rigid foam insulation that is laminated or permanently attached to the panel. Think of it as adding an extra layer to ward off the cold.

Most exterior walls have insulation in between the wall studs but allow significant energy loss through the studs themselves, which are poor insulators. This is called “thermal bridging.” Insulated siding improves energy efficiency by reducing thermal bridging. Like a blanket, it is continuous insulation over the studs, which helps homes stay warm in winter and cool in summer.

In a recent study of five homes retrofitted with insulated siding, researcher Newport Ventures found an average improvement in air tightness of 11 percent, an average energy savings of 5.5 percent, and an improvement of 2.0 to 8.0 points in the homes’ Home Energy Rating System index, the nationally recognized scoring system for measuring a home’s energy performance.

“Replacing a home’s exterior cladding with insulated siding can improve the thermal performance of the walls while reducing heating and cooling energy costs,” said Jery Y. Huntley, president and CEO of the Vinyl Siding Institute, Inc., a Washington, D.C.-based trade association for manufacturers of vinyl and other polymeric siding and suppliers to the industry.

Designed to reach higher levels of rigidity, stability and thermal resistance — “R-value” — insulated siding is subject to an array of regulations, standards and third-party quality assurance tests that determine how it is manufactured and marketed. Due to that rigor, a number of building and energy-efficiency programs have recognized that insulated siding qualifies as home insulation.

In addition, it has been recognized by the U.S. Environmental Protection Agency as a building product that can help qualify homes under the Energy Star Qualified Homes Program.

To learn more about how insulated siding complies with both energy codes and energy-efficiency programs, visit the building industry’s go-to resource “Insulated Siding as Home Insulation: Guide for Users and Energy Raters” at www.insulatedsiding.info.