DOE to Strengthen Energy Star Criteria in Two Phases

August 7, 2008

The U.S. Department of Energy has released its Energy Star Windows, Doors, and Skylights Draft Criteria and Analysis, which outlines a two phase approach to tighten requirements to carry the label. Pending a stakeholder meeting scheduled for August 13th and one additional month to accept further public comment, the final numbers will be determined this fall with August 3, 2009 said to be the earliest effective date for phase one of the changes.

In a letter to stakeholders, Richard Karney, DOE program manager for Energy Star notes that the draft criteria differ from the current Energy Star requirements in several ways:

  • Revised climate zone boundaries more closely matching national and state energy code climate zones
  • A separate zone and stringent prescriptive criteria for windows in the Pacific Northwest in phase one
  • In the heating dominated North, outside of the Pacific Northwest, windows must meet minimum annual energy performance. Products can qualify with a mix of U-factor/SHGC combinations.
  • Traditional prescriptive maxima in the Central and Southern regions without equivalent performance criteria (trade-offs).
  • Products must meet a new insulating glass unit certification requirement relying on the anticipated change in the National Fenestration Rating Council program.
  • Separate criteria for swinging entry doors that vary according to glazing area rather than climate zone.
  • Revised skylight criteria that are more stringent, though less aggressive than window and door criteria.

The following tables highlight the changes proposed for phase one, beginning in 2009, and phase two, beginning in 2013. Also below are maps showing the changes in the Energy Star climate zone.



A 103-page document outlining the details of the proposed criteria and supporting documentation is available here. DOE points out that it is initially only proposing criteria for the highest-volume windows, doors, and skylights. After these criteria are finalized, DOE will evaluate the feasibility of developing equivalent performance criteria for dynamic glazings and the necessity of establishing separate criteria for impact-resistant products.

“DOE thanks all stakeholders for their valuable input, which was instrumental in drafting achievable criteria meeting the DOE objective of increasing energy savings,” Karney notes in the letter to stakeholders. “DOE looks forward to hearing from all stakeholders registered for the meeting on August 13,” he notes as well.

Input is also welcome from those not attending next week’s meeting. Written feedback can be sent by e-mail to with “Criteria Revision” in the subject line. The public comment period will begin August 13 and last for one month.

Look for a full report on the August 13 stakeholder meeting in the August 20th issue of WDweekly.