[OBSOLETE] Analysis of HERS Index Scores for Recent Versions of the International Energy Conservation Code (IECC)

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The EnergyGauge HERS software tool was used to examine the IECC Standard Reference Design (IECC SRD) configuration for one-story 2000 ft2 and two-story 2,400 ft2 single-family homes in sixteen representative U.S. cities. IECC SRD homes were configured for the 2006 IECC, the 2009 IECC and the 2012 IECC. Two additional set of analysis were conducted, both using the 2012 IECC SRD with enhanced equipment: 1) with equipment configured to meet the 2015 National Appliance Energy Conservation Act (NAECA) equipment requirements and 2) with equipment that is on the cusp of significant market penetration with efficiencies greater than the 2015 standard.HERS simulations for each home were conducted for both a best case home orientation and a worst case home orientation. For the overall best-case configuration (2-story home with north-south glazing orientation), results show a nationwide average 12.3% increase in code stringency between 2006 and 2009, a 19.2% increase between 2006 and 2012 and a 26.0% increase between 2006 and 2012 with 2015 NAECA equipment. Incorporating higher efficiency equipment on the cusp of significantly broader market adoption due to federal initiatives resulted in an average 35.7% savings with respect to the 2006 IECC.

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