Energy Star Zone Map

Energy Star Resource Center

The Energy Star qualification criterion for all zones changed in 2010 and the fenestration industry has been affected in three significant ways. These changes will have a substantial impact on the consumers of windows and doors.
  • The Energy Star Zone Map (shown to the left) was modified. The Northern Zone is expanding and as a result, the zones for the Southwestern tier of states: California, Arizona, New Mexico, and Texas have been altered. There are less apparent changes in other areas of the country which must also be observed. Even though they are less dramatic, they significantly impact consumers in those specific regions.
  • U Value & Solar Heat Gain Coefficient (SHGC) requirements for each zone were changed. Windsor has glazing options that meet the criteria for all zones. For the Northern Zone, there are two levels that meet the qualifications; the Prescriptive and the Equivalent Energy Performance. Windsor's Energy Star qualified options will meet the Prescriptive requirements of U-Value <= 0.30 and any SHGC.
  • Doors now carry separate requirements from windows. Under the previous guidelines, windows and doors were required to meet the same U-Value & SHGC for a zone. Since this change in 2010, doors will have one requirement based on glazing style regardless of zone. See the Doors Chart in the graphic to the left. All of Windsor’s doors fall under the >1/2-lite requirements of U-Value ≤0.32 and SHGC ≤ 0.30.

Manufacturers began reporting to the new criteria and labeling requirements as early as January 1, 2010, and were required to make a complete conversion by April 1, 2010. The new label requirements are designed to help consumers understand the Energy Star qualification criteria and the implications to their unique application and location. The new labels also provide the specific Air Infiltration Rating for that product, rather than simply supplying an acceptable range for the product type.

Energy Star is not a code, but many builders and homeowners use Energy Star as a benchmark of comparison and as a decision making tool when purchasing fenestration products. Some local building codes also choose to amend their local requirements to the Energy Star levels.

For more information on which Windsor products meet Energy Star requirements in your area, refer to the Energy Performance Search Tool.

Additional Information