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The popularity of HERS-rated homes is clear, with 38 percent of all new homes getting HERS rated in 2015[1]. This figure is indicative of the importance of this energy performance marker to both builders and homebuyers and the growth trend is likely to continue. As builder adoption of the HERS score expands, how can HERS raters help builders make the transition from standard code-built homes to HERS-rated homes more efficiently?
HERS Raters as Design Consultants
“The number one thing that builders can do to make the transition from baseline code-built homes to HERS rated homes is consult with a HERS rater early on in the design phase of a new home,” according to HERS Rater Kevin Smith, Energy Engineer with Energy Wise Solutions, a Charlotte, NC based company specializing in home energy efficiency design, testing and certification. Smith says that with the growing prevalence of energy efficient construction, he estimates that 40 percent of builders are “sustainability and energy-efficiency focused” and 60 percent are budget conscious. He believes it is possible for builders to be both energy efficient and cost conscious, but not involving a rater early in the design process and not working directly with the rater and tradespeople is a hindrance to achieving cost-effective energy efficiency.
“Reaching the desired performance target is a function of having all of the trades well informed and trained before construction starts,” Smith says. He advises that builders meet with a HERS rater who can review the design plans, emphasize the critical details that trades must execute on to achieve the desired outcome, and reinforce the importance of training and education to achieving aggressive energy performance targets.
“It’s common for HERS raters conducting inspections to find big holes in ceiling top plates in the interstitial layer or in the ceiling bordering the attic. Uncorrected, these air leakage pathways lead to decreased comfort, poor insulation performance and reduce the air tightness of a home,” Smith notes. “These problems can usually be fixed by caulking or canned foam, but if the technicians don’t have a good understanding of what they’re looking to accomplish with these products, you can still have a lot of air leakage and they wind up missing key areas like the top plates.”
Articulating the need for continuous training of all trades, Smith says that in addition to a basic understanding of how buildings function as a system, contractors need training, checklists of critical steps to take and inspection to verify that jobs are done correctly. He believes that the workforce demands materials in both English and Spanish language as well as mobile-friendly formats for easy field access.
Insulation Installation Guidance for Builders New to HERS-Rated Homes
Smith advises that builders become familiar with both RESNET’s insulation grade standards and the manufacturer’s guidance on optimal installation of their products. “Builders should be well versed in what the manufacturers’ requirements are for proper installation – in some cases, these requirements will be more stringent than RESNET requires – but the end result is products installed as the manufacturer’s intended that also meet RESNET Grade One standards, which will ultimately increase the performance of those products.”
Regarding the HERS score impact of a RESNET Grade Two insulation installation, Smith says he believes it is possible for builders to get a low HERS Score with Grade Two installation, but that the builder would have to install very expensive equipment to get there. “By reinforcing the importance of Grade One installation, training to achieve it and holding people accountable for being knowledgeable about the manufacturer’s recommend installation procedures and the RESNET requirements for Grade One, builders can get the quality they deserve.”
Smith said because he consults with builders early, providing guidance on critical details and emphasizing proper training, he sees a high percentage of homes reach RESNET Grade One on first inspection. “We’re able to correct issues when they’re identified as well, so that the builder is able to achieve the energy efficiency targets they want cost-effectively.”
Energy Wise Solutions has provided HERS ratings to more than 480 homes in North and South Carolina and has been in business since 2005.
[1] U.S. Census Bureau Data for 2015. http://blog.batc.org/over-190000-homes-in-the-u-s-were-resnet-hers-rated/