EPA Releases Final Energy Star V6 Criteria

Window & Door
January 17, 2014

The U.S. Environmental Protection Agency has released the final Energy Star Version 6.0 Residential Windows, Doors, and Skylights Specification. V6 will take effect January 1, 2015, with the exception of the Northern Zone prescriptive and equivalent energy performance criteria for windows, which will take effect January 1, 2016. 

EPA revised the implementation date for the Northern Zone window criteria in response to concerns expressed by some stakeholders about the industry’s ability to have cost-effective, qualifying windows available in the Northern Zone by the originally proposed effective date. EPA believes that providing additional time will allow industry to increase product availability and identify cost-saving measures to further reduce incremental costs for consumers.

Energy efficiency requirements for windows under V6 are specified below:

Energy Efficiency Requirements for Windows

Climate Zone                U-Factor                     SHGC

Northern*                          ≤ 0.27                        Any

North-Central                    ≤ 0.30                      ≤ 0.40

South-Central                   ≤ 0.30                      ≤ 0.25

Southern                           ≤ 0.40                      ≤ 0.25

* The effective date for the Northern Zone prescriptive criteria for windows is January 1, 2016.

To qualify for Energy Star V6, windows may also have NFRC-certified U-Factor and, where applicable, SHGC ratings at levels that meet or exceed the equivalent energy performance criteria as specified below. These criteria allow windows with energy performance equivalent to the prescriptive criteria to qualify in the Northern Zone. Equivalent performance criteria are not applicable to the North-Central, South-Central, or Southern Zones or to Doors or Skylights.

Equivalent Energy Performance for Windows

Climate Zone                U-Factor              SHGC

Northern*                       = 0.28                  ≥ 0.32
                                         = 0.29                  ≥ 0.37
                                         = 0.30                   ≥ 0.42

* The effective date for the Northern Zone equivalent energy performance criteria for windows is January 1, 2016.

Download the final Energy Star Version 6.0 Residential Windows, Doors, and Skylights Specification in its entirety here.