Last year the U.S. Department of Energy (DOE) announced that eight states would be part of a three-year Residential Energy Code Field Study. Once completed, the study will provide an unprecedented opportunity to develop new strategies for education, training, and outreach for improving the energy efficiency of single-family homes, as well as a measurement of the impact those activities have on residential energy use.
Last month, DOE presented the initial field data findings from six of the eight participating states. While previous studies showed low compliance with energy codes in many states and jurisdictions throughout the U.S., the DOE field study data shows that most homes are performing at or better than code, on average, and that homeowners are finding significant cost savings. For instance, DOE estimated a one-year energy cost savings potential of $427,428 in North Carolina based on data gathered in the state’s field study.
- Window U-factor and SHGC/ Code requirement varies depending on climate zone: This key item was consistently better than code across all states, and no state had more than three observations where windows were worse than code
- Duct leakage/ Code requirements range from 4 cfm/100 sq. ft. to 12 cfm/100 sq. ft.: Findings here were generally at or better than code across the board.
- Frame walls/ Code requirements vary depending on climate zone (R-13 in warmer climates to an R-20 in colder climates): This key item was most consistent with code requirements and wall R-values were generally exactly as the code mandates
Overall, the initial DOE Residential Energy Code Field Study findings demonstrate the success of energy codes as an effective policy tool for driving energy efficiency. It also demonstrates the diligence of builders and local building officials in ensuring compliance with the energy codes adopted in their states.
A few additional takeaways for builders are:
- Builders should pay special attention to the lighting that they are installing. The data seemed to indicate that in some states about half of builders were installing no high-efficacy lamps. LEDs or Compact Fluorescent Lamps (CFLs) can be used to meet the high-efficacy lighting requirements of the IECC.
- While most homes met the requirements for duct and envelope leakage testing, this requirement will become more difficult to achieve when states move to more recent versions of the IECC. This means builders will have to pay greater attention to how their homes, and ductwork, are sealed.
Excerpts from this article were taken from builderonline.com
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