The U.S. Department of Energy (DOE) released its Energy Star for Windows, Doors and Skylights Revised Draft Criteria and Report late yesterday. DOE says this latest draft takes the comments it received into consideration as well as the criteria approved for the 2009 International Energy Conservation Code (IECC) and the criteria set forth for the 2009-2010 tax credit in the American Recovery and Reinvestment Act (ARRA) of 2009, according to the DOE. Taking these and other factors into consideration, the DOE has made several changes to the draft. Energy Star criteria, specifically:

1. A reduction in the number of climate zones to four. It also has returned to geographic zone names;

2. An adjustment to the windows criteria to limit tradeoffs in the North;

3. An adjustment to the U-factor for the ≤½-lite category of swinging entry doors and a change in the SHGC to match IECC levels;

4. Changed skylight criteria based on IECC levels;

5. Suspended Tubular Daylighting Devices from the program until industry collects a sufficient body of test results; and

6. Delayed beginning work on criteria for Phase 2 until late fiscal year 2009.

There are some additional items of interest in the draft criteria.

In September of 2008, the International Code Council (ICC) finalized the 2009 IECC, whose levels exceed those of ENERGY STAR in several regions. DOE says ENERGY STAR must consider the stringency of IECC levels when evaluating which criteria will yield savings above prevailing building codes. This is true in the wake of the passage of the American Recovery and Reinvestment Act of 2009; because the law requires states to adopt the most recent code and enforce it to receive additional state energy grants, states are likely to adopt the 2009 IECC more quickly than they might have otherwise.

On February 17, 2009, President Obama signed into law ARRA, which extends and revises the tax credit for windows, doors, and skylights. (CLICK HERE for related article.)

While the previous tax credit for fenestration products applied to ENERGY STAR qualified products, the new tax credit specifies energy performance criteria, a maximum 0.30 U-factor and maximum 0.30 SHGC, for the entire country, regardless of climate zone. DOE considered this fact when reviewing ENERGY STAR criteria levels across the country.

Although the tax credit applies across the United States, DOE considered it most closely when reviewing the proposed criteria for the North, the zone that would most benefit from the application of this low U-factor. Meeting or exceeding code is a minimum requirement for ENERGY STAR criteria, and ICC set the final 2009 IECC prescriptive criteria for the regions corresponding to ES5, ES5a, and ES4 at a maximum U-factor of 0.35 and no rating for SHGC.

In revising the draft criteria for the northern climates, DOE says it considered its original analysis, stakeholder comments, the newly enacted federal tax credit and final 2009 IECC prescriptive criteria.

The revised criteria consolidate the three northern zones (ES5, ES5a, and ES4) into a single zone and greatly simplify trade-offs, as requested by stakeholders. DOE tightened the U-factor criterion to the 0.30 level of the tax credit to ensure ENERGY STAR intersects with it. To maximize the number of products qualifying in this zone at the 0.30 maximum U-factor, DOE set no SHGC criterion rather than carry over the tax credit’s SHGC maximum. The majority of windows in the market meeting the 0.30 U-factor, however, will also meet the tax credit’s 0.30 SHGC level, because the 7 median SHGC for products with U-factors ≤ 0.30 is 0.27. The revised tax credit of 30 percent, up to $1,500 total, will help cover the cost of producing windows that qualify for the credit.

The Industry Reacts

Jeff Lowinski, vice president advocacy and technical services, for the Window and Door Manufacturers Association (WDMA), says the DOE did take into account many of the comments WDMA made on behalf of its members.

“They addressed the issue of too many zones, differing requirements, etc.,” says Lowinski who adds that the WDMA is currently looking at the new draft in more depth. The association will have more information as to what additional comments they may make on this draft in the coming days.

Edgetech IG’s Jim Plavecksy, a DWM blogger, also is pleased that DOE went back to four zones.

“It makes matters less confusing,” he says.

Lowinski does point out, however, that Energy Star is not in line with ARRA, a point Plavecsky also addresses.

“I like what they are doing in the Northern Zone with both U-value and SHGC,” says Plavecsky. “Putting the U-value in line with the tax credit requirement makes perfect sense. But why limit this change to only the Northern Zone? U-value plays a dramatic role in energy conservation, so why not put all zones, except maybe the southern, in line with the tax credit as well? By not specifying a maximum value for SHGC in the Northern Zone, DOE is recognizing the significance of possible and probable solar heat gain advantages, and this makes perfect sense. Too bad the tax credit requirements for SHGC are now permanently fixed because this limits the ability to make Energy Star as compatible as possible with the tax credit requirements.”

But Lowinski adds that the technical debate regarding energy requirements should go on in a technical forum, not a legislative one.

Wayne Gorell, president of Gorell Windows and Doors, believes the new draft criteria could be even more stringent.

“I don’t think they have gone nearly far enough,” he says, adding that this applies to the tax credit requirements as well.

“As far as Energy Star goes (and the same goes for the tax credit), the tougher the achievable standards, the better,” he says. “We have the ability to make windows with a U-value well under 0.2 today, so why are they setting the standard more than 50 percent worse, at 0.3U?”

He adds that the U-value standards should be set at or close to 0.2U, at most 0.25U, to get the most benefit for our country.

“This is probably not what a lot of manufacturers want to hear, but we need to focus on the reason for Energy Star and the reason for the tax credit. The requirements should not be based on what is easy to achieve. We need to do what is best for our country and its citizens, and that is saving more energy to work towards energy independence.” Gorell says that the industry should also be taking into consideration the fact that technology will continue to improve.

“We are short-changing consumers who buy windows today from saving the most energy they possibly could save for many years to come,” he says. “Most consumers do not change their windows more than once, so missing the opportunity to save the maximum amount of energy now will have a long-term impact.”

Impact on Skylight Industry
Another change to the revised criteria includes a change for skylights that, according to the DOE, would encourage superior product performance and maximize potential savings. (Click on the full draft criteria at the end of this story to see the chart regarding skylights, which appears on page 9 of the draft.)

Roger LeBrun, product certification engineer for Velux America Inc., says his company will support the skylight criteria, as it accounts fairly for the technology that is available and currently cost-effective.

However, there is one item in the criteria regarding tubular daylighting devices (TDD) with which LeBrun disagrees. The DOE had deferred setting Energy Star criteria for these products until there was a sufficient body of physical test results on which to determine relative performance.

“As of the date of this report, no additional test results are available, and DOE has no choice but to suspend TDDs from the Energy Star program pending the availability of a sufficient body of test results,” according to the criteria.

LeBrun says he is very disappointed that tubular daylighting devices were proposed for elimination.

“There is no reason for ENERGY STAR to dismiss the category on the basis of a sub-optimal test method they accepted for many years, since the thermal energy penalty from TDDs is far outweighed by their lighting energy savings. If nothing else, these are the most efficient ‘lighting devices’ one can buy. They just need to be as tight as any good door or window. Why else would the National Green Building Standard award extra points when they are used in rooms where windows can’t be used?”

The DOE is taking comments from now until March 25. CLICK HERE for information on where to send comments.) The final criteria will be published on March 31, 2009. The effective date for phase 1 criteria is January 1, 2010.

CLICK HERE to view the full draft criteria.



  1. […] doors, windows and skylights. The first phase of the criteria goes into effect on January 4. (CLICK HERE for related […]

  2. Thanks for posting this article, I was confused by the changes to the Federal Tax incentive that requires lower SHGC as that does not work in the Northern areas where you want Solar Gain most of the year and you block out the sun with the Overhangs (eaves) not with the SHGC value. These changes made the Energy Star, and Oregon Department of Energy Passive Solar Prescriptive path somewhat incongruent with the Federal Incentives. Good article.

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