Eye On Energy_DWM

Volume 11, Issue 2 - March 2010

Eye On Energy

Get Ready for Energy Star® Homes Changes
The Windows Program Isn’t the Only One Changing
by Arlene Zavocki Stewart

With the shake-up surrounding the transfer of the Energy Star® windows program from the U.S. Department of Energy to the U.S. Environmental Protection Agency, the new criteria for Energy Star homes often has been overlooked by the window industry. Slated to go into effect on January 1, 2011, the program updates not only have an increase in efficiency but also an increase in responsibility and costs for builders and energy-raters. (The program changes will cost an average of $4,500 with averaged annual savings around $500, according to EPA’s Savings and Cost Estimate Summary.)

Energy Star Home qualification still will have two paths, but both prescriptive and performance paths will be restricted by size. If the proposed home is larger than the benchmark home according to number of bedrooms, the performance path will have to be used. Additionally, the qualifying Home Energy Rating System (HERS) Index for that home will be more stringent as the square footage increases.

Energy Star doors, windows and skylights are now mandatory for the prescriptive path with additional stringency in solar heat gain coefficient (SHGC) (for zones 1-3) or U-factor (for zones 4-8) for homes with greater than 15 percent window to floor area. In the performance path, doors, windows and skylights must meet or exceed the prescriptive requirements within 2009 International Energy Conservation Code (IECC) “to ensure that an effective thermal envelope is provided with every qualified home.” The definition for window area in the Energy Star Reference Design has been modified to align with the 2009 IECC also, with up to 0.75 percent allowed for decorative glazing.

The EPA, which has administered the Homes program since its inception, now has ramped up focus on how these provisions are installed. The current version requires a mid-point inspection for a single thermal bypass checklist. The 2011 criteria also has added HVAC and water management checklists, plus builder and HVAC contractor checklists.

“We still expect that only one mid-point inspection will be needed,” said Sam Rashkin, national director for the Homes program at a training session in December, “but the inspection time will increase.”

Moreover, to ease the compliance process, EPA has increased the total allowances for builder-verified items from four to eight. The eight allowances encompass all of the requirements of the checklist, including the new section for reduced thermal bridging.

Manufacturers may want to review their installation instructions for compatibility with the new Thermal Enclosure System Rater Checklist instructions: “Framing at windows shall be limited to a maximum of one pair of king studs and one pair jack studs per window opening to support the header and window sill. Additional jack studs shall be used only as needed for structural support and cripple studs only as needed to maintain on-center spacing of studs.”

Further, EPA clarified concerns about structural integrity submitted during the first comment period.

“Raters need not direct builders to remove framing, but instead shall simply determine compliance by confirming that the specified details have been used and by assessing the amount of framing in the home that has no apparent or documented structural purpose … Vertical framing members shall either be on-center or have an alternative structural purpose that is apparent to the rater or documented by the builder, architect or engineer. No more than five percent of studs may lack an apparent or documented structural purpose, which is equivalent to one vertical stud for every 30 linear feet of wall, assuming 16-inch stud spacing. Therefore, if installation requirements exceed these parameters, providing engineered documentation that builders can provide to raters may reduce construction delays.”

The water management system rater checklist indicates door and window openings fully flashed, including pan flashing at sills, side flashing that extends over pan flashing, and top flashing that extends over side flashing. Likewise, the HVAC system quality installation rater checklist indicates doors to garage should be gasketed or made substantially airtight.

The current implementation date is January 1, 2011, with a grace period of one year to implement the new installation checklists. The EPA is offering a series of free webinars to support all of its Energy Star programs, including one about the 2011 criteria on April 7.

Arlene Zavocki Stewart is president of AZS Consulting Inc., The views and opinions expressed in this article do not necessarily reflect those of this magazine.
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