DOE Issues New, More Stringent Energy Star Criteria

Industry offers initial feedback at August stakeholder meeting

Manufacturers wanting an Energy Star label on their windows will need to make some significant product line changes, including potentially, the use of triple glazing. The Department of Energy issued new proposals for more stringent Energy Star criteria for windows, doors, and skylights in August, and hosted a public stakeholders meeting to gather industry feedback.

Speaking at that meeting, Richard Karney, DOE program manager for Energy Star, said that the more stringent requirements are necessary to make the Energy Star label a "differentiator" in the market again, pointing to the fact that more than half the windows sold in 2007 carried the label and that the current criteria are basically the same as code in many states. DOE is planning a two phase approach to tighten requirements to carry the Energy Star label.  With final numbers set to be issued this fall, the first set of more stringent requirements will go into in effect August 3, 2009 at the earliest, and a second even more stringent set of criteria will kick in sometime in 2013. With the first set of criteria, the goal is to meet or beat the 2009 International Energy Conservation Code without requiring major product redesign, Karney noted.  "It's in the second phase that we really want to beef up the program and give manufacturers some lead time to do it." 

The second phase has some manufacturers concerned. John Lewis of the American Architectural Manufacturers Association noted at the meeting that while the association had not had enough time to develop an official response, a number of AAMA members had already expressed concerns that Energy Star products will be "priced out of the market" in phase two. Ray Garries of Jeld-Wen Inc. questioned the wisdom of pushing Energy Star requirements to a level where triple glazing becomes a necessity. "We've made a tremendous investment in Energy Star product lines and want to continue," he emphasized. "Speaking for our customers, affordability is something we need to consider."  He questioned a number of the assumptions made in determining the new criteria, noting that his company estimates the payback for homeowners opting for products meeting the second round of Energy Star criteria to be a half to a quarter of what DOE expects. Pointing to DOE estimates that purchase of Energy Star products meeting the new criteria will produce $100 million in energy savings a year, Garries suggested that consumers will have to spend between $1 billion and $2 billion more to buy those products.

Fig. 1

The Specifics

  • The draft criteria differ from the current Energy Star requirements in several key ways, according to DOE:
  • Revised climate zone boundaries more closely matching national and state energy code climate zones (Fig. 1)
  • 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 goals. 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.


Table 1
shows the current Energy Star criteria and the proposed criteria for 2009 and 2013. Table 2 shows the alternative U-factor/SHGC combinations that products can have to qualify in the two Northern climate zones. Stephen Bickel of D&R International, which administers the Energy Star program for DOE, suggested at the stakeholder meeting that the phase one criteria "should be able to be met with products that are already available or with an upgraded glass package." The one exception, he noted, was in ES1-the southernmost Energy Star climate zone-where new U-factor requirements in the Energy Star criteria will match the more stringent U-factor requirements expected to be in the 2009 International Energy Conservation Code. The new criteria and elimination of tradeoffs allowed in the current Southern zone are likely to eliminate "continuous aluminum windows" from the Energy Star program, he also suggested.

Bickel predicted the first round of changes will produce a modest decline in Energy Star market share, except in the South. The second round of Energy Star criteria changes are "much more stringent," he added, noting it will be then, that "We reestablish Energy Star as a differentiator. There will be a price premium for Energy Star-and a decline in Energy Star market share." The proposed criteria will require redesigned products in the two Northernmost zones and overall, he predicted, manufacturers will need to offer distinct product lines for the North and South. 

In the Northern zones, maximum U-factor criteria are reduced quite significantly, going from the current .35 to a .28 in ES1 and .26 in ES2 in 2013. Pointing to the more stringent phase two U-factor criteria in the Northern zones, Bickel noted some windows-all triple-pane--already qualify. The use of triple-glazing adds about 15 percent to the marginal cost of these products, he added, which can be justified as far as the energy savings. He admitted that some manufacturers have already suggested the increased cost will be much more.  "I've already heard it can't be done,"  but, he said D&R had also looked at real numbers coming from two manufacturers that produce triple pane units in volume that show 15 percent marginal cost estimate to be about right.

The most common piece of feedback that came back from industry representatives at the meeting was that more time is needed than the 30-day period initially scheduled to provide public comment.  Mike Fisher, representing the Window & Door Manufacturers Association, was one of many asking for more time to offer input. He also asked DOE to consider January 1, 2010 and January 1, 2015 as implementation dates for phase one and phase two of the changes. "Changing a window to change the thickness of the IG or allow for triples means lot of testing. We should have five years between phase one and phase two." The January 1 implementation date is also better because manufacturers are less likely to be in the midst of their busy season. Fisher also expressed concerns about the complexity of the new criteria, urging DOE to consider "simplicity" for the sake of the consumer.  

Garries also urged greater simplification of the program. "Complications in maps and tradeoffs make it harder to upsell consumers on Energy Star," he suggested. He also urged DOE to reconsider establishing separate Energy Star criteria for new construction-where code generally sets minimum performance standards already-and the replacement and remodeling market, where codes have less of an impact. 
Not all window manufacturers at the meeting were unhappy with the proposed criteria. "I feel like a minority in this room," said Brandon Tinianov of Serious Materials.  His company, which recently acquired Alpen Windows, plans to launch a line of products meeting the second phase criteria already.  Noting that he appreciated the rigor that went into the development of the new numbers, he said he was frustrated by lack of enthusiasm for further progress in the market.  

Doors and Skylights
DOE has also established new criteria for both swing doors and skylights.  The swing door criteria, shown in Table 3, differ from the window criteria (which also cover sliding glass doors) in that there are no variations for different climate zones.  The criteria vary instead depending on the amount of glazing.  Describing the new swing door criteria at the stakeholder meeting, Alice Dasek of D&R noted that the goal of phase one is to establish the idea of the Energy Star label as a differentiator. It is phase two, however, where DOE seeks to drive that further.

Door manufacturers seemed pleased the new ratings criteria.  Steve Shrieber of Masonite started out by "applauding DOE" for the decision to eliminate different climate zone requirements for swing doors and simply establishing different requirements depending on the amount of glazing.  He even urged DOE to consider a lower U-factor number for opaque doors in the first phase. 

Steve Jasperson of Thema Tru also applauded the single climate zone, but suggested that DOE may need to go back and look at the half-lite criteria.  Under the current requirements, he noted, he can construct a fully-glaze  d door that will qualify, but the half-lite version of the same door will not, even though it constructed with more insulating core material and is more energy efficient.

The new skylight criteria include significantly lower U-factor and SHGC criteria than the current edition (Table 4). "Skylights seem to be treated more harshly than windows," said Roger LeBrun of Velux at the meeting. The new SHGC criteria, he added, can impair the light benefits of skylights-one of the main reasons people buy skylights.  LeBrun and ODL's Dave De Block also urged DOE to establish Energy Star ratings for tubular skylights that take into account the energy savings benefits they deliver through the use of daylighting.  

A 103-page document outlining the details of the proposed criteria and supporting documentation is available at the Energy Star Web site.  DOE points out that it is initially only proposing criteria for the highest-volume windows, doors, and skylights. These criteria and final effective dates will be decided sometime this fall. After it completes that task, DOE will evaluate the feasibility of developing equivalent performance criteria for dynamic glazings and the necessity of establishing separate criteria for impact-resistant products.

Despite some of the criticisms of the new criteria, most industry speakers at the stakeholders meeting expressed appreciation to DOE for already gathering input from the industry in establishing the new criteria. Shortly after the meeting, DOE extended its public comment period for the new criteria to October 17. Comments can be sent via email to with "criteria revision" in the subject line.