Between The Gaps

Energy Star's standard revision was forced on the program by advances in the rest of the industry, says Sam Rashkin. But the makeover came at an awkward moment—because the same period brought other big changes. States were starting to adopt the tougher, new 2003/2004 IECC. Then, Resnet, the national organization of Home Energy Rating Service (HERS) raters, decided to modify its rating scale. In fact, Resnet turned its standard upside down: In place of the old scale running from 80 to 100, with a code-compliant house scoring 80 and a theoretical zero-energy house scoring 100, the new Resnet index sets the code-compliant house at 100 and a zero-energy house at zero. (On the new scale, a lower score means a better house.)

KEEP IT SIMPLE: Here, framers have nailed OSB sheathing to the bottom edge of roof trusses before building down a stepped tray-ceiling soffit. The OSB provides an air barrier between the conditioned room and the attic and gives attic insulation a flat place to rest.

Credit: Advanced Energy Corp.

Bruce Harley chairs Resnet's technical committee. Harley sees an advantage to the new index's wide scale and its emphasis on the ideal zero-energy maximum. “We wanted people to see the difference between [an incremental improvement and a real breakthrough],” he says. “If you've got a base case at 80, Energy Star at 86, and zero energy at 100, it's hard to differentiate. Now, the base case is 100, Energy Star is 80 or 85 (depending on your climate), and you've got a long scale ahead of you on the path to a zero-energy home.”

But some energy raters warned of confusion. Vermont rater Patrick Haller, for example, commented that “[this] could set us back several years in educating builders about threshold scores.” Changing the HERS system while Energy Star was also changing could be a management nightmare in the field, worried Haller, especially for states with limited resources and many small builders to reach: “We expect to lose participation.”

But Haller now says things haven't gone so badly. “Our worst expectations have not been realized,” he told BUILDER in March. “In our area, builders are testing the newer system and clearly want to succeed.” Bathtub and shower areas are proving a pesky detail: “General contractors seem to find it difficult to identify the sub responsible for putting in the air barrier. The difficulty is in the sequencing of work.” Scheduling inspections has also been an issue—“the builders are giving very little time from request of inspection to putting up Sheetrock,” Haller says, “but we're pleasantly surprised by how flexible the builders are.”