Each year, RESNET examines the trends across all homes that have received a HERS rating. RESNET has released its statistical abstract of homes HERS-rated in 2024, in the “Trends in HERS Rated Homes – A Statistical Abstract 2025”. RESNET began capturing HERS-rated homes in its National Buildings Registry in 2013. A new feature in this year’s report offers a glimpse at the top 20 states with the largest improvement in average HERS scores since 2013. • Eighteen of the top 20 states had double-digit improvements in their average HERS scores. • California, with its solar mandate for new residential construction, had the largest decrease in average HERS Index scores with 57 points. • Although there are limited HERS ratings in Maine, the Pine Tree State came in second with a 37-point reduction, followed by Nevada and Alabama with an 18 and 17-point reduction, respectively. • Eight states: Nevada, Arkansas, Georgia, South Carolina, Alabama, Tennessee, Oklahoma, and Arizona, have energy code efficiency levels of 2009 IECC or less, according to the Pacific Northwest National Laboratory’s tracking of state code efficiency levels (https://energycodes.gov/state-portal). • Three states, Mississippi, Missouri, and North Dakota, have no statewide energy code. This is a good indication that HERS Ratings are driving energy efficiency despite state energy codes. The map above displays the top 20 states that have had the greatest reduction in average HERS scores from 2013 to 2024. Read more findings in the “Trends in HERS® Rated Homes” 2025 Statistical Abstract.
